ALBERT

Description: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 298〈/p〉 〈p〉Author(s): Huimin Wang, Denis Y.W. Yu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Despite advances in traditional lithium-ion batteries in the past decades, its high cost has always been a bottleneck for large-scale applications. In this work, we demonstrate it is possible to replace expensive cathodes such as LiCoO〈sub〉2〈/sub〉 with inexpensive stainless steel to store energy via a stripping/deposition mechanism: during charging, the stainless-steel cathode removes charges by releasing metal ions into the electrolyte, and during discharge, the metal ions re-deposit on the electrode reversibly. An anion exchange membrane allows passage of anions to balance the charge and prevents cross-over of cations. We show here a battery with a stainless-steel cathode and a lithium metal anode with a high discharge voltage of 2.5 V and good reversibility. We also study the mechanism at the stainless-steel electrode, as well as the kinetics of the battery system. Our work can potentially reduce the cost of energy storage by turning common construction materials into cathode materials. In addition, a metal cathode undergoing stripping/deposition gives a theoretical energy density comparable to lithium-sulfur batteries and provides a new exciting direction for future energy storage development.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Xu He, Robert Büchel, Renato Figi, Yucheng Zhang, Yeonkyoung Bahk, Jun Ma, Jing Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The wide applications of particulate micromotors in practice, especially in the removal of environmental pollutants, have been limited by the low production yields and demand on high concentration of fuel such as H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉. Carbon/MnO〈sub〉2〈/sub〉 micromotors were made hydrothermally using different carbon allotropes including graphite, carbon nanotube (CNT), and graphene for treatment of methylene blue and toxic Ag ions. The obtained micromotors showed high speed of self-propulsion. The highest speed of MnO〈sub〉2〈/sub〉-based micromotors to date was observed for CNT/MnO〈sub〉2〈/sub〉 (〉2 mm/s, 5 wt% H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉, 0.5 wt% surfactant). Moreover, different from previous studies, even with low H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 concentration (0.5 wt%) and without surfactant addition, the micromotors could also be well dispersed in water by the O〈sub〉2〈/sub〉 stream released from their reaction with H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉. The carbon/MnO〈sub〉2〈/sub〉 micromotors removed both methylene blue (〉80%) and Ag ions (100%) effectively within 15 min by catalytic decomposition and adsorption. Especially high adsorption capacity of Ag (600 mg/g) was measured on graphite/MnO〈sub〉2〈/sub〉 and graphene/MnO〈sub〉2〈/sub〉 micromotors.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Cláudio E.T. Parente, Antonio Azeredo, Renata E. Vollú, Everaldo Zonta, Claudio E. Azevedo-Silva, Elcia M.S. Brito, Lucy Seldin, João Paulo M. Torres, Rodrigo O. Meire, Olaf Malm〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Our main goal was to investigate the potential accumulation of fluoroquinolones (FQs) in agricultural soils over extended periods of land use, predicting leaching and estimating risk quotients for soil microorganisms. Short to long-term of poultry litter fertilization (〈1–30 years) were evaluated for enrofloxacin (ENR) and ciprofloxacin (CIP) input, in addition to the emergence of plasmid-mediated quinolone resistance (PMQR) genes. High FQs concentration (range 0.56–100 mg kg〈sup〉−1〈/sup〉) were measured in poultry litter samples. In soils, FQs occurrence and risks have changed over the years. An accumulation trend was observed between short and medium-term fertilized soils (ST and MT soils), reaching a range of 330–6138 μg kg〈sup〉−1〈/sup〉 ENR and 170–960 μg kg〈sup〉−1〈/sup〉 CIP in MT soil, followed by decreased concentrations in long-term fertilized soils (LT soils). The environmental risk assessment showed a high ENR risk quotient (RQ ≥ 1) in ST and MT soils ranging (7–226) and high CIP risk (9–53) in LT soils. The detection of 〈em〉qnr〈/em〉S genes in the area with the lowest FQs concentration emphasizes the importance of a broader approach to environmental assessment, in which not only target compounds are considered. FQs soil-water migration model pointed out a high leaching risk in ST soil. To reduce risks, management measures to decrease antibiotic environmental load should be taken before poultry litter application. In addition, the high weathering of tropical soils contributing to possible fate of antibiotics to water resources through drainage basins should be considered.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518322914-fx1.jpg" width="320" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Florian Delerue, Jean-François Masfaraud, Jean-François Lascourrèges, Olivier Atteia〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Development of organisms that live on contaminated soils depends on toxicity as well as several physical and chemical soil properties. We aimed to identify plant bioassays most responsive to contaminants and not to confounding factors due to soil type differences. We implemented a multi-site approach in seven contaminated sites and used different ordinary plant bioassays (fourteen-day-shoot biomass and five-day-root and shoot elongation). Most of the sites were contaminated with polycyclic aromatic hydrocarbons (PAHs), and soils were sampled from areas of both high and low contamination. Bioassays were performed on ninety soil samples and were carried out with six model species. We performed analyses of regulatory PAHs and their derivatives content in the samples. Fourteen-day-shoot biomass responses depended on the site's origin, with an intricate response of plants that faced contrasted soil pH and organic matter content and various contaminant levels. Five-day-shoot and root lengths were informative when considering the most heavily PAH-contaminated site, since both measures exhibited a close dose-dependent response to PAHs but not to soil pH or organic matter content. For the other sites, elongation tests revealed tenuous effects somehow related to the presence of PAHs or their derivatives. We propose that tests based on plant development during their autotrophic phase (the fourteen-day-shoot biomass test in this study) are likely more sensitive to environmental stressors but less specific for contaminant-induced effects. Comparatively, tests based on early and heterotrophic plant development could be particularly more specific for soil contaminants, but the associated responses may be of low sensitivity.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Ying Wang, Bin Zhong, Mohammad Shafi, Jiawei Ma, Jia Guo, Jiasen Wu, Zhengqian Ye, Dan Liu, Hexian Jin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Pot experiment was conducted to investigate the effects of wood biochar (5%), bamboo biochar (5%), rice straw biochar (5%) and Chinese walnut shell biochar (5%) on growth, accumulation of heavy metals in moso bamboo, soil physical properties, and solubility of heavy metals in soil. The results revealed that dry weight of moso bamboo was significantly increased in treatments of wood biochar (5%), rice straw biochar (5%) and Chinese walnut shell biochar (5%) except bamboo biochar (5%). Application of straw biochar (5%) was most effective in enhancing plants biomass, with increase of 157%, 113% and 111% in leaves, roots and stems of moso bamboo. All treatments of biochar have significantly improved soil electrical conductivity with maximum increase of 360% compared to CK. In case of heavy metals accumulation, application of 5% bamboo biochar, straw biochar and Chinese walnut shell biochar has reduced Cu uptake in roots by 15%, 35% and 26%, respectively. The biochars have significantly reduced solubility of soil heavy metals with maximum reduction of 58.91 mg kg〈sup〉−1〈/sup〉 and 10.59 mg kg〈sup〉−1〈/sup〉 of Cu and Pb with application of rice straw biochar. It is concluded that dry weight of moso bamboo was significantly enhanced by all treatments of biochar except bamboo biochar.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Xin Zhong, Yuting Li, Xingkai Che, Zishan Zhang, Yiman Li, Binbin Liu, Qingming Li, Huiyuan Gao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Oxybenzone (OBZ), an active ingredient in most sunscreens, was recently shown to be toxic to humans, corals and other animals. This study is the first to demonstrate that OBZ can significantly inhibit photosynthesis and respiration in the leaves of a higher plant, cucumber. An OBZ suspension content as low as 0.228 mg/L obviously inhibited the photosynthesis and respiration of cucumber. OBZ instantly inhibits the electron transport of chloroplasts and mitochondria in cucumber leaves. Probit analysis demonstrated that the effective content for 20% inhibition of photosynthetic electron transport was 11.7 mg/L (95% confidence level). The inhibition of photosynthesis and respiration restricts carbohydrate synthesis and ATP regeneration, respectively, limiting the energy available for metabolic processes including the synthesis of vital organic macromolecules such as proteins and nucleic acids in plant cells. The inhibition of photosynthesis also enhanced the excess excitation energy in chloroplasts, resulting in overproduction of reactive oxygen species (ROS), and the inhibition of respiration aggravated this process. ROS accumulation adversely affects the structure and function of proteins, DNA and membrane lipids in plant cells, interfering with normal metabolism and even leading to plant death. Therefore, reducing the use of OBZ is important for protecting global ecological security.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉OBZ can enter cells to significantly inhibit photosynthesis and respiration in the leaves of a higher plant, cucumber. OBZ can instantly inhibit the electron transports of chloroplasts and mitochondria. The inhibition of photosynthesis and respiration would restrict the synthesis of carbohydrates and the regeneration of ATP, limiting the energy available for metabolic processes. The inhibition of photosynthesis increased the excess excitation energy in the plant cells, resulting in over-production of reactive oxygen species (ROS), the inhibition of respiration aggravated this process. The over-accumulation of ROS adversely affects the structure and function of proteins, DNA and membrane lipids in plant cells, interfering with normal metabolism and even leading to the death of plant.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518323415-egi10RK3ZTNDKH.jpg" width="253" alt="Image 103" title="Image 103"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Ling Zhu, Lihong Tong, Nan Zhao, Jie Li, Yizhong Lv〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Based on the interaction between mesoscopic biochar materials and nanomaterials, the synergistic mechanism of the two materials in the process of cadmium remediation was studied. K〈sub〉2〈/sub〉CO〈sub〉3〈/sub〉 activated porous biochar (KBC) loaded with nano-zero-valent iron (nZVI)/nano-α-hydroxy-iron oxide (nHIO) was studied. Macroscopically, batch adsorption experiments were carried out to describe the adsorption properties of the composites. Microscopically, the changes of surface chemical states were characterized by electron microscopy, XRD, FTIR and XPS. Combining the macroscopic and microscopic characteristics, the synergistic mechanism between biochar and nZVI/nHIO was comprehensively analyzed. The strong synergistic effects between biochar and nano-zero-valent iron (nZVI)/nano-α-hydroxy-iron oxide (nHIO) were found, which improved the removal efficiency of cadmium (Cd) in aqueous solution. The results showed that the loading of nZVI/nHIO reduced the specific surface area to 178.6 m〈sup〉2〈/sup〉 g〈sup〉−1〈/sup〉 and 272.2 m〈sup〉2〈/sup〉 g〈sup〉−1〈/sup〉, respectively, but the adsorption capacity of Cd increased to 22.37 mg g〈sup〉−1〈/sup〉 and 26.43 mg g〈sup〉−1〈/sup〉, respectively, which was more than three times that of KBC (7.02 mg g〈sup〉−1〈/sup〉). The interaction between nZVI/nHIO and Cd was enhanced by the complexation of surface functional groups, but the coupling effects were different. The coupling mechanism of Cd on nZVI@KBC was complexation - reduction. Cd was partly reduced in the removal process. While for nHIO@KBC, the existence of Fe (III) on the surface of biochar increased the number and species of oxygen-containing functional groups and enhanced complexation. The existence of synergistic mechanism will provide theoretical basis for the preparation of high efficient nanocomposites and expand the application of nanomaterials in the field of environment.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S004565351832335X-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Catherine C. Beaucham, Diana Ceballos, Charles Mueller, Elena Page, Mark J. La Guardia〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Flame retardants have been associated with endocrine disorders, thyroid disruption, reproductive toxicity, and immunological interference. Through dismantling and recycling electronics and electric products, flame retardants can be released into the air and settle on work surfaces which may lead to dermal exposure. Hand wipe sampling is commonly used to evaluate dermal exposure. This study assesses the removal efficiency of wipes on the hands of recycling employees, and to compare the efficacy of two common surface wipe sampling materials. We used three sequential hand wipes and quantified the percentage of flame retardants that was removed by each hand wipe in the sequence. Two common wipe materials (gauze and twill) were used to compare the ability to remove flame retardants. The wipes were collected from 12 employees at a U.S. electronics recycling facility immediately at the end of their shift, prior to washing their hands. Results show that although the first wipe removed the highest median percent of the sum of the three wipes for most flame retardants, there was a wide range of the percentages of total individual flame retardants removed by both gauze (4%–98%) or twill hand wipe (1%–89%). Approximately half of the flame retardants a high percentage (〉50%) removed by the second and third wipes. This suggests that a single wipe is not sufficient to characterize the extent of dermal contamination. The average of the total amount of flame retardants removed by twill wipes was greater than the average using gauze, but the difference was not statistically significant.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Emna Fourati, Katarina Vogel-Mikuš, Taoufik Bettaieb, Anja Kavčič, Mitja Kelemen, Primož Vavpetič, Primož Pelicon, Chedly Abdelly, Tahar Ghnaya〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉〈em〉Sesuvium portulacastrum,〈/em〉 a halophyte with high tolerance to heavy metals like Cd, Pb and Ni is considered for phytoremediation of metal contaminated saline soils. The tolerance to a selected metal ion could, by hypothesis, be stimulated through 〈em〉in vitro〈/em〉 adaptation and regeneration of the plant. Seedlings obtained by 〈em〉in vitro〈/em〉 micro-propagation, were exposed to 0, 25 and 50 μM Ni, as NiCl〈sub〉2〈/sub〉, in agar-based medium for 30 days. Growth parameters, plant water content, the concentration of photosynthetic pigments, proline and malondialdehyde (MDA) concentrations were determined. Nickel and nutrients distribution in leaves was studied by micro-Proton-Induced-X-ray-Emission (μ-PIXE). The results showed that Ni was mainly accumulated in vascular bundles, next in water storage tissues and chlorenchyma. Ni concentrations in chlorenchyma increased with increasing Ni in culturing medium, in direct relation to decrease of photosynthetic pigments and increase of oxidative stress. As compared to control plants, Ni induced substantial increase in MDA and proline accumulation. Plants exposed to 50 μM Ni accumulated up to 650 μg g〈sup〉−1〈/sup〉 of Ni in the shoots, exhibiting chlorosis and necrosis and a drastically reduced plant growth. Perturbations in uptake and distribution of nutrients were observed, inducing mineral deficiency, probably through membrane leakage. The mineral nutrient disturbances induced by Ni could be highly implicated in the restriction of 〈em〉S. portulacastrum〈/em〉 development under the acute 50 μM Ni level.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Hoi-Shing Lo, Chun-Yuen Wong, Nora Fung-Yee Tam, Siu-Gin Cheung〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The spatial distribution, composition and source of hydrophobic organic compounds (HOCs) including polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorinated pesticides (OCPs) of the sedimentary microplastics (0.25–5 mm) in Hong Kong were investigated. The concentration of ΣPAHs ranged between 70.8 and 1509 ng g〈sup〉−1〈/sup〉 with inter-site differences although the regional difference was insignificant, indicating localised pyrolytic and petrogenic input of PAHs. The concentration of ΣPCBs (13–1083 ng g〈sup〉−1〈/sup〉) varied with both study sites and regions with higher concentrations obtained in the western waters, possibly due to the input from Pearl River. Significantly higher concentrations of OCPs on eastern shores highlighted fishing and aquaculture activities in South China Sea a potential major source of OCPs. DDT and its metabolites (DDX, ranged from 1.96 to 626 ng g〈sup〉−1〈/sup〉) were the dominant forms of OCPs (45%–80%). Since most of the DDX existed as DDT, this suggested that there was a fresh input of DDT into the microplastics. As microplastics and HOCs cannot be removed effectively from the environment, reduction of potential ecotoxicological risks should rely on minimizing the use of plastics and HOCs.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Nguyen Thanh-Nho, Cyril Marchand, Emilie Strady, Truong-Van Vinh, Tran-Thi Nhu-Trang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Mangrove sediments act as natural biogeochemical reactors, modifying metals partitioning after their deposition. The objectives of the present study were: to determine distribution and partitioning of metals (Fe, Mn, Ni, Cr, Cu, Co and As) in sediments and pore-waters of Can Gio Mangrove; and to assess their ecological risks based on Risk Assessment Code. Three cores were collected within a mudflat, beneath 〈em〉Avicennia alba〈/em〉 and 〈em〉Rhizophora apiculata〈/em〉 stands. We suggest that most metals had a natural origin, being deposited in the mangrove mainly as oxyhydroxides derived from the upstream lateritic soils. This hypothesis could be supported by the high proportion of metals in the residual fraction (mean values (%): 71.9, 30.7, 80.7, 80.9, 67.9, 53.4 and 66.5 for Fe, Mn, Ni, Cr, Cu, Co, and As respectively, in the mudflat). The enrichment of mangrove-derived organic matter from the mudflat to the 〈em〉Rhizophora〈/em〉 stand (i.e. up to 4.6% of TOC) played a key role in controlling metals partitioning. We suggest that dissolution of Fe and Mn oxyhydroxides in reducing condition during decomposition of organic matter may be a major source of dissolved metals in pore-waters. Only Mn exhibited a potential high risk to the ecosystem. Most metals stocks in the sediments were higher in the 〈em〉Avicennia〈/em〉 stand than the 〈em〉Rhizophora〈/em〉 stand, possibly because of enhanced dissolution of metal bearing phases beneath later one. In a context of enhanced mangrove forests destruction, this study provides insights on the effects of perturbation and oxidation of sediments on metal release to the environment.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Yu Cao, Hui Liu, Junyao Sun, Yang Liu, Hong Sheng Jiang, Wei Wang, Wei Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Submerged macrophytes are considered the main primary producers in shallow lakes. Recently, they have experienced a decline due to increasing environmental impacts, e.g., excessive heavy metal loads. Compared to extensive studies on vegetative growth, reports on effects of heavy metals on propagule germination and reproduction remain scarce. In this study, three experiments were conducted to investigate the effects of cadmium (Cd) on the propagule germination and sexual reproduction of submerged macrophytes. In Experiment I, six Cd concentrations were used (0, 0.05, 0.5, 1, 2.5, and 5 mg L〈sup〉−1〈/sup〉), with seed germination found to be marginally affected by Cd treatment. In Experiment II, Cd exposure (5 d) at the six Cd concentrations was performed 15, 30, 60, 90, and 120 d prior to the designated germination date for turions/tubers. The 〈em〉Vallisneria spinulosa〈/em〉 tubers did not germinate at ≥ 2.5 mg Cd L〈sup〉−1〈/sup〉 when exposed to Cd 90 and 120 d prior to germination, whereas the 〈em〉Potamogeton crispus〈/em〉 turions remained viable but with a low germination rate at ≥ 2.5 mg Cd L〈sup〉−1〈/sup〉. In Experiment III, with an increase from 0 to 0.5 Cd mg L〈sup〉−1〈/sup〉, the fruit weight of 〈em〉Ottelia alismoides〈/em〉 and 〈em〉V. spinulosa〈/em〉 decreased, whereas the fruit number increased for 〈em〉O. alismoides〈/em〉 but not for 〈em〉V. spinulosa.〈/em〉 Furthermore, the phenology of sexual reproduction for both species advanced under Cd exposure. In summary, Cd exposure affected the germination of asexual propagules and sexual reproduction of submerged macrophytes, with seeds found to be tolerant of Cd treatment up to 5 mg L〈sup〉−1〈/sup〉.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518323786-fx1.jpg" width="386" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): T.H. Lee, D.C.W. Tsang, W.H. Chen, F. Verpoort, Y.T. Sheu, C.M. Kao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Emulsified polycolloid substrate (EPS) was developed and applied in situ to form a biobarrier for the containment and enhanced bioremediation of a petroleum-hydrocarbon plume. EPS had a negative zeta potential (−35.7 mv), which promoted its even distribution after injection. Batch and column experiments were performed to evaluate the effectiveness of EPS on toluene containment and biodegradation. The EPS-to-water partition coefficient for toluene (target compound) was 943. Thus, toluene had a significant sorption affinity to EPS, which caused reduced toluene concentration in water phase in the EPS/water system. Groundwater containing toluene (18 mg/L) was pumped into the three-column system at a flow rate of 0.28 mL/min, while EPS was injected into the second column to form a biobarrier. A significant reduction of toluene concentration to 0.1 mg/L was observed immediately after EPS injection. This indicates that EPS could effectively contain toluene plume and prevent its further migration to farther downgradient zone. Approximately 99% of toluene was removed after 296 PVs of operation via sorption, natural attenuation, and EPS-enhanced biodegradation. Increase in total organic carbon and bacteria were also observed after EPS supplement. Supplement of EPS resulted in a growth of petroleum-hydrocarbon degrading bacteria, which enhanced the toluene biodegradation.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Yong-Por Ong, Li-Ngee Ho, Soon-An Ong, Johar Banjuraizah, Abdul Haqi Ibrahim, Sin-Li Lee, Noradiba Nordin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Photocatalytic fuel cell (PFC) is considered as a sustainable green technology which could degrade organic pollutant and generate electricity simultaneously. A synergistic double-sided ZnO/BaTiO〈sub〉3〈/sub〉 loaded carbon plate heterojunction photoanode was fabricated in different ratios by using simple ultrasonication and mixed-annealed method. The double-sided design of photoanode allowed the lights irradiated at both sides of the photoanode. The ferroelectricity fabricated photoanode was applied in a membraneless PFC with platinum-loaded carbon as the cathode. Results revealed that the photoanode with 1:1 ratio of BaTiO〈sub〉3〈/sub〉 and ZnO exhibited a superior photocatalytic activity among all the photoanodes prepared in this study. The heterojunction of this photoanode was able to achieve up to a removal efficiency of 93.67% with a maximum power density of 0.5284 μW cm〈sup〉−2〈/sup〉 in 10 mg L〈sup〉−1〈/sup〉 of Reactive Red 120 (RR120) without any supporting electrolyte. This photoanode was able to maintain at high performance after recycling 3 times. Overloading of ZnO above 50% on BaTiO〈sub〉3〈/sub〉 could lead to deterioration of the performance of PFC due to the charge defects and light trapping ability. The interactions, interesting polarizations of the photocatalysts and proposed mechanism of the n-n type heterojunction in the photoanode of ZnO/BaTiO〈sub〉3〈/sub〉 was also discussed.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518323269-fx1.jpg" width="381" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Victor Augusto Araújo de Freitas, Samuel Moura Breder, Flávia Paulucci Cianga Silvas, Patrícia Radino Rouse, Luiz Carlos Alves de Oliveira〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The global demand for iron ore with high iron contents to supply the steel industry is associated, in most countries, with the generation of tailings from mineral processing. The chemical compositions of iron ore tailings (basically Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 and SiO〈sub〉2〈/sub〉) make them an excellent candidate as a catalyst for advanced oxidation processes (AOPs), especially the Fenton process and its derivatives. Therefore, this paper aimed to transform iron ore tailings from tailing dams into catalysts able to activate H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 for the purpose of treating, in a continuous flow, effluents contaminated with organic dyes, employing methylene blue as a model molecule. The mineralogical characteristics of 〈em〉in natura〈/em〉 tailings, such as the associations between iron oxides and quartz and the particle sizes of iron oxides, are favourable points for their transformation into catalysts by Fenton-like processes. Different pellet geometries and binding agents were evaluated to optimize the dye removal. Pellet pretreatment in a CH〈sub〉4〈/sub〉 atmosphere at 550 °C for 2 h with 10% bentonite as a binding agent (RCSP sample) resulted in the removal of approximately 80% of dye. Kinetic removal data show the good stability of the catalyst in the flow system. Significant catalytic activity loss was not observed after four runs, and data from TG-MS indicate that there is a synergetic mechanism between the adsorption, radical attack and desorption processes of the substrate on the catalyst surface.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518323749-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Naima A. Khan, Michael D. Johnson, James D. Kubicki, F. Omar Holguin, Barry Dungan, Kenneth C. Carroll〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Enhanced reactivity of aqueous ozone (O〈sub〉3〈/sub〉) with hydroxypropyl-β-cyclodextrin (HPβCD) and its impact on relative reactivity of O〈sub〉3〈/sub〉 with contaminants were evaluated herein. Oxidation kinetics of 1,4-dioxane, trichloroethylene (TCE), and 1,1,1-trichloroethane (TCA) using O〈sub〉3〈/sub〉 in single and multiple contaminant systems, with and without HPβCD, were quantified. 1,4-Dioxane decay rate constants for O〈sub〉3〈/sub〉 in the presence of HPβCD increased compared to those without HPβCD. Density functional theory molecular modeling confirmed that formation of ternary complexes with HPβCD, O〈sub〉3〈/sub〉, and contaminant increased reactivity by increasing reactant proximity and through additional reactivity within the HPβCD cavity. In the presence of chlorinated co-contaminants, the oxidation rate constant of 1,4-dioxane was enhanced. Use of HPβCD enabled O〈sub〉3〈/sub〉 reactivity within the HPβCD cavity and enhanced 1,4-dioxane treatment rates without inhibition in the presence of TCE, TCA, and radical scavengers including NaCl and bicarbonate. Micro-environmental chemistry within HPβCD inclusion cavities mediated contaminant oxidation reactions with increased reaction specificity.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518323075-fx1.jpg" width="273" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Jing Xie, Xu Duan, Leiyu Feng, Yuanyuan Yan, Feng Wang, Haiqing Dong, Renyong Jia, Qi Zhou〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Extensive studies on anaerobic fermentation of waste activated sludge (WAS) for volatile fatty acids (VFAs) production focused on the effects of operating parameters and pretreatment methods, and little information is available for those of organic pollutants which were absorbed on sludge. The influence of sulfadiazine (SDZ), a typical antibiotic pollutant in WAS, on VFAs production during anaerobic fermentation was investigated in this study. The accumulation of VFAs was remarkably affected in the presence of SDZ. When the content of SDZ was 50 mg per kilogram dry sludge the concentration of VFAs from sludge was 2032.8 mg COD/L, much higher than that of control (1540.2 mg COD/L). Mechanism investigation revealed that the content of extracellular polymeric substances (EPS) from sludge was increased due to the presence of SDZ, which provided more substrates, 〈em〉i.e.〈/em〉, protein and carbohydrate, and created a favorable environment for anaerobes. The hydrolysis and acidification of WAS were stimulated by SDZ, and the functional microorganisms were advantageous to VFAs production. The activities of protease, α-glucosidase and acetate kinase were promoted when SDZ occurred, which were beneficial for hydrolysis and acidification. The effect of SDZ on pure strains further confirmed that the formation of VFAs during anaerobic fermentation was stimulated by SDZ.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518323373-fx1.jpg" width="428" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Weixin Jing, Lang Lang, Zigen Lin, Na Liu, Lan Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Experiments were carried out to investigate the bioaccumulation and elimination of cadmium (Cd) in tissues (kidney, gills, digestive gland, mantle, visceral mass, foot, adductor muscle and hemolymph) from the freshwater mussel, 〈em〉Anodonta woodiana〈/em〉. The mussels were exposed to subchronic Cd at concentrations of 0.168 and 0.675 mg L〈sup〉−1〈/sup〉 for 28 d of bioaccumulation and 28 d of elimination. During the bioaccumulation phase, Cd bioaccumulations increased in all tissues. The highest bioaccumulation of Cd was found in the kidney. The second-highest and third-highest bioaccumulations of Cd were found in the digestive gland and gills, respectively. The Cd bioaccumulations in the tissues of 〈em〉A. woodiana〈/em〉 increased with exposure time and concentration, except for hemolymph, which reached the highest value on d 14. The bioaccumulation factors (BCFs) increased with exposure time, but an inverse relationship was observed between BCFs and exposure concentration. During the elimination phase, the visceral mass showed the highest Cd elimination rate. In the kidney, digestive gland and gills, the elimination rates almost reached 40%, but their concentrations were still higher than in other tissues. Thus, we concluded that the kidney, gills and digestive gland of 〈em〉A. woodiana〈/em〉 are target tissues for subchronic Cd toxicity.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 20 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 297〈/p〉 〈p〉Author(s): Akanksha Joshi, Shubra Lalwani, Gurmeet Singh, Raj Kishore Sharma〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The present study elaborates facile approach to generate active sites in cashew nut shaped silica (SiO〈sub〉2〈/sub〉). These active sites are attributed to the high concentration of oxygen vacancies and bimodal mesoporosity in silica owing to etching and calcination treatment. In the etched calcined silica (ECS), mesopores act as buffered spaces, whereas, OVs provide high carrier/donor density (3 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mrow〉〈mo〉×〈/mo〉〈msup〉〈mrow〉〈mn〉10〈/mn〉〈/mrow〉〈mrow〉〈mn〉24〈/mn〉〈/mrow〉〈/msup〉〈/mrow〉〈/math〉cm〈sup〉−3〈/sup〉). High density of carriers/donor reduces the distance between active sites (2.5 nm) further enhancing the rate of electron transfer. Consequent to the unique combination of OVs and bimodal mesoporosity, ECS exhibits high electrochemically accessible surface area (3170 m〈sup〉2〈/sup〉 g〈sup〉−1〈/sup〉) and excellent charge storage in ECS||ECS cell (∼337 F g〈sup〉−1〈/sup〉 at 1 A g〈sup〉−1〈/sup〉). In addition, the symmetric cell (ECS||ECS) delivers maximum energy density of 46.86 Wh Kg〈sup〉−1〈/sup〉 at power density of 537.59 W kg〈sup〉−1〈/sup〉 with respectable capacitance retention (111% after 10,000 cycles). Remarkably, the solid state flexible device unveiled energy density of 2.16 Wh Kg〈sup〉−1〈/sup〉 at 166.05 W kg〈sup〉−1〈/sup〉 even under the bent state retaining 165% of its capacitance up till 3000 cycles. This work essentially highlights the synergism between mesoporosity and oxygen vacancies on the charge storage characteristics of silica.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Synergistic contribution of bimodal mesopores and oxygen vacancies in silica for excellent supercapacitive performance.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0013468618327312-fx1.jpg" width="250" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 297〈/p〉 〈p〉Author(s): Antonio Doménech-Carbó, María Teresa Doménech-Carbó, Amparo Castelló-Palacios, Vicent Guerola-Blay, Eva Pérez-Marín〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The voltammetry of immobilized particles (VIMP) methodology was applied to discriminate the oil painting production of a series of seven painters/workshops that worked in Valencia (Spain) between ca. 1530 and ca. 1650. When submicrosamples used for cross-section FESEM/EDX analysis were attached to graphite electrodes in contact with aqueous acetate buffer, well-defined responses were obtained. The reductive processes of lead pigments (lead white and lead-tin yellow) overlapped those associated to the lead soaps and other species resulting from the pigment-oil binder interaction in the sample. Such responses, which are theoretically modeled, were sensitive to changes in paint type and dose and thus provided a painter/workshop-characteristic voltammetric response defining a usable electrochemical fingerprint for authorship assessments.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0013468618326963-fx1.jpg" width="157" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 297〈/p〉 〈p〉Author(s): Aria Kahyarian, Srdjan Nesic〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In the context of H〈sub〉2〈/sub〉S corrosion of mild steel, the direct electrochemical reduction of H〈sub〉2〈/sub〉S is currently believed to be the main contribution of this species to cathodic currents. That is perhaps due to the distinct behavior of the cathodic polarization curves observed in the presence of H〈sub〉2〈/sub〉S, as compared to those obtained in strong acids solutions or in the presence of other weak acids such as carboxylic acids and carbonic acid. In the presence of aqueous H〈sub〉2〈/sub〉S, the cathodic polarization curves show a “double wave” shape, that is widely considered to be the result of the direct reduction of H〈sub〉2〈/sub〉S. In the present study, the mechanism of H〈sub〉2〈/sub〉S corrosion of mild steel is theoretically investigated with the focus on the buffering ability of H〈sub〉2〈/sub〉S. It is shown that all characteristic behaviors of cathodic currents that were previously associated with the direct reduction of H〈sub〉2〈/sub〉S, including the “double wave”, can be fully explained in terms of the H〈sub〉2〈/sub〉S dissociation reaction and its buffering effect. In order to further evaluate this mechanistic argument, a comprehensive mathematical model for the H〈sub〉2〈/sub〉S system was developed and the calculated cathodic polarization curves were compared with the existing experimental data in the open literature. The results showed that the model, built with H〈sup〉+〈/sup〉 reduction as the sole cathodic reaction, is able to reasonably capture all characteristic behavior of cathodic currents, further supporting this mechanistic argument.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 20 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 297〈/p〉 〈p〉Author(s): Yaohui Liang, Nan Li, Fengyan Li, Zhiwei Xu, Yanli Hu, Miaolei Jing, Kunyue Teng, Xuemei Yan, Jie Shi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Further modification of carbon and transition metal composites has become a hot spot in the preparation of anode materials for lithium ion battery, including various morphologies, nitrogen doping and porous introduction. However, the synergistic effect of specific surface area and nitrogen doping content of composite materials on the electrochemical performance as anode materials for lithium ion batteries has not been revealed. In this paper, the carbon nanofibers loaded with titanium dioxide are fabricated via electrospinning method followed by calcination process with simple addition admixture of diisopropyl azodiformate in precursor solution. The pores are introduced into the composite with controllable nitrogen doping and surface area simultaneously. The specific capacity of titanium dioxide @carbon nanofibers has been increased from 192.2 mAh g〈sup〉−1〈/sup〉 to 336 mAh g〈sup〉−1〈/sup〉 due to the increased nitrogen content of the composite from 7.18% to 10.21%, and elevated specific surface area from 67.23 to 111.15 m〈sup〉2〈/sup〉 g〈sup〉−1〈/sup〉, which can endow the composite superior conductivity and more active sites. The capacity contribution of the total specific capacity has decreased from 60.8% to 44.7% compared with original sample, proving that increasing diffusion controlled Faradaic Li-ion insertion origins from nitrogen doping.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0013468618327105-fx1.jpg" width="456" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 297〈/p〉 〈p〉Author(s): Yuebin Yang, Hui Xu, Shanxing Wang, Yuanfu Deng, Xianying Qin, Xusong Qin, Guohua Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Li-ion batteries have held a dominant position in the energy storage area for decades. However, due to the limitation of its chemistry, the energy density of Li-ion batteries is limited to ∼300 W h kg〈sup〉−1〈/sup〉. In recent years, more attention has been paid to the Li-S batteries that are environmentally friendly, cost-effective and high energy density (theoretical value of cathode: ∼2600 W h kg〈sup〉−1〈/sup〉). In this study, carbonized polydopamine (C-PDA)-coated hollow carbon nanofibers (CNFs) with TiO〈sub〉2〈/sub〉 nanoparticles interspersed in the void space between the CNF skeleton and carbon coating layer were subtly designed. The C-PDA/TiO〈sub〉2〈/sub〉/CNF composite (CTC) was integrated with the commercial separator as a polysulfide filter to achieve high-performance Li-S batteries. It is reveals that the CTC coating layer could effectively filter and reactivate the dissolved polysulfides to achieve a stabilized sulfur-based cathode. The Li-S battery assembled by this integrated separator and the regular cathode (sulfur/Ketjen black) with 72.7 wt% of sulfur achieved a high specific capacity and low decay rate (632.5 mAh g〈sup〉−1〈/sup〉 at the first cycle and 0.06% per cycle) at 2.0C for 500 cycles. These good results indicate that the C-PDA/TiO〈sub〉2〈/sub〉/CNF-modified separator could be a promising separator candidate for high performance Li-S batteries.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 298〈/p〉 〈p〉Author(s): Lewis C. Yule, Cameron L. Bentley, Geoff West, Barbara A. Shollock, Patrick R. Unwin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The development of tools that can probe corrosion related phenomena at the (sub)microscale is recognized to be increasingly important in order to understand the surface structural factors (grain orientation, inclusions 〈em〉etc.〈/em〉) that control the (electro)chemical stability (corrosion susceptibility, pitting, passivity 〈em〉etc.〈/em〉) of metal surfaces. Herein we consider the application of scanning electrochemical cell microscopy (SECCM), a relatively new member of the electrochemical droplet cell (EDC) family, for corrosion research and demonstrate the power of this technique for resolving structure and activity at the (sub)microscale. Hundreds of spatially-resolved (2 μm droplet size) potentiodynamic polarization experiments have been carried out on the several hours timescale and correlated to complementary structural information from electron backscatter diffraction (EBSD) and energy dispersive x-ray spectroscopy (EDS) in order to determine the effect of grain orientation and inclusions on electrochemical processes at low carbon steel in neutral solution (10 mM KNO〈sub〉3〈/sub〉). Through this approach, it has been shown unequivocally that for the low index planes, anodic currents in the passive region (an indicator of corrosion susceptibility) are greatest on (101) planes compared to (100) and (111) planes. Furthermore, individual sub-micron MnS inclusions have been probed and shown to undergo active dissolution followed by rapid repassivation. This study demonstrates the high versatility of SECCM and the considerable potential of this technique for addressing structure-activity problems in corrosion and electromaterials science.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 296〈/p〉 〈p〉Author(s): Vera Smulders, Nina Simic, Adriano S.O. Gomes, Bastian Mei, Guido Mul〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In electrochemical production of sodium chlorate from brine solutions, an intriguing function of sodium (di)chromate is to inhibit cathodic reduction of oxychlorides, while maintaining effective reduction of water to form hydrogen. Using an electrochemical Quartz Crystal Microbalance (eQCM) and a Rotating Ring Disk Electrode (RRDE; Au disk, Pt ring), we analyzed the deposition of reduced Cr-species formed from reduction of Cr〈sup〉VI〈/sup〉O〈sub〉4〈/sub〉〈sup〉2−〈/sup〉 on Au electrodes. Generally, the current induced by reduction of Cr〈sup〉VI〈/sup〉O〈sub〉4〈/sub〉〈sup〉2−〈/sup〉 is significantly larger than the accumulated amount of weight deposited on the Au electrode. Deconvolution of the reductive peak reveals two processes that can be differentiated by varying rotation speed. We therefore propose soluble Cr〈sup〉V〈/sup〉O〈sub〉4〈/sub〉〈sup〉3−〈/sup〉 is formed by reduction of Cr〈sup〉VI〈/sup〉O〈sub〉4〈/sub〉〈sup〉2−〈/sup〉, followed by consecutive reduction of Cr〈sup〉V〈/sup〉O〈sub〉4〈/sub〉〈sup〉3−〈/sup〉 to primarily soluble Cr〈sup〉III〈/sup〉(OH)〈sub〉4〈/sub〉〈sup〉-〈/sup〉. Simultaneously, reduction of Cr〈sup〉V〈/sup〉O〈sub〉4〈/sub〉〈sup〉3−〈/sup〉 also leads to the formation of a monolayer of Cr〈sup〉III〈/sup〉(hydr)oxide. This monolayer significantly inhibits the further reduction of Cr〈sup〉VI〈/sup〉O〈sub〉4〈/sub〉〈sup〉2−〈/sup〉, but allows the film to reach a maximum thickness of approximately 1.85 nm by reduction of surface adsorbed Cr〈sup〉V〈/sup〉O〈sub〉4〈/sub〉〈sup〉3−〈/sup〉 and/or de-hydroxylation of Cr〈sup〉III〈/sup〉(OH)〈sub〉4〈/sub〉〈sup〉-〈/sup〉. The observation that limitation of film growth is due to film-induced inhibition of reduction of Cr〈sup〉VI〈/sup〉O〈sub〉4〈/sub〉〈sup〉2−〈/sup〉, and significant solubility of Cr〈sup〉III〈/sup〉(OH)〈sub〉3〈/sub〉 in the form of Cr〈sup〉III〈/sup〉(OH)〈sub〉4〈/sub〉〈sup〉-〈/sup〉, will aid in the search of a non-toxic chrome-free alternative for inhibition of cathodic reduction of oxychlorides and selective hydrogen evolution in the chlorate process.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Redox chemistry leading to deposition of Cr〈sup〉III〈/sup〉O〈sub〉x〈/sub〉 from Na〈sub〉2〈/sub〉Cr〈sub〉2〈/sub〉O〈sub〉7〈/sub〉 on a Au electrode.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0013468618325295-fx1.jpg" width="268" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Rut Sanchis, Ana Dejoz, Isabel Vázquez, Enrique Vilarrasa-García, José Jiménez-Jiménez, Enrique Rodríguez-Castellón, José M. López Nieto, Benjamín Solsona〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Ferric chloride solutions are used as coagulants or flocculants in water treatment operations for human consumption. This treatment produces large amounts of clay-type solids formed mainly of montmorillonite with iron oxides and humic substances. This ferric sludge can be used as an efficient catalyst for the removal of volatile organic compounds (VOCs) by total oxidation. This waste isolated in the purification process has been activated by calcinations in air, characterized by several physicochemical techniques and employed as a catalyst for the removal by total oxidation of representative VOCs: toluene, propane and mixtures of toluene/propane with or without water. This ferric sludge has shown a catalytic activity one order of magnitude higher than that of a commercial iron oxide. This high activity has been related to the composition of the sludge (as it contains active metal oxides such as oxides of iron and manganese) and to the porous structure (leading to a reasonably high surface area). Moreover, it can be also used as a support for platinum, showing comparable (or even higher) catalytic activity than a similar platinum catalyst supported on conventional γ-alumina. This work presents a double environmental perspective since the material employed as a catalyst is a waste sludge and the catalytic reaction studied deals about the elimination of pollutants.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518323245-fx1.jpg" width="281" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Xiao-Qiu Lin, Zhi-Ling Li, Bin Liang, Jun Nan, Ai-Jie Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Improving anode configuration with polymer or nanomaterial modification is promising for enhancing microbial fuel cell performance. However, how anode modification affects biofilm development and electrogenic function remains poorly understood. In this study, the carbon cloth anode modified with polyaniline and reduced graphene oxide was successfully fabricated which obtained the highest power output. Accelerated electrogenic biofilm formation and the better electrogenic bacterial colonization based on the superior material properties (preferable electrochemical characteristics, the film-like structure and the more activated sites) were observed with the 〈em〉in situ〈/em〉 biofilm development monitoring. The acclimation time was 2.4 times shorter with graphene and polyaniline modified anode than the bare one when inoculated with wastewater. Biofilm structure and function analysis show that 〈em〉Geobacter〈/em〉 is the most predominant with the abundance as high as 81.4%, and meanwhile, electrogenesis related outer-surface octaheme c-type cytochrome 〈em〉omc〈/em〉Z is highly expressed in the modified anode. The anode modified with graphene and polyaniline favors 〈em〉Geobacter〈/em〉 colonization, accelerates electrogenic biofilm formation and improves 〈em〉omc〈/em〉Z expression level, eventually leading to the improved performance of microbial fuel cell. The study for the first time reveals the impacts on biofilm development and microbial function by anode modification, which will better guide the potential application of microbial fuel cell for wastewater recovery.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518323191-fx1.jpg" width="245" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Olushola M. Awoyemi, Naveen Kumar, Cassandra Schmitt, Seenivasan Subbiah, Jordan Crago〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Pyrethroids are potent neurotoxicants that may elicit multiple pathways of toxicity in non-target organisms. Comparative studies on the mechanistic and developmental effects of types I and II pyrethroids against non-target aquatic species are limited. This study assessed the effects of the two pyrethroid types against embryo-larval zebrafish (〈em〉Danio rerio〈/em〉) at environmentally relevant and laboratory concentrations. Zebrafish embryos were exposed to type-I (permethrin, bifenthrin) and type-II (deltamethrin, λ-cyhalothrin, fenvalerate, esfenvalerate) pyrethroids at 1000, 10, 0.1, 0.01, 0.0 μg/L, starting at 5-h post-fertilization (hpf) through 5-d post-fertilization (dpf) under static exposure conditions. Swimming behavior (distance traveled and velocity) was assessed at 5-dpf. The relative expression of Nrf2a, GST, Casp-9 and p53 mRNA transcripts, carboxyl esterase (CES) activity and total reactive oxygen species (ROS) were measured. The stability of the pyrethroids across 5 days was analyzed. Bifenthrin-(10 μg/L) and esfenvalerate-(1000 μg/L) significantly (p 〈 0.05) reduced total distance traveled by larvae while 1000 μg/L deltamethrin and λ-cyhalothrin were lethal causing body axis curvature and pericardial edema. At environmentally relevant concentrations-(μg/L) compared to control, permethrin-(0.122) upregulated Nrf2a and Casp-9 expressions while λ-cyhalothrin-(0.053) downregulated Nrf2a and fenvalerate-0.037 downregulated GST. At laboratory concentrations-(μg/L), permethrin-(1000) upregulated Nrf2a, Casp-9 and p53 expressions, bifenthrin-(10) upregulated Casp-9 while fenvalerate-(0.1) and esfenvalerate-(1000) downregulated GST. There was concentration dependent increase in CES activity which correlated positively with total ROS. Pyrethroid concentrations decreased significantly by day 5. This study showed disparity in the mechanistic effects across the pyrethroids types and their instability in aqueous media may underestimate toxicity against non-target aquatic species when exposed in their natural environment.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518323488-fx1.jpg" width="300" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Inácio Abreu Pestana, Lucas Silva Azevedo, Wanderley Rodrigues Bastos, Cristina Maria Magalhães de Souza〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The increase in global demand for electric energy is reflected in plans to construct numerous hydroelectric dams in South America that can cause chronic ecological impacts if not built and managed correctly. One of the main impacts generated by hydropower dams is the accumulation of Hg chemical species in their reservoir compartments and the downstream transport of these contaminants. Hg circulation in these environments has been studied for 27 years and this review brings a synthesis of the dynamics that are now well established, so that future studies can focus on gaps and inconsistent results in the literature. The topics cover the methylation process of Hg, its transfer along the trophic chain and the impacts downstream from dams. In addition, meta-analyses are used to propose regression models that explain Hg dispersion in environmental compartments of reservoirs, using as predictors morphological, spatial and temporal aspects of these environments.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Richa Soni, Dericks Praise Shukla〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A zeolite-reduced graphene oxide (ZrGO) based composite was synthesized to remove arsenic from water. To make a low-cost adsorbent, zeolite was synthesized using an inexpensive waste material; fly ash, which was further used to produce the ZrGO composite. Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and Raman spectra were used to characterize the morphology and surface composition of the synthesized materials. Synthesized materials: zeolite, rGO and ZrGO were evaluated as an adsorbent to remove arsenic from water. The results indicated that all three were able to adsorb arsenic from water but the removal efficiency of ZrGO was the best as it was able to bring down the arsenic concentration within the WHO permissible limits. The maximum adsorption capacity for 100 μg/L of initial arsenic concentration was found to be 49.23 μg/g. Results indicate that pseudo second order kinetics describes the arsenic adsorption on ZrGO. Adsorption isotherm study for ZrGO shows best fit for Redlich-Peterson model of adsorption.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518323105-egi10SN394D1QS.jpg" width="500" alt="Image 103941" title="Image 103941"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Elizabeth A. Gibson, Heather M. Stapleton, Lehyla Calero, Darrell Holmes, Kimberly Burke, Rodney Martinez, Boris Cortes, Amy Nematollahi, David Evans, Kim A. Anderson, Julie B. Herbstman〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈h6〉Background〈/h6〉 〈p〉Humans are ubiquitously exposed to flame retardants, including organophosphate esters (OPEs), through direct contact with consumer products or exposure through household dust. Children are at increased risk because of their proximity to dust, hand-to-mouth activity, and the importance of childhood as a critical period in neurodevelopment.〈/p〉 〈/div〉 〈div〉 〈h6〉Objectives〈/h6〉 〈p〉To quantify differences in exposure levels between mothers and children (three to six years of age), we analyzed urinary metabolites of OPEs. We additionally assessed the ability of silicone wristbands (measuring ambient exposure) to predict urinary metabolite concentrations.〈/p〉 〈/div〉 〈div〉 〈h6〉Methods〈/h6〉 〈p〉We selected 32 mother and child dyads from an existing cohort. Participants provided baseline urine samples and wore wristbands for one week. After the first week, they returned their wristbands and provided a second urine sample. During the second week, participants wore a second wristband that they returned at the end of week two with a third and final urine sample.〈/p〉 〈/div〉 〈div〉 〈h6〉Results〈/h6〉 〈p〉We found significantly higher levels of bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) (p 〈 0.001) and lower levels of bis(1-chloro-2-isopropyl) 1-hydroxy-2-propyl phosphate (BCIPHIPP) (p 〈 0.001) in children's urine samples compared to mothers' samples at baseline. We found that triphenylphosphate (TPHP), tris(1,3-dichloroisopropyl) phosphate (TDCIPP), and tris(1-chloro-2-propyl) phosphate (TCIPP) measured in wristbands predicted their respective metabolite levels in urine.〈/p〉 〈/div〉 〈div〉 〈h6〉Conclusion〈/h6〉 〈p〉Children had higher levels than mothers for two of six flame retardant metabolites measured in urine. Generally, wristband measurements positively predicted internal dose. As little is known about the health effects of OPEs on child development, future research is needed to determine the impact of differential exposure.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Bon-Wun Gu, Seung-Hee Hong, Chang-Gu Lee, Seong-Jik Park〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The aim of this study was to assess the feasibility of using bentonite, illite, and zeolite as capping materials to interrupt the release of and sequestrate carbon, nitrogen, and phosphorus from contaminated sediments. Their efficiency was assessed in batch isotherm, column incubation experiments, and nitrogen and phosphorus extraction from the capping materials and sediments. All capping materials contributed to the reduction of dissolved oxygen depletion and chemical oxygen demand in overlying water. Zeolite showed a high adsorption capacity for NH〈sub〉4〈/sub〉-N; the zeolite cap produced the lowest NH〈sub〉4〈/sub〉-N flux constituting the highest percentage of total nitrogen in the overlying water. Significant changes in water conditions, such as an increased pH (〉8) and lowered oxidation reduction potential (〈−80 mV) were observed when a bentonite cap was used. Illite showed high capping efficiency (〉130%) for both PO〈sub〉4〈/sub〉-P and total phosphorus, and phosphorus was adsorbed mainly as the high residual-P fraction (≈90%) in its strongest adsorbed form. The results of this study indicate that illite has potential for use as an agent to deactivate phosphorus in lake eutrophication control techniques.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518323439-fx1.jpg" width="402" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Silvia Quadroni, Roberta Bettinetti〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work we assessed the presence of two well-known pesticides (DDT and lindane) along with their main metabolite or isomer in tobacco products from 11 countries. In 11 of the 14 samples DDTs were the dominant compounds, with maximum concentrations of ppʹ-DDT in Morocco cigarettes (9 ng g〈sup〉−1〈/sup〉) and of ppʹ-DDE in Italian cigars (13 ng g〈sup〉−1〈/sup〉). Moreover, the α/γ-HCH ratio was mostly lower than 1, indicating the main use of “Lindane” formulation. However, all the detected levels were below the guidance residue values of respective pesticide and metabolite/isomer.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 218〈/p〉 〈p〉Author(s): Ishwar Chandra Yadav, Ningombam Linthoingambi Devi, Vipin Kumar Singh, Jun Li, Gan Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Raising population, deteriorating environmental conditions and limiting natural resources to handle the key environmental health problems have critically affected human health and the environment. Policy makers and planners in Nepal are more concerned today than at any other time in the past about the deterioration of the environmental condition. Therefore, understanding the connection between pollution and human wellbeing is fundamental endeavors to control pollution exposures and secure human wellbeing. This ability is especially critical for countries like Nepal where the issues of environmental pollution have customarily taken a second place to request for economic development. In this study, spatial distribution and sources of 12 heavy metals (HMs) were investigated in surface soils (n = 24) and house dust (n = 24) from four major urban areas of Nepal in order to mark the pollution level. Additionally, a health risk was estimated to establish the link between HMs pollution and human health. Results showed that the median concentration of Ag, Cd, Co, Cr, Cu, Ni, Pb, Sb, Mn and Zn in soil and dust were 2–13 times greater than the background value. The As, Zn, Cu, Cd, and Pb showed a relatively higher spatial variability in soil and dust. Zn was the most abundant metal measured in dust and soil and accounted for 59% and 55% of ∑〈sub〉7〈/sub〉HMs, respectively. The HMs in soil and dust were poorly correlated with total organic carbon (TOC) and black carbon (BC), suggesting little or no influence on HMs contamination. Source analysis study indicated the distribution of Cr, Ni, Sb, Ag, Pb, Cu, and Zn in soil and dust are mainly affected by anthropogenic sources, particularly traffic emissions, industrial source, and domestic households materials, while Co, Fe, As, Mn and Cd were from natural sources. The estimated carcinogenic risk (CR) of HMs in soil and dust exceeded the acceptable level of human exposure, recommending significant CR to the local population.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518323099-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 297〈/p〉 〈p〉Author(s): I. Novak Jovanović, D. Jadreško, A. Miličević, M. Hranjec, N. Perin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The electrochemical behaviour of potential antitumor benzimidazole derivatives (benzo[〈em〉b〈/em〉]thieno[2,3-〈em〉b〈/em〉]pyrido[1,2-〈em〉a〈/em〉]benzimidazoles and benzimidazo[1,2-〈em〉a〈/em〉]quinolines) bearing one or two piperazine substituents was studied at a glassy carbon electrode (GCE) using cyclic and square-wave voltammetry in a wide range of pH values and potential scan rates. The electrochemical oxidation of the studied benzimidazoles proceeded 〈em〉via〈/em〉 one or two electrode reactions assigned to the oxidation of one or two piperazine substituents, respectively. The oxidation of piperazine ring involved the transfer of two electrons and one proton in a pH-dependent, kinetically controlled electrode reaction, followed by a homogenous chemical reaction (EC mechanism). Both the reactants and the products of EC reactions were strongly adsorbed on the GCE surface. The electrochemical reduction occurred in one quasireversible, pH-dependent step, followed by a chemical transformation of the electrochemically formed product. The proposed reduction mechanism was related to the cyano moiety. The assignment of electroactive sites in molecules of interest was confirmed by theoretically calculated, using the PM6 method, differences of Net atomic charges between the cation (or anion) and neutral molecule.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 20 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 297〈/p〉 〈p〉Author(s): T.W. Cain, C.F. Glover, J.R. Scully〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The corrosion behavior of solid solution Mg-xSn (x = 1, 5, 10 wt%) alloys is explored as a function of Sn content in chloride-containing conditions. A suite of 〈em〉in situ〈/em〉 electrochemical techniques and an 〈em〉in situ〈/em〉 scanning vibrating electrode technique (SVET) is utilized to assess free corrosion rates and the extent of cathodic activation. The latest advances in improving the corrosion resistance of Mg alloys have demonstrated that micro-alloying with As or Ge can greatly lower corrosion rates compared to pure Mg and retard cathodic activation to a substantial degree. To broaden the options for suitable non-toxic alloying elements beyond Ge, the current article demonstrates a decreasing corrosion rate by 77%, 85% and 95% for Sn additions of 1%, 5% and 10% (wt%) respectively, when compared to HP Mg freely corroding in 0.6 M aqueous NaCl. A corrosion film formed on Mg-10Sn which displays superior barrier properties. Polarization resistance (R〈sub〉p〈/sub〉) values consistently one order of magnitude greater than that obtained on HP Mg, and the other Mg-Sn alloys, over a 24 h immersion period is demonstrated. Furthermore, the extent of cathodic activation for Mg-10Sn is shown to be reduced by 94% relative to HP Mg. The work presented herein provides advancements in the understanding of corrosion resistant Mg alloys and is pertinent to the potential use of Mg-Sn alloys in transport applications, battery electrode materials and as a candidate sacrificial anode for the cathodic protection of Mg alloy AZ31B-H24. Prospects for protection are discussed.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 20 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 297〈/p〉 〈p〉Author(s): Ting-Feng Yi, Jie Mei, Ying Xie, Shaohua Luo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Spherical flowerlike NiOand NiO@CeO〈sub〉2〈/sub〉(2.5, 5.0 and 7.5 wt%) composites are successfully prepared by a simple hydrothermal method. NiOmaterials show spherical flower morphology with a radius of 4–5 μm, and the CeO〈sub〉2〈/sub〉nano-particles deposit on the surface of NiOpetals (nanosheets), and then form porous NiO@CeO〈sub〉2〈/sub〉flower-like microspheres. NiOpetals are covered with electrochemical active CeO〈sub〉2〈/sub〉nanoparticles, leading to an advantageous synergistic storage effect due to the charge redistribution in the NiO|CeO〈sub〉2〈/sub〉interface, which can decrease the polarization and accelerate the ion diffusion. NiO@CeO〈sub〉2〈/sub〉(5.0 wt%) electrode shows an excellent specific capacitance of 960.4 F g〈sup〉−1〈/sup〉at 20 A g〈sup〉−1〈/sup〉and keeps about 95.84% capacitance retention after 10000 cycles. Whereas the NiO, NiO@CeO〈sub〉2〈/sub〉(2.5 wt%) and NiO@CeO〈sub〉2〈/sub〉(7.5 wt%) electrodes have capacitances of 543.6, 1428 and 1143.6 F g〈sup〉−1〈/sup〉corresponding to capacitance retentions of 74.39%, 62.55% and 58.41% after 10000 cycles, respectively. The first-principles calculation exhibits that a strong chemical bond between O and Ce(Ni) can be formed at the interface, and such a chemical bonding between the two components is very helpful for the stabilization of the composite during repeated cycles, responsible for the good cycling performance of the materials. Therefore, the super capacitance and excellent cycling stability of NiO@CeO〈sub〉2〈/sub〉(5.0 wt%) electrode at high current density can be ascribed to the unique composition design and architectures.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S001346861832735X-fx1.jpg" width="392" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 297〈/p〉 〈p〉Author(s): Jin-xing Kang, Ya-li Feng, Hao-ran Li, Zhu-wei Du, Xiang-yi Deng, Hong-jun Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The reductive dissolution of pyrolusite in simulated 〈em〉Acidithiobacillus ferrooxidans〈/em〉 bio-leaching medium was investigated. This study was performed in three stages. First, the advantageous electrochemical test conditions, parallel to the optimal bio-leaching conditions and adopting the Mn reduction rate, were determined by imitated electrolysis. The facilitation of 〈em〉A. ferrooxidans〈/em〉 on MnO〈sub〉2〈/sub〉 reduction is sensitive to pH and Fe(III) concentration. Second, electrochemical tests revealed that the reductive dissolution of manganese dioxide incorporated two single electron and proton steps-the first exchange of MnO〈sub〉2〈/sub〉 to MnO·OH, and then conversion to Mn(OH)〈sub〉2〈/sub〉 for diffusion. The results of transient and steady electrochemical measurements indicated that the first electron-transfer significantly affects the rate controlling step of Mn-leaching in control(9K) medium, while using 〈em〉A. ferrooxidans〈/em〉 and Fe(III) in the solution tends to enable the leaching rate to be controlled by the latter electron transfer step. Third, the analysis of semiconductor and carrier properties of passive films of pyrolusite formed in the different solutions, illustrated that the reductive dissolution of manganese dioxide tends to depend on the movement of the holes. The first electron preferentially reacts with the shallow energy level of the O-vacancy to form MnO〈sub〉2〈/sub〉〈sup〉·-〈/sup〉, which then absorbs H〈sup〉+〈/sup〉 to become MnO·OH. The second electron participates in the transformation of MnO·OH to (MnOH)(OH) and then to Mn(OH)〈sub〉2〈/sub〉. 〈em〉A. ferrooxidans〈/em〉 increases the carrier densities of the passivating film accelerating electron and proton transfer and Fe(III) primarily influences the shallow donor density of oxygen during the first electron-exchange. Additionally, the synergistic effect of 〈em〉A. ferrooxidans〈/em〉 and Fe(III) on manganese dioxide ore reductive leaching is confirmed.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Lilian Dalago Salgado, Antonio Ernesto Meister Luz Marques, Rafael Duarte Kramer, Fernando Garrido de Oliveira, Sarah Lott Moretto, Barbara Alves de Lima, Maritana Mela Prodocimo, Marta Margarete Cestari, Júlio Cesar Rodrigues de Azevedo, Helena Cristina Silva de Assis〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study combined data of the concentrations of metals, polycyclic aromatic hydrocarbons (PAHs) and pharmaceuticals and personal hygiene products (PPCPs) in the sediments and the biological responses of the 〈em〉Atherinella brasiliensis〈/em〉 fish in two different sites and climate seasons in the Estuarine-Lagoon Complex of Iguape-Cananéia, Southeast Brazil. The presence of metals, PAHs, and PPCPs were observed in the sediments demonstrating the contamination throughout the system with contributions of sewage and residues disposal, oil and combustion of biomass and fossil fuels. Higher contaminations were identified in the point of greater human presence (C - Cananéia City), especially during the cold-dry season. The influence of anthropic activities and variations in the estuarine conditions, such as lower hydrodynamics during the lower rainfall period, were observed. In fish, spatial and seasonal changes in the parameters of oxidative stress and biotransformation, genotoxicity and histopathological alterations followed the same trend, with more pronounced responses in C in the cold-dry season. The biological responses of the fish revealed adverse effects in the local species population and indicated the presence of metals, PAHs and PPCPs as stressors. The multivariate analysis and the integrated biomarker response index (IBR) corroborated with these results, also indicating that site C had the worst environmental quality. The present study provides new information about the contamination of the sediments of Estuarine-Lagoon Complex of Iguape-Cananéia and the chronic exposure to contaminants in 〈em〉A. brasiliensis〈/em〉. Therefore, contributing to a better understanding of the local environmental quality with data that can support protective management of the area.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 218〈/p〉 〈p〉Author(s): Ronan Guillossou, Julien Le Roux, Romain Mailler, Emmanuelle Vulliet, Catherine Morlay, Fabrice Nauleau, Johnny Gasperi, Vincent Rocher〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Several advanced treatments, such as ozonation or activated carbon adsorption, are currently considered for the removal of organic micropollutants (OMPs) in wastewater treatment plants (WWTP). However, little is known on the overall performances of a WWTP upgraded with those processes and the benefits provided regarding the elimination of multiple families of OMPs. In this study, 5 sampling campaigns were performed to determine the removal of 48 OMPs in a WWTP followed by an activated carbon pilot. The primary treatment had no effect on OMPs (removals 〈 20%), whereas the biological treatment removed OMPs that can be easily sorbed onto sludges or biodegraded (〉60%). The additional elimination provided by the advanced treatment was not significant (〈10%) for OMPs already well removed in the WWTP) but was substantial (〉30%) for recalcitrant OMPs. Removals higher than 60% were obtained for all OMPs (except azithromycin and sulfamethoxazole) over the WWTP and the activated carbon pilot. The adsorption conditions (10 g/m〈sup〉3〈/sup〉 fresh activated carbon addition) were not sufficient to achieve the 80% removal targeted in Switzerland for compounds suggested as indicator substances for wastewater treatment. A higher dose of activated carbon or the combination with another advanced treatment should be used to achieve a satisfactory removal of those compounds.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518322896-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 218〈/p〉 〈p〉Author(s): Moonis Ali Khan, Ayoub Abdullah Alqadami, Marta Otero, Masoom Raza Siddiqui, Zeid Abdullah Alothman, Ibrahim Alsohaimi, M. Rafatullah, Abdelrazig Elfaki Hamedelniel〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Efforts to improve water quality have led to the development of green and sustainable water treatment approaches. Herein, nitrogen-doped magnetized hydrochar (mSBHC-N) was synthesized, characterized, and used for the removal of post-transition and transition heavy metals, viz. Pb〈sup〉2+〈/sup〉 and Cd〈sup〉2+〈/sup〉 from aqueous environment. mSBHC-N was found to be mesoporous (BET surface area – 62.5 m〈sup〉2〈/sup〉/g) and paramagnetic (saturation magnetization – 44 emu/g). Both, FT-IR (with peaks at 577, 1065, 1609 and 3440 cm〈sup〉−1〈/sup〉 corresponding to Fe – O stretching vibrations, C – N stretching, N – H in-plane deformation and stretching) and XPS analyses (with peaks at 284.4, 400, 530, 710 eV due to C 1s, N 1s, O 1s, and Fe 2p) confirmed the presence of oxygen and nitrogen containing functional groups on mSBHC-N. The adsorption of Pb〈sup〉2+〈/sup〉 and Cd〈sup〉2+〈/sup〉 was governed by oxygen and nitrogen functionalities through electrostatic and co-ordination forces. 75–80% of Pb〈sup〉2+〈/sup〉 and Cd〈sup〉2+〈/sup〉 adsorption at 〈em〉C〈/em〉〈sub〉〈em〉o〈/em〉〈/sub〉: 25 mg/L, either from deionized water or humic acid solution was accomplished within 15 min. The data was fitted to pseudo-second-order kinetic and Langmuir isotherm models, with maximum monolayer adsorption capacities being 323 and 357 mg/g for Cd〈sup〉2+〈/sup〉and Pb〈sup〉2+〈/sup〉 at 318 K, respectively. Maximum Cd〈sup〉2+〈/sup〉 (82.6%) and Pb〈sup〉2+〈/sup〉 (78.7%) were eluted with 0.01 M HCl, simultaneously allowing minimum iron leaching (2.73%) from mSBHC-N. In conclusion, the study may provide a novel, economical, and clean route to utilize agro-waste, such as sugarcane bagasse (SB), for aquatic environment remediation.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518323178-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 218〈/p〉 〈p〉Author(s): Meng-Ru Jia, Ni Tang, Yue Cao, Yanshan Chen, Yong-He Han, Lena Q. Ma〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Arsenate (AsV) reduction in bacteria is essential to alleviate their arsenic (As) toxicity. We isolated a 〈em〉Bacillus〈/em〉 strain PVR-YHB1-1 from the roots of As-hyperaccumulator 〈em〉Pteris vittata〈/em〉. The strain was efficient in reducing AsV to arsenite (AsIII), but the associated mechanisms were unclear. Here, we investigated its As resistance and reduction behaviors and associated genes at genome level. Results showed that the strain tolerated up to 20 mM AsV. When grown in 1 mM AsV, 96% AsV was reduced to AsIII in 48 h, with its AsV reduction ability being positively correlated to bacterial biomass. Two 〈em〉ars〈/em〉 operons 〈em〉arsRacr3arsCDA〈/em〉 and 〈em〉arsRKacr3arsC〈/em〉 for As metabolisms were identified based on draft genome sequencing and gene annotations. Our data suggested that both operons might have attributed to efficient As resistance and AsV reduction in PVR-YHB1-1, providing clues to better understand As transformation in bacteria and their roles in As transformation in the environment〈em〉.〈/em〉〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518322525-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 218〈/p〉 〈p〉Author(s): Yang Wang, Baoyu Gao, Shuya Li, Bo Jin, Qinyan Yue, Zhining Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Cerium oxide (CeO〈sub〉2〈/sub〉) nanoparticles (NPs) have indicated great potentials as nanofiller owing to its high surface area, antioxidant properties and low cost. In this paper, thin film nanocomposite (TFN) RO membranes were proposed to be prepared through incorporation of hydrophilic CeO〈sub〉2〈/sub〉 NPs in polyamide (PA) selective layers via interfacial polymerization (IP). EDX, XPS, SEM, AFM, contact angle and zeta potential were used to examine the property and morphology of the prepared membranes. CeO〈sub〉2〈/sub〉 NPs were successfully embedded in the PA network, which endowed the TFN membranes with rougher surfaces and thinner PA layers. The TFN membranes were fabricated with different CeO〈sub〉2〈/sub〉 NPs contents (0, 50, 100, 150, 200, 400 mg/L). With increasing CeO〈sub〉2〈/sub〉 NPs loading amount, the hydrophilicity improved from 85.4° to 65.7° and the surface charge declined from −19.4 to −34.2 mV. These characteristics contributed to a 50% enhancement in water flux of TFN-CeO〈sub〉2〈/sub〉100 membrane (containing 100 mg/L of CeO〈sub〉2〈/sub〉 NPs) without compromise the NaCl rejection (98%). Moreover, CeO〈sub〉2〈/sub〉 embedded membrane exhibited an enhanced fouling resistance property through preventing the adhesion of hydrophobic foultants. This study demonstrated the desirable applicability of CeO〈sub〉2〈/sub〉 NPs in synthesizing novel TFN membranes for desalination application.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518323142-egi1097WLGG903.jpg" width="330" alt="Image 1097903" title="Image 1097903"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 218〈/p〉 〈p〉Author(s): Jiexin Li, Chunhong Shi, Huifeng Zhang, Xinfei Zhang, Yangyang Wei, Kai Jiang, Baogang Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Silicalite-1 (S-1) zeolite membrane synthesized by seed method with superior features attracts intensive attentions, while the influences of key parameters during synthesis process and its applications for organics removal require further investigation. This study revealed the morphology and the structure of the prepared membranes under different crystallization temperatures and seed concentrations by using a suite of characterization methods. The as-prepared membrane under optimal condition (crystallization temperature of 175 °C and seed concentration of 1.0 wt. %) possessed high membrane integrity, with ideal separation factor of 4.0. It also exhibited outstanding performance for organics removal, with dyes retention of 99.9% and 99.2% for 500 mg L〈sup〉−1〈/sup〉 neutral red and 500 mg L〈sup〉−1〈/sup〉 methyl blue, respectively. Excellent antifouling property of the synthesized membrane was also proved. Results of this work can guide the characteristic improvement of the S-1 zeolite membrane by adjusting key parameters and broaden its applications in dye wastewater treatment.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 218〈/p〉 〈p〉Author(s): Zhipan Wen, Yalei Zhang, Gang Cheng, Yingru Wang, Rong Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, nanosized ordered magnetic mesoporous Fe-Ce bimetal oxides (Nanosized-MMIC) with highly well-ordered inner-connected mesostructure were successfully synthesized through the KIT-6 template method. This Nanosized-MMIC displayed excellent adsorption capacities for As(V), Cr(VI) and AO7, and the corresponding calculated maximum adsorption capacities of material were 111.17, 125.28 and 156.52 mg/g, respectively. As(V) and Cr(VI) removal by Nanosized-MMIC were slightly dependent on the ionic strength but highly solution pH-dependent, the coexistent silicate and phosphate ions competed remarkably with both As(V) and Cr(VI) for the adsorption active site. Mechanisms indicated As(V) and Cr(VI) formed inner-sphere complexes on Nanosized-MMIC interface via the electrostatic interaction and surface complexation, while the total organic carbon (TOC) change demonstrated that AO7 could be removed completely and no organic intermediates formed through the adsorption process. In addition, Nanosized-MMIC also possessed superior adsorption performance in As(V)/Cr(VI)-AO7 binary systems, and the reusable and regeneration properties indicated that the obtained nanomaterials could maintain at a comparatively high level after several recycling. Finally, fixed-bed experiments suggested the Nanosized-MMIC was expected to have a promising excellent nano-adsorbent with high application potential for co-existed toxic heavy metals and organic dyes removal in practical wastewater treatment.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518323154-fx1.jpg" width="288" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 218〈/p〉 〈p〉Author(s): Tian Li, Yao Wang, Jian Hou, Dan Zheng, Guiyang Wang, Chen Hu, Tian Xu, Juan Cheng, Wenjun Yin, Xiang Mao, Lin Wang, Zhenyu He, Jing Yuan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Exposure to fine particulate matter (PM〈sub〉2.5〈/sub〉) is linked to various respiratory outcomes. However, the associations of concentrations of PM〈sub〉2.5〈/sub〉-bound polycyclic aromatic hydrocarbons (PM〈sub〉2.5〈/sub〉-bound PAHs) with airway inflammatory indices remains unclear. To assess effects of short-term exposure to PM〈sub〉2.5〈/sub〉-bound PAHs on fractional exhaled nitric oxide (FeNO), we conducted a pilot study with repeated measures. We recruited 20 postgraduate students in Wuhan city, China, and repeatedly measured outdoor and indoor (including dormitories, offices and laboratories) PM〈sub〉2.5〈/sub〉-bound PAHs concentrations, urinary monohydroxy polycyclic aromatic hydrocarbons (OH-PAHs) and FeNO levels in the four seasons. Subsequently, we estimated inhaled doses of PM〈sub〉2.5〈/sub〉-bound PAHs based on the micro-environmental PM〈sub〉2.5〈/sub〉-bound PAHs concentrations, time-activity patterns and referred inhalation rates. We assessed the association of inhaled doses of PM〈sub〉2.5〈/sub〉-bound PAHs with FeNO using linear mixed-effects regression models. We found the positive associations of urinary ∑OH-PAHs levels with inhaled doses of indoor PM〈sub〉2.5〈/sub〉-bound PAHs (including dormitories and offices) (all p 〈 0.05). A one-unit increase in inhaled doses of PM〈sub〉2.5〈/sub〉-bound PAHs or in urinary concentrations of ∑OH-PAHs was corresponded to a maximum FeNO increase of 13.5% (95% CI: 5.4, 22.2) at lag2 day or of 6.8% (95% CI: 3.4, 10.2) at lag1 day. Inhaled doses of PM〈sub〉2.5〈/sub〉-bound PAHs or urinary OH-PAHs was positively related to increased FeNO, they may be accepted as a short-term biomarker of exposure to PAHs in air. Exposure to PM〈sub〉2.5〈/sub〉-bound PAHs in indoor air may contribute more to the body burden of PAHs than outdoor air, and exhibited stronger effect on increased FeNO rather than urinary OH-PAHs.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518323038-fx1.jpg" width="466" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Yang Wan, Xin Huang, Baoyou Shi, Jian Shi, Haotian Hao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Typical Chinese source water has high content of low molecular weight and aromatic protein-like organic matter which is difficult to remove and poses a great challenge to conventional coagulation/flocculation. To investigate coagulation performance of this typical water, this research focused on organic matter removal characteristics and the associated disinfection byproducts formation potentials (DBPFPs) during the coagulation process by titanium salts compared with traditional aluminum and ferric salts. Results showed that based on the dissolved organic matter (DOM) removal, the optimal coagulant dosages of AlCl〈sub〉3〈/sub〉, FeCl〈sub〉3〈/sub〉 and TiCl〈sub〉4〈/sub〉 were 0.5 mM and the optimal initial pH values were 8, indicating that the DOM in the typical Chinese water could be effectively removed through sweeping and adsorption by metal hydroxides rather than the complexation and charge neutralization effect under acidic conditions. Compared these three coagulants, the highest ultra violet absorbance at 254 nm removal rate of 72.9% was achieved by TiCl〈sub〉4〈/sub〉. The three-dimensional excitation emission matrix results showed that the removal ability of humic acids by AlCl〈sub〉3〈/sub〉 was poorer than FeCl〈sub〉3〈/sub〉 and TiCl〈sub〉4〈/sub〉. The removal rate of low molecular weight components (1600 Da) by TiCl〈sub〉4〈/sub〉 was 20% higher than using AlCl〈sub〉3〈/sub〉 and 14% higher than FeCl〈sub〉3〈/sub〉. Comparing with AlCl〈sub〉3〈/sub〉 and FeCl〈sub〉3〈/sub〉, TiCl〈sub〉4〈/sub〉 had a better performance on the control of DBPFPs, especially for chloroform and dichloroacetic acid, due to its higher removal ability of aromatic organics. The trihalomethane formation potentials removal rate by TiCl〈sub〉4〈/sub〉 was three times higher than that by AlCl〈sub〉3〈/sub〉 and twice by FeCl〈sub〉3〈/sub〉, by which could be inferred that titanium salts achieved better removal of low molecular weight organic matter than aluminum and ferric salts.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518322240-fx1.jpg" width="341" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 218〈/p〉 〈p〉Author(s): Jia Wang, Xiao-Wen Zeng, Michael S. Bloom, Zhengmin Qian, Leslie J. Hinyard, Rhonda Belue, Shao Lin, Si-Quan Wang, Yan-Peng Tian, Mo Yang, Chu Chu, Namratha Gurram, Li-Wen Hu, Kang-Kang Liu, Bo-Yi Yang, Dan Feng, Ru-Qing Liu, Guang-Hui Dong〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Perfluoroalkyl substances (PFASs) are widely-utilized synthetic chemicals commonly found in industrial and consumer products. Previous studies have examined associations between PFASs and renal function, yet the results are mixed. Moreover, evidence on the associations of isomers of PFASs with renal function in population from high polluted areas is scant. To help to address this data gap, we used high performance liquid chromatography-mass spectrometry to measure serum isomers of perfluorooctanoate (PFOA), perfluorooctanesulfonate (PFOS), and other PFASs from 1612 adults residing in Shenyang, China, and characterized their associations with estimated glomerular filtration rate (eGFR) and chronic kidney disease (CKD). Results showed that after adjusted for multiple confounding factors, most of the higher fluorinated PFASs, except for PFOA and PFDA, were negatively associated with eGFR and positively associated with CKD. Compared with linear PFOS (n-PFOS), branched PFOS isomers (Br-PFOS) were more strongly associated with eGFR (Br-PFOS; β = −1.22, 95%CI: 2.02, −0.42; 〈em〉p〈/em〉 = 0.003 vs. n-PFOS; β = −0.16, 95%CI: 0.98, 0.65; 〈em〉p〈/em〉 = 0.691) and CKD (Br-PFOS; OR = 1.27; 95% CI: 1.02, 1.58; 〈em〉p〈/em〉 = 0.037 vs. n-PFOS; OR = 0.98; 95% CI: 0.80, 1.20; 〈em〉p〈/em〉 = 0.834). In conclusion, branched PFOS isomers were negatively associated with renal function whereas their linear counterparts were not. Given widespread exposure to PFASs, potential nephrotoxic effects are of great public health concern, Furthermore, longitudinal research on the potential nephrotoxic effects of PFASs isomers will be necessary to more definitively assess the risk.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 20 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 297〈/p〉 〈p〉Author(s): Nilanjan Chakrabarty, Amit K. Chakraborty〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Controlling the electrochemical performance of electrodes for application in supercapacitor has received large research interest in the recent years. Here we report the facile synthesis of a Ni(OH)〈sub〉2〈/sub〉 and carbon nanotubes based nanohybrid electrode and control its electrochemical performance for application in supercapacitor by La doping. A systematic investigation of the influence of a number of electrochemical parameters of measurement on the electrode properties is also presented. Structural and morphological analyses show formation of hexagonal nanoparticles (∼35 nm) well attached on the walls of carbon nanotubes (CNT) while elemental analysis confirms the success of La doping. The nanohybrid sample doped with 1 mol% La (with respect to Ni) appears to be the best performing electrode exhibiting specific capacitance of 2731 F/g at 1 A/g, energy density of 25 Wh/kg at power density of ∼1 kW/kg and capacity retention of 84% even after 5000 cycles which are higher than previously reported values for Ni(OH)〈sub〉2〈/sub〉 based electrodes and also the first of its kind in which β-Ni(OH)〈sub〉2〈/sub〉 has been combined with CNT and doped with La. Increase in the specific surface area as well as electrical conductivity of Ni(OH)〈sub〉2〈/sub〉 by incorporation of CNT and La dopants are the main reasons for the improved performance of the 1 mol% La doped composite whereas formation of insulating La(OH)〈sub〉3〈/sub〉 is responsible for the inferior performance of electrodes containing more than 1 mol% La. The charge storage mechanism has been found to be governed by both capacitive and diffusion processes at high scan rates but dominated by only diffusion process at low scan rates.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 218〈/p〉 〈p〉Author(s): Wenfang Li, Rui Yu, Ming Li, Na Guo, Hongwen Yu, Yong Yu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel ternary nanocomposite photocatalyst, Ag-BiOI- reduced graphene oxide (rGO), driven by visible light was successfully synthesized with hydrothermal strategy. XRD, SEM, TEM, HRTEM, EDS, raman spectroscopy, XPS, DRS, photocurrent and EIS analysis were employed to characterize all synthesized compounds. Compared to pure BiOI, Ag-BiOI and BiOI-rGO, the 5 mol% Ag-BiOI-rGO 5 wt% displayed superior photocatalytic capability with complete removal of diclofenac (10.0 μg mL〈sup〉−1〈/sup〉) in 80 min under visible light. The characterization results indicated that the addition of Ag and rGO enhanced the charge separation and suppressed the recombination of photogenerated electrons and holes, which upgraded the ability of Ag-BiOI-rGO to degrade diclofenac compared with BiOI. Six reaction intermediates of diclofenac were detected by LC-MS/MS, subsequently, two degradation routes were proposed. This work provides a promising strategy to fabricate more effective photocatalysts to deal with organic pollutants in wastewater.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518322926-fx1.jpg" width="281" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 218〈/p〉 〈p〉Author(s): Olugbenga J. Owojori, Oluwadamilare T. Ademosu, Olukayode O. Jegede, Hamzat O. Fajana, Temitope O. Kehinde, Mosadoluwa A. Badejo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The oribatid mite, 〈em〉Oppia nitens,〈/em〉 has gained recognition in recent laboratory ecotoxicological tests, however, the species global distribution is limited to temperate regions and not ecologically relevant for tropical soils. The present study reports the first laboratory study aimed at assessing the ecotoxicity of contaminants with the tropical oribatid mite, 〈em〉Muliercula inexpectata〈/em〉. To develop the protocols, synchronized adult specimens of 〈em〉M. inexpectata〈/em〉 were tested in a natural soil collected at the Teaching and Research Farm of the Obafemi Awolowo University, Ile-Ife, Nigeria. An optimization test was done using different soil quantities (5, 20, 40 g), durations (14, 21, 28 d) and temperature regimes (20, 22, 24, 26, and 28 °C). The results show 〈em〉M〈/em〉. 〈em〉inexpectata〈/em〉 peak juvenile production at 28 d and temperatures of 24–26 °C in 20 g of soil. Test conditions were further optimized to assess the effects of cadmium and dimethoate on adult lethality and reproduction of 〈em〉M. inexpectata〈/em〉 using 20 g of soil, with an exposure temperature of 26 °C for a duration of 28 d. The LC50 (survival) and EC50 (reproduction) values of cadmium for 〈em〉M. inexpectata〈/em〉 were 46.55 (26.26–82.52) mg/kg and 15.61 (13.65–20.63) mg/kg, respectively. The LC50 and EC50 values of dimethoate for 〈em〉M. inexpectata〈/em〉 were 7.57 (5.40–10.60) and 4.42 (0–7.16) mg/kg, respectively. Compared to other mite species, they are either more or less sensitive depending on the chemicals considered. The results of the present study demonstrate that 〈em〉M. inexpectata〈/em〉 is a promising candidate for routine and ecologically-relevant ecotoxicological assessments in tropical regions.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 20 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 297〈/p〉 〈p〉Author(s): Kyeongmin Oh, Milad Moazzam, Geonhui Gwak, Hyunchul Ju〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Water crossover through the membrane of a vanadium redox flow battery system is not desirable because it floods one half-cell, diluting the vanadium solution on one side and consequently increasing the concentration of vanadium in the other half-cell. To analyze the effect of water crossover and the resultant electrolyte imbalance issue in the vanadium redox flow battery, herein we newly develop a water transport model and incorporate it into our previously developed 3D vanadium redox flow battery model. The model rigorously accounts for water production/consumption by the redox reaction of VO〈sup〉2+〈/sup〉/VO〈sub〉2〈/sub〉 and side reactions as well as various mechanisms of water crossover through the membrane arising from diffusion, electro-osmotic drag (EOD), and vanadium crossover. The numerical model is successfully validated against in situ data collected during experiments in which the electrolyte volumes and cell voltages are measured during charge–discharge cycles carried out under various current densities. The detailed simulation results clearly elucidate water crossover behaviors at different stages of charging and discharging, and further reveal the individual contributions of water crossover mechanisms to the overall electrolyte imbalance between the negative and positive sides of the VRFB system.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 20 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 297〈/p〉 〈p〉Author(s): Jui-Hong Weng, Chih-Yu Lai, Lin-Chi Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper studies the electrochemical measurements of ferricyanide redox reaction with two symmetric Au microelectrodes in microfluidics under one-way and shuttle flow conditions. An equal-molar Fe(CN)〈sub〉6〈/sub〉〈sup〉3−〈/sup〉/Fe(CN)〈sub〉6〈/sub〉〈sup〉4−〈/sup〉 mixture was assayed with micro-fabricated Au electrodes placed inside a PDMS microfluidic channel by cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) under a static or flow condition, respectively. It was found that the alignment and dimensions of microelectrodes played a crucial role in determining the electrochemical characteristics. Moreover, the redox characteristics were observed to be “tuneable” through microfluidic operations. Under the one-way flow mode, the CV response underwent a flow polarization effect that enhanced the downstream electrode reaction. Also, CV pattern transition from a typical wave shape to a sigmoidal curve was observed while increasing the flow rate for a microfluidic channel with a height ≤100 μm. In addition, steady-state CA responses instead of Cottrell-type currents were obtained owing to the convection-assisted mass transfer of ferricyanide. Under the shuttle flow mode, a liquid periodic motion effect was imposed on the CV measurement that resulted in oscillatory signals. By contrast, peak currents were produced in pairs periodically in the shuttle-mode CA, which were well-suited for redox quantitation and assessing the micro-mixing effect. Finally, both flow modes were proven effective to improve the detection sensitivity of microfluidic amperometry.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Two-electrode cyclic voltammetry and amperometry on a chip tuned with one-way and shuttle microfluidics.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0013468618326112-fx1.jpg" width="347" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 218〈/p〉 〈p〉Author(s): Heyun Fu, Kun Liu, Pedro J.J. Alvarez, Daqiang Yin, Xiaolei Qu, Dongqiang Zhu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The hydrophobicity of natural organic matter (NOM) is of great significance for its interfacial processes in natural and engineered systems. However, there is no well-accepted method for the routine determination of NOM hydrophobicity. In this study, the hydrophobicity of NOM spanning a wide range of origins and properties was quantified based on their partition coefficients (〈em〉K〈/em〉〈sub〉ATPS〈/sub〉) in poly (ethylene glycol)/potassium citrate aqueous two-phase systems (ATPS). The Ln〈em〉K〈/em〉〈sub〉ATPS〈/sub〉 of NOM correlated well with the elemental, structural, and thermodynamic indices commonly used to characterize NOM hydrophobicity, including (O + N)/C, O/C, aromatic and aliphatic carbon, and the free energy of interactions between molecules (Δ〈em〉G〈/em〉〈sub〉iwi〈/sub〉). A simple linear model was developed to predict NOM hydrophobicity using 〈em〉K〈/em〉〈sub〉ATPS〈/sub〉. The model was validated using 20 natural water samples collected from rivers and lakes, which suggested good prediction power. ATPS scale system is simple, fast, low-cost, environmentally friendly, and requires little pretreatment and small sample volume. Overall, 〈em〉K〈/em〉〈sub〉ATPS〈/sub〉 can be used as quantitative measure of NOM hydrophobicity that facilitates routinely characterizing the interfacial properties of NOM.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518322902-fx1.jpg" width="308" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 218〈/p〉 〈p〉Author(s): Soraya Paz, Carmen Rubio, Inmaculada Frías, Ángel J. Gutiérrez, Dailos González-Weller, Verónica Martín, Consuelo Revert, Arturo Hardisson〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Algae are becoming increasingly common because of their importance in vegan and vegetarian diets. Although they are a source of essential minerals, vitamins and antioxidants, these marine organisms have a high absorption capacity that can lead to the accumulation of toxic metals which are dangerous in humans. The objective of this study is to determine the content of toxic metals (Al, Cd, Pb and Hg) in edible seaweed samples marketed in Spain (Europe) to assess the toxicological risk from the intake of these metals. A total of 73 European and Asian algae samples marketed in Tenerife (Canary Islands, Spain) were analyzed by ICP - OES (Inductively Coupled Plasma – Optical Emission Spectrometry) and by CV-AAS (Cold Vapor – Atomic Absorption Spectrophotometry). The major toxic metal was Al, whose highest level was recorded in seaweed salad (57.5 mg Al/kg dry weight). Regarding the origin, the highest concentrations of Al (38.9 mg/kg dw), Cd (0.59 mg/kg dw) and Pb (0.40 mg/kg dw) were found in Asian algae, which may be due to the high levels of industry in the Asian countries. However, the highest concentration of Hg (0.017 mg/kg dw) was found in European algae. The consumption of 5 g of dehydrated seaweed per day represents a percentage of contribution to the tolerable weekly intake of Cd of 22.7%, this percentage may entail a risk when considering total Cd intake. However, the consumption of 5 g a day of dehydrated seaweed would not, pose a risk to the health of adults.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 218〈/p〉 〈p〉Author(s): Xiaosan Luo, Zhen Zhao, Jiawen Xie, Jun Luo, Yan Chen, Hongbo Li, Ling Jin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Atmospheric fine particulate matters (PM〈sub〉2.5〈/sub〉) pose significant risks to human health through inhalation, especially in the rapidly developing China due to air pollution. The harmful effects of PM〈sub〉2.5〈/sub〉 are determined not only by its concentrations and hazardous components from diverse sources, but more by their bioavailable fractions actually absorbed by human body. To accurately estimate the inhalation risks of airborne metals, a physiologically based bioaccessibility method combining Simulated Lung Fluid (SLF) extraction and Diffusive Gradients in Thin-films (DGT) approaches was developed, representing the dissolution of particulate metals into lung fluid and the subsequent lung absorption of free metal cations in solution, respectively. The new method was used to compare the lung bioaccessibility of typical trace metals in PM〈sub〉2.5〈/sub〉 from three China megacities (Shanghai and Nanjing in the east, Guangzhou in south) during heavy pollution seasons. Generally, the SLF bioaccessibility (%) simulating the solubility of particulate metals in alveolar lung fluid was in order of Ni 〉 Cd 〉 Mn » Pb, while the succeeding DGT bioaccessibility representing labile metal fractions in solution phase absorbed directly by lung was lower and ranked as Ni ∼ Mn 〉 Cd » Pb, thus Ni and Cd posed relatively higher potential risks owing to their high air pollution level and higher pulmonary bioaccessibility. Due to varied particle sources such as coal combustion and traffic emissions, some airborne metal concentrations (Pb, Ni) showed inconsistent spatial patterns with bulk PM〈sub〉2.5〈/sub〉 concentrations, and also varied bioaccessibility in different regions. The framework for PM〈sub〉2.5〈/sub〉 pollution risk assessments should be refined by considering both aerosol components and associated pollutants' bioaccessibility.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518321866-fx1.jpg" width="482" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 218〈/p〉 〈p〉Author(s): Ying Dong, Hui Wang, E Chang, Zhenjie Zhao, Ruhai Wang, Renkou Xu, Jun Jiang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The types and amounts of cations and their uptake by plants vary with cultivating soils, which correlates with the carbonates and subsequent alkalis contents in the derived biochars. However, regional differences in the alkaline properties of crop straw biochars are unclear. In the present study, biochars pyrolyzed from canola straws collected from four different regions were used to assess the differences in the alkaline properties among them. The biochars were referred to as YTBC, XCBC, NJBC, and HYBC, respectively, and their feedstocks were collected from four different regions from south to north of China. The NH〈sub〉4〈/sub〉OAC exchangeable base cations (K〈sup〉+〈/sup〉, Na〈sup〉+〈/sup〉, Ca〈sup〉2+〈/sup〉, Mg〈sup〉2+〈/sup〉) in the biochars were 270.74, 1427.05, 2089.23, and 1516.48 mmol kg〈sup〉−1〈/sup〉 for YTBC, XCBC, NJBC, and HYBC, respectively, which were roughly consistent with the exchangeable base cations in the corresponding planting soils (17.57, 28.20, 151.26 and 444.65 mmol kg〈sup〉−1〈/sup〉, respectively). The pH, carbonates content, and alkalinity of biochars considerably increased as follows: YTBC 〈 XCBC 〈 NJBC 〈 HYBC. Wheat seedling root elongation experiment indicated that the Al(III) phytotoxicity alleviation effect of the biochars was as follows: HYBC 〉 NJBC 〉 XCBC 〉 YTBC, which was corroborated by the subsequent findings of Evans blue staining, the remnant aluminum (Al(III)) in the reaction solution and Al(III) distribution in the wheat seedling roots. Thus, planting soil had a dominant influence in alleviating Al(III) phytotoxicity, and studies on crop straw biochar properties concerning alkalinities or liming potentials should not only consider crop genera and pyrolysis conditions, but also cultivating conditions.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518322835-fx1.jpg" width="299" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 218〈/p〉 〈p〉Author(s): Qian Zhao, Qingling Liu, Chunfeng Song, Na Ji, Degang Ma, Xuebin Lu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The MnO〈sub〉x〈/sub〉 was immobilized on the CoAl mixed oxides (CoAlO) derived from hydrotalcites with various anions (CO〈sub〉3〈/sub〉〈sup〉2−〈/sup〉, Cl〈sup〉−〈/sup〉, NO〈sub〉3〈/sub〉〈sup〉−〈/sup〉 and SO〈sub〉4〈/sub〉〈sup〉2−〈/sup〉) using the hydration and impregnation methods. The CoAlO oxides modified by KMnO〈sub〉4〈/sub〉 were calcined in air at 300 °C to obtain stable oxides, which could be used as catalysts for VOCs (acetone and ethyl acetate) oxidation. CoAlO with CO〈sub〉3〈/sub〉〈sup〉2−〈/sup〉 and 30 h of hydration time (CoAlO-C-Mn-30) exhibited a promising catalytic activity (T〈sub〉90〈/sub〉 = 173 °C for acetone oxidation; T〈sub〉90〈/sub〉 = 175 °C for ethyl acetate), highly superior to CoAlO without KMnO〈sub〉4〈/sub〉 modification. The improvement in acetone and ethyl acetate catalytic oxidation was ascribed to the Co〈sup〉3+〈/sup〉 and surface adsorbed oxygen species. The increase of Co〈sup〉3+〈/sup〉 in the CoAlO-C-Mn-30 oxide thanked to the self-decomposition of KMnO〈sub〉4〈/sub〉 and reducibility of Co〈sup〉2+〈/sup〉 in the CoAlO oxide during the hydration process. This was also confirmed by XRD and XPS characterization, which showed that Mn cations were enriched on the catalyst surface in the valences of +3 and +4. The catalytic activity of the catalyst remained unchanged in four cycles in the presence of 5.5 vol.% water vapor, which indicated a great potential for industrial application.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉In this work, the MnO〈sub〉x〈/sub〉 was immobilized on the CoAl mixed oxides (CoAlO) derived from hydrotalcites and enriched on the CoAlO surface in the valences of +3 and + 4. This rendered more surface Co〈sup〉3+〈/sup〉 on the catalyst. The presence of Co〈sup〉3+〈/sup〉 improved the low temperature reducibility and surface oxygen species, which are the main contributors for acetone and ethyl acetate oxidation.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518322380-fx1.jpg" width="355" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 10 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 296〈/p〉 〈p〉Author(s): Tankiso Lawrence Ngake, Johannes Hermanus Potgieter, Jeanet Conradie〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The synthesis, identification and electrochemical properties are reported here, for a series of five novel and seven known amino substituted β-amino α,β-unsaturated ketones (bidentate N,O-ligands) of the type CH〈sub〉3〈/sub〉COCHC(NHR)CH〈sub〉3〈/sub〉, where R = H, Ph, CH〈sub〉2〈/sub〉Ph, CH(CH〈sub〉3〈/sub〉)〈sub〉2〈/sub〉, 〈em〉p〈/em〉-CF〈sub〉3〈/sub〉-Ph or 〈em〉p〈/em〉-〈sup〉〈em〉t〈/em〉〈/sup〉Bu-Ph (〈strong〉Series 1〈/strong〉), as well as type PhCOCHC(NHR)CH〈sub〉3〈/sub〉, where R = H, Ph, 〈em〉p〈/em〉-NO〈sub〉2〈/sub〉-Ph, 3,5-di-Cl-Ph, 2-CF〈sub〉3〈/sub〉-4-Cl-Ph, and also PhCOCHC(NHPh)CF〈sub〉3〈/sub〉 (〈strong〉Series 2〈/strong〉). The cyclic voltammograms measured in CH〈sub〉3〈/sub〉CN, generally exhibit both a chemically and electrochemically irreversible reduction peak between −1.2 V and −3.1 V 〈em〉vs〈/em〉 FcH/FcH〈sup〉+〈/sup〉, producing an unstable radical anion, for most of these 1,3-amino ketones. Only ligands PhCOCHC(NHPh)CH〈sub〉3〈/sub〉, PhCOCHC(NHPh)CF〈sub〉3〈/sub〉 and PhCOCHC(NH(〈em〉p〈/em〉-NO〈sub〉2〈/sub〉-Ph))CH〈sub〉3〈/sub〉, showed reversible electrochemical behaviour, at higher scan rates. Density functional theory (DFT) calculations proved the unpaired spin density in the radical anion to be distributed over the 〈em〉pseudo〈/em〉-aromatic O〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉N backbone of the 1,3-amino ketones, extending further over the phenyl rings of the phenyl-containing ligands. Various DFT calculated energies, such as the energy of the lowest unoccupied molecular orbital (the orbital into which the electron is added upon reduction), as well as the DFT calculated gas phase adiabatic electron affinities, relate linearly to the experimentally measured reduction potential. These obtained linear relationships confirmed that good communication via conjugation exists, between the R substituent on the amino group and the rest of the 1,3-amino ketone.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉The electrochemically irreversible reduction potential of a series of twelve amino-substituted β-amino α,β-unsaturated ketones, relates linearly to various computational chemistry calculated energies, thereby describing the electron withdrawing ability of each of the twelve amino substituents.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0013468618326276-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 297〈/p〉 〈p〉Author(s): Libing Yao, Meng Nie, Chongyang Zhu, Ran Cai, Weiwei Xia, Litao Sun, Feng Xu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Developing an electrode material with improved ionic transport dynamics in a battery has been the focus of research. Here, we report a facile one-step hydrothermal synthesis method to prepare anode material of ultra-small SnS nanocrystals (NCs) anchored on N-doped graphene nanosheets (SnS/N-G), which is expected to significantly the dynamics of lithium transport, enabling an exceptional capacity of 1120.3 mAh g〈sup〉−1〈/sup〉 at 0.1 A g〈sup〉−1〈/sup〉 after 130 cycles and superior rate capabilities of 446.3 and 340.7 mAh g〈sup〉−1〈/sup〉 at 2 and 3 A g〈sup〉−1〈/sup〉, respectively. Furthermore, the lithiation/delithiation behaviors of SnS/N-G anode were observed in real time using 〈em〉in situ〈/em〉 transmission electron microscopy to reveal the corresponding kinetics. By tracking the full lithiation procedure, 〈em〉in situ〈/em〉 electron diffraction and high-resolution TEM imaging found that the original SnS phase was firstly transformed to Sn phase by conversion reaction and then to Li〈sub〉22〈/sub〉Sn〈sub〉5〈/sub〉 phase by alloying reaction. Notably, a stable and reversible phase transformation was established between Li〈sub〉22〈/sub〉Sn〈sub〉5〈/sub〉 and Sn phases during subsequent charge-discharge cycles. In the meantime, the volume expansion-induced pulverization of SnS NCs was evidently alleviated by graphene matrix that not only provided a two-dimensional support to buffer the volume change, but also improved the ion migration kinetics, as corroborated by superior rate capability.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 296〈/p〉 〈p〉Author(s): Y.F. Liang, Y. Xia, S.Z. Zhang, X.L. Wang, X.H. Xia, C.D. Gu, J.B. Wu, J.P. Tu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A compositive synthesis of gel polymer electrolytes by blending poly(propylene carbonate) (PPC) into poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) as a polymer host is proposed. The blending polymer is produced by a facile solution casting method and ester groups of PPC are successful introduced into PVDF-HFP. The gel polymer electrolyte displays an excellent ion conductivity of 1.18 × 10〈sup〉−3〈/sup〉 S cm〈sup〉−1〈/sup〉, broad electrochemical window up to 4.8 V (vs. Li/Li〈sup〉+〈/sup〉) and outstanding electrochemical stability within rechargeable lithium batteries at room temperature. The improvement of ion conductivity is attributed to the decrease of polymer crystallizability and the increase of micro pores. The strategy of blending is promising for the modification of PVDF-HFP electrolyte and foreground application in next-generation solid energy conversion devices.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 20 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 297〈/p〉 〈p〉Author(s): Mariana Spodaryk, Kun Zhao, Jie Zhang, Emad Oveisi, Andreas Züttel〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The electrochemical reduction of CO〈sub〉2〈/sub〉 to higher hydrocarbons is a very challenging process that has high potential for the storage of large amounts of renewable energy with a high gravimetric and volumetric energy density. The distribution of hydrocarbons from the electrocatalytic reduction of CO〈sub〉2〈/sub〉 is primarily determined by the interaction of the cathode material with the CO〈sub〉2〈/sub〉 in the electrolyte. While the research on the electrochemical CO〈sub〉2〈/sub〉 reduction focuses on the cathode metal and surface structure of the metals, recently evidence was found that the metal itself may not be the active species but rather the product formed from the metal and CO〈sub〉2〈/sub〉. In this paper, we report about the synthesis, catalytic activity and selectivity of nanostructured metal carbonate, i.e. malachite, as a highly active catalyst for the electrochemical synthesis of C2 hydrocarbons. These first results obtained on Cu〈sub〉2〈/sub〉(OH)〈sub〉2〈/sub〉CO〈sub〉3〈/sub〉 nanorod-structured “trees” show that carbonate, not the pure metal, is the active catalytic species. This new catalyst favors the production of ethylene (C〈sub〉2〈/sub〉H〈sub〉4〈/sub〉) and ethane (C〈sub〉2〈/sub〉H〈sub〉6〈/sub〉) with significantly higher Faradaic efficiency than that of the pure Cu surface.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 20 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 297〈/p〉 〈p〉Author(s): Yejun Li, Chengan Liao, Kewei Tang, Ning Zhang, Weihong Qi, Haipeng Xie, Jun He, Kai Yin, Yongli Gao, Chundong Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Black phosphorus (BP), a new rediscovered 2-dimensional material, has gained enormous attention in the field of electrocatalysis, particularly for oxygen evolution reactions. However, its easily being oxidized nature and the bulk crystal structure restricts sufficient active sites, which severely hinders its potential applications in catalysis. Herein, BP nanosheets are prepared and deposited with Co(OH)〈sub〉2〈/sub〉 nanosheets to construct the Co(OH)〈sub〉2〈/sub〉/BP interfaces. Owing to the high Fermi level of Co(OH)〈sub〉2〈/sub〉 than that of BP, the electrons are transferred initiatively from Co(OH)〈sub〉2〈/sub〉 to BP, affording remarkable oxygen evolution reaction performance with an overpotential of 276 mV at a current density of 10 mA cm〈sup〉−2〈/sup〉. Moreover, the potentiostatic tests present decent electrocatalytic stability of the synthesized Co(OH)〈sub〉2〈/sub〉/BP nanosheets. It is further anticipated that engineering the interface towards manipulating the charge density on BP surface and/or interface by depositing other kind of catalysts could be a straightforward strategy to design outstanding hybrid electrocatalysts.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0013468618326550-fx1.jpg" width="227" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 297〈/p〉 〈p〉Author(s): Sun Jie, Ming Ting-yun, Qian Hui-xuan, Li Qi-song〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, copper-tin (Cu-Sn) alloy coating was prepared in 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) using electrodeposition method. The electrochemical behaviors of different electrolytes and the electrodeposition reversibility of Cu-Sn alloy were studied using cyclic voltammetry (CV). The electro-crystallization mechanism was investigated using chronoamperometry at different step potentials on glassy carbon (GC) electrode. The micromorphology and phase composition of Cu-Sn alloy coatings were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed a new reduction peak located at −0.50 ∼ −1.00 V, which belonged to Cu-Sn co-deposition. The reduction of Cu-Sn alloy in this system was an irreversible process. The electro-crystallization of Cu-Sn alloy followed the three-dimensional instantaneous nucleation. The results for micro-morphologies showed that, when the potential is changed, different microstructures can be formed, whereas the morphology changed from snow-like to cypress leaf-like shape. The results for phase composition showed that Cu-Sn alloy coating at different electrodeposition potentials consisted of pure cubic system Cu〈sub〉13.7〈/sub〉Sn phase. Additionally, the Cu-Sn alloy deposition from [BMIM]Cl system showed a preferred orientation on (220) crystallographic plane, which is different from the standard card.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 296〈/p〉 〈p〉Author(s): G.B. Melle, E.G. Machado, L.H. Mascaro, E. Sitta〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The search for greener energy sources has led to the development of biodiesel. One of its by-product, glycerol, is usually converted into more valuable products by organic synthesis or homogeneous catalysis. There is still room for the research on converting this molecule by means of an electrolytic or fuel cell - for that goal, a deeper understanding of the process and its variables is desirable. This work aims at describing the role of mass transport at the glycerol electro-oxidation on polycrystalline platinum in acidic media. We found that at a proper condition, a new faradaic process is observable in the cyclic voltammetry at ∼0.55 V, regarding the oxidation of glycerol at lower potentials. By means of a numerical experiment it is proposed that a soluble intermediate, namely glyceraldehyde, is the main actor in the inhibition of the process and that its removal, by the electrode rotation, yields a less poisoned surface. The results presented suggest that the aim for electrolytic or fuel cells should be the development of catalysts less active for glyceraldehyde and that the mass transport is a key factor in designing those devices.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 219〈/p〉 〈p〉Author(s): Nor Azura Sulong, Mohd Talib Latif, Mazrura Sahani, Md Firoz Khan, Muhammad Fais Fadzil, Norhayati Mohd Tahir, Noorlin Mohamad, Nobumitsu Sakai, Yusuke Fujii, Murnira Othman, Susumu Tohno〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study aimed to determine the distribution and potential health risks of polycyclic aromatic hydrocarbons (PAHs) in PM〈sub〉2.5〈/sub〉 collected in Kuala Lumpur during different monsoon seasons. The potential sources of PM〈sub〉2.5〈/sub〉 were investigated using 16 priority PAHs with additional of biomass tracers namely levoglucosan (LV), mannosan (MN) and galactosan (GL). This study also investigated the cytotoxic potential of the extracted PAHs towards V79-4 cells. A high-volume air sampler (HVS) was used to collect PM〈sub〉2.5〈/sub〉 samples for 24 h. PAHs were extracted using dichloromethane (DCM) while biomass tracers were extracted by a mixture of DCM/methanol (3:1) before analysis with gas chromatography-mass spectrometry (GC-MS). The cytotoxicity of the PAHs extract was determined by assessing the cell viability through the reduction of tetrazolium salts (MTT). The results showed that the total mean ± SD concentrations of PAHs during the southwest (SW) and northeast (NE) monsoons were 2.51 ± 0.93 ng m〈sup〉−3〈/sup〉 and 1.37 ± 0.09 ng m〈sup〉−3〈/sup〉, respectively. Positive matrix factorization (PMF) using PAH and biomass tracer concentrations suggested four potential sources of PM〈sub〉2.5〈/sub〉; gasoline emissions (29.1%), natural gas and coal burning (28.3%), biomass burning (22.3%), and diesel and heavy oil combustion (20.3%). Health risk assessment showed insignificant incremental lifetime cancer risk (ILCR) of 2.40E-07 for 70 years of exposure. MTT assay suggested that PAHs extracts collected during SW monsoon have cytotoxic effect towards V79-4 cell at the concentrations of 25 μg mL〈sup〉−1〈/sup〉, 50 μg mL〈sup〉−1〈/sup〉, 100 μg mL〈sup〉−1〈/sup〉 whereas non-cytotoxic effect was observed on the PAHs sample collected during NE monsoon.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518323026-fx1.jpg" width="413" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 218〈/p〉 〈p〉Author(s): Jiu-Qiang Xiong, Sanjay Govindwar, Mayur B. Kurade, Ki-Jung Paeng, Hyun-Seog Roh, Moonis Ali Khan, Byong-Hun Jeon〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A comprehensive ecotoxicological evaluation of a sulfamethazine (SMZ) and sulfamethoxazole (SMX) mixture was conducted using an indicator microalga, 〈em〉Scenedesmus obliquus〈/em〉. The toxicological effects of this mixture were studied using microalgal growth patterns, biochemical characteristics (total chlorophyll, carotenoid, carbohydrate, fatty acid methyl ester), and elemental and Fourier-transform infrared spectroscopy analyses. The 96-h half maximal effective concentration (EC〈sub〉50〈/sub〉) of the SMZ and SMX mixture was calculated to be 0.15 mg L〈sup〉−1〈/sup〉 according to the dose-response curves obtained. The chlorophyll content decreased with elevated SMZ and SMX concentrations, while the carotenoid content initially increased and then decreased as concentration raised. The unsaturated fatty acid methyl esters (FAMEs) content was enhanced with higher SMZ and SMX concentrations, while that of saturated FAMEs simultaneously decreased due to SMZ and SMX stress. Elemental analyses showed an improved percentage of nitrogen and sulfur in the microalgal biomass as SMZ and SMX concentrations increased. The microalga 〈em〉S. obliquus〈/em〉 was shown to biodegrade the chemicals tested and removed 31.4–62.3% of the 0.025–0.25 mg SMZ L〈sup〉−1〈/sup〉 and 27.7–46.8% of the 0.025–0.25 mg SMX L〈sup〉−1〈/sup〉 in the mixture after 12 days of cultivation. The greater biodegradation observed at higher SMZ and SMX concentrations indicates that microalgal degradation of SMZ and SMX could act as an efficient adaptive mechanism to antibiotics.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 217〈/p〉 〈p〉Author(s): Saeed Ahmad Asad, Muhammad Farooq, Aftab Afzal, Helen West〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Heavy metal contamination in the environment is a global threat which accelerated after the industrial revolution. Remediation of these noxious elements has been widely investigated and multifarious technologies have been practiced for many decades. Phytoremediation has attracted much attention from researchers. Under this technology, heavy metal hyperaccumulator plants have been extensively employed to extract extraordinary concentrations of heavy metals but slow growth, limited biomass and stresses caused by heavy metals imperil the efficiency of hyperaccumulators. Plant growth promoting rhizobacteria (PGPR) can help overcome/lessen heavy metal-induced adversities. PGPR produce several metabolites, including growth hormones, siderophores and organic acids, which aid in solubilization and provision of essential nutrients (e.g. Fe and Mg) to the plant. Hyperaccumulator plants may be employed to remediate metal contaminated sites. Use of PGPR to enhance growth of hyperaccumulator plant species may enhance their metal accumulating capacity by increasing metal availability and also by alleviating plant stress induced by the heavy metals. Combined use of hyperaccumulator plants and PGPR may prove to be a cost effective and environmentally friendly technology to clean heavy metal contaminated sites on a sustainable basis. This review discusses the current status of PGPR in improving the growth and development of hyperaccumulator plants growing in metal contaminated environments. The mechanisms used by these rhizosphere bacteria in increasing the availability of heavy metals to plants and coping with heavy metal stresses are also described.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 218〈/p〉 〈p〉Author(s): Sayka Jahan, Vladimir Strezov〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study seaweeds (〈em〉Ecklonia radiata〈/em〉) from six major sea ports of NSW, Australia were used as a bioindicator to assess the distribution and levels of trace elements accumulation in the ports compared to the background ecosystem. Bioconcentration ratio (BCR), biota sediment accumulation factor (BSAF), enrichment factor, multivariate statistical analysis and hierarchical cluster analysis were used to identify trace elements contamination. The results illustrate BCRs of Al, Fe, Mn, Zn, Pb, Cu, As and Ba in 〈em〉E. radiata〈/em〉 whereas the BASFs portray boron enrichment in all sea ports along with bioaccumulation of As in Port Jackson and Pb in Port Botany. However, trace elements variations between studied and background locations was found to be significant for Port Kembla and Newcastle. The principal component analysis result explained four principal groups with 76.25% cumulative variance. Cluster analysis was further performed to detect major groups of elements and sites to portray interconnection between the contaminants and the locations.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518322690-fx1.jpg" width="250" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 218〈/p〉 〈p〉Author(s): S.A. Durward-Akhurst, N.E. Schultz, E.M. Norton, A.K. Rendahl, H. Besselink, P.A. Behnisch, A. Brouwer, R.J. Geor, J.R. Mickelson, M.E. McCue〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Equine Metabolic Syndrome (EMS) is characterized by abnormalities in insulin regulation, increased adiposity and laminitis, and has several similarities to human metabolic syndrome. A large amount of environmental variability in the EMS phenotype is not explained by commonly measured factors (diet, exercise, and season), suggesting that other environmental factors play a role in EMS development. Endocrine disrupting chemicals (EDCs) are associated with metabolic syndrome and other endocrine abnormalities in humans. This led us to hypothesize that EDCs are detectable in horse plasma and play a role in the pathophysiology of EMS. EDCs acting through the aryl hydrocarbon and estrogen receptors, were measured in plasma of 301 horses from 32 farms. The median (range) TEQ (2,3,7,8-TCDD equivalent) and EEQ (17β-estradiol equivalent) were 19.29 pg/g (0.59–536.36) and 10.50 pg/ml (4.35–15000.00), respectively. TEQ was negatively associated with plasma fat extracted and batch analyzed. EEQ was positively associated with pregnancy and batch analyzed, and negatively associated with being male and superfund score ≤100 miles of the farm. Of particular interest, serum glucose and insulin, glucose and insulin post oral sugar challenge, and leptin concentrations were associated with EEQ, and serum triglyceride concentration was associated with TEQ. Overall, we demonstrated that EDCs are present in the plasma of horses and may explain some of the environmental variability in measured EMS phenotypes. This is the first example of EDCs being associated with clinical disease phenotype components in domestic animals.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 218〈/p〉 〈p〉Author(s): Bo Wang, Yuanyuan Guo, Mengyue Zhao, Baikun Li, Yongzhen Peng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Energy savings via achieving the reduction of aeration and excess sludge is required to realize energy self-sufficiency in wastewater treatment plants. A novel partial nitritation + simultaneous anammox denitrification and sludge fermentation (PN + SADF) process was operated for nearly two years, during which simultaneous energy-efficient nitrogen removal and waste activated sludge (WAS) reduction was achieved, with a stable nitrogen removal efficiency of 80% and external WAS reduction of 40%–50%. In the PN reactor, presence of ammonia oxidizing bacteria and absence of nitrite oxidizing bacteria ensured the stable nitritation. In the SADF reactor, nitrogen was removed via denitrification and anammox by using nutrients and organics released from WAS solubilization. Comparable performance of the SADF reactor at ambient temperature (12–32 °C) to that at 30 °C indicated a practical application potential for the PN + SADF process. An initial estimation of a full-scale PN + SADF process serving a population of 100000 showed that it could save economy and energy in comparison with conventional nitrification-denitrification process. Despite some challenges in implementation, this paper highlights the potential implication for sustaining mainstream nitritation-anammox towards energy-efficient operation with excess sludge reutilization.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518322768-fx1.jpg" width="280" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 297〈/p〉 〈p〉Author(s): Weilu Yang, Minghua Zhou, Nihal Oturan, Yawei Li, Pei Su, Mehmet A. Oturan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Degradation of the herbicide 2,4-dichlorophenoxiacetic acid (2,4-D) in aqueous solutions has been studied by electrochemical oxidation process using N-doped graphene modified graphite felt cathode with ammonium nitrate as nitrogen source. The graphene was obtained via electrochemically exfoliated method (EEGr). Different ratios of EEGr/ammonium nitrate (1:0, 1:1, 1:3, 1:7) modified cathodes (N0-EEGr-GF, N1-EEGr-GF, N3-EEGr-GF, N7-EEGr-GF) were explored with electrochemical characterizations, and it was verified that N1-EEGr had the most significant catalytic performance for accelerating the activation of in-situ generated H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 into hydroxyl radicals. The effects of operating parameters such as applied potential, solution pH and initial concentration of 2,4-D on the degradation efficiency with N1-EEGr-GF were investigated. A fairly high mineralization rate (88%) was attained at pH 7 after 480 min electrolysis of 20 mg L〈sup〉−1〈/sup〉2,4-D solution. The N-doped graphene as catalyst was found to be more efficient in degradation performance compared with the unmodified graphite felt cathode. The electrochemical advanced oxidation process using this modified cathode allows extension of the working pH range compared to electro-Fenton process which is optimal at pH 3. Finally, a plausible pathway for 2,4-D mineralization was proposed according to the identified intermediated products.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S001346861832680X-egi10N9VHGBJWS.jpg" width="276" alt="Image 109" title="Image 109"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 218〈/p〉 〈p〉Author(s): Cristina Daniela Possenti, Giulia Poma, Saskia Defossé, Manuela Caprioli, Beatrice De Felice, Andrea Romano, Nicola Saino, Adrian Covaci, Marco Parolini〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Triclosan (TCS) is an antimicrobial agent used in diverse personal care products that is considered as an emerging contaminant of both aquatic and terrestrial ecosystems. Although TCS aquatic ecotoxicity is well known, information on the presence and effects on terrestrial organisms is still scarce. This study was aimed at exploring the embryotoxicity of TCS to the yellow-legged gull (〈em〉Larus michahellis〈/em〉) induced by the 〈em〉in-ovo〈/em〉 injection of 150 ng TCS/g egg weight. Effects of TCS on embryo morphological traits (i.e. body mass, tarsus length and head size). Moreover, oxidative and genetic effects were assessed in the embryo liver, by measuring the amount of reactive oxygen species (ROS), the activity of antioxidant (superoxide dismutase and catalase) and detoxifying (glutathione 〈em〉S〈/em〉-transferase - GST) enzymes, the levels of lipid peroxidation and DNA fragmentation. After the injection, the concentration of TCS measured in the yolk of unincubated eggs (159 ± 35 ng/g wet weight, ww) was close to the expected concentration. Triclosan was found in residual yolk (2.9 ± 1.1 ng/g ww), liver (2.3 ± 1.1 ng/g ww) and brain (0.2 ± 0.1 ng/g ww) of embryos soon before hatching. Triclosan did not significantly affect embryo morphological traits, while it increased ROS levels and promoted GST activity, inducing the onset of both oxidative and genetic damage. This study demonstrated, for the first time in a wild euriecious bird species with mixed habits, that TCS can be maternally transferred to developing embryos, representing a potential threat for offspring.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S004565351832294X-fx1.jpg" width="154" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 298〈/p〉 〈p〉Author(s): Ze Chai, Chuanhai Jiang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The corrosion behavior of Ni〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Co〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Cu nanocrystalline coatings in neutral salt environments was systematically investigated by potentiodynamic polarization, linear polarization, electrochemical impedance spectroscopy, and long-term salt spray tests. The electrodeposited ternary coatings were Ni-based solid solution alloys that contained markedly different contents of Co and Cu. Greater Co and Cu contents strongly reduced the polarization and charge-transfer resistance of the coatings, thus decreasing their corrosion resistance in neutral NaCl solutions. In salt spray tests, the initial porous corrosion product film on the Co-/Cu-poor coating evolved into a compact film that finally grew to cover the coating surface, while such morphological transition was absent on the Co-/Cu-rich coating, where the formed film showed a continuous deterioration in its initial porous structure. Abundant Co-/Cu-substituted α-Ni(OH)〈sub〉2〈/sub〉 might grow to form the primary compact films that could coalesce and thicken as corrosion was suppressed. A large amount of Cu(OH)〈sub〉2〈/sub〉 together with high corrosion rates might be detrimental to the formation of compact films. A mechanism of the formation of the corrosion product films was proposed based on the corrosion characteristics of the ternary system and detailed corrosion product film analysis.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 220〈/p〉 〈p〉Author(s): Yuliya E. Tyutereva, Petr S. Sherin, Marina V. Parkhats, Zizheng Liu, Jing Xu, Feng Wu, Victor F. Plyusnin, Ivan P. Pozdnyakov〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The mechanism of direct UV photolysis of p-arsanilic acid (p-ASA), a widely used veterinary drug, was revised by means of laser flash photolysis coupled with high resolution liquid chromatography – mass spectrometry (LC-MS). None of p-ASA triplet state or singlet oxygen was found to directly participate in the photodegradation of p-ASA as it was assumed in previous works. Here we demonstrate that the main primary photoprocess is a monophotonic ionization (ϕ〈sub〉ion〈/sub〉〈sup〉266nm〈/sup〉 = 0.032) leading to the formation of hydrated electron and corresponding anilinyl cation radical. These primary species react with dissolved oxygen yielding secondary reactive oxygen species. The final organic photoproducts, such as aminophenol and different dimeric products, originate from various reactions between these secondary species. The generation of inorganic arsenic, both As(V) and As(III), was also observed in agreement with previous works. For the first time we report the quantum yield of p-ASA photodegradation, which decreases from 0.058 to 0.035 with the excitation wavelength from 222 to 308 nm.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 220〈/p〉 〈p〉Author(s): Mark G. Cantwell, David R. Katz, Julia C. Sullivan, Matthew Lyman〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Urban estuaries receive large volumes of effluents from municipal wastewater treatment facilities containing numerous contaminants, such as pharmaceuticals residues. Water was sampled for 16 highly prescribed pharmaceuticals at 17 sites along the Long Island Sound (LIS) estuary located in the Northeastern U.S. Pharmaceutical concentrations were highest in western LIS, ranging from non-detect to 71 ng L〈sup〉−1〈/sup〉 and declining steadily eastward, while river samples from four major tributaries ranged from non-detect to 83 ng L〈sup〉−1〈/sup〉. Two tracers, sucralose and caffeine, accurately predicted pharmaceutical behavior in LIS while only sucralose was effective at the river sites. Sucralose also tracked well with the salinity gradient in LIS, exhibiting conservative behavior along the transect. Attenuation factors were determined for measurable pharmaceuticals and compared against sucralose to estimate the magnitude of decline in concentrations that may be attributable to in situ degradation and partitioning. The results demonstrate sucralose's effectiveness as a tracer of wastewater-borne contaminants under estuarine conditions.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 220〈/p〉 〈p〉Author(s): Dejun Wan, Lei Song, Xin Mao, Jinsong Yang, Zhangdong Jin, Handong Yang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Historical records of heavy metals from remote areas are important for assessing temporal pollution trends of the regional atmosphere. Based on comparison analyses of heavy metals, Pb isotopes, and total carbon in sediment cores from two relatively remote lakes on the southeast Mongolian Plateau, atmospheric heavy metal pollution trends during ∼1900–2016 were reconstructed. The current anthropogenic fluxes of Zn, Cd and Pb in the region are 11.7, 0.104 and 2.44 mg m〈sup〉−2〈/sup〉 yr〈sup〉−1〈/sup〉, respectively, close to those in Lake Sayram in West China, but lower than most other records in China. Anthropogenic metal fluxes and 〈sup〉206〈/sup〉Pb/〈sup〉207〈/sup〉Pb ratios suggest that (1) before ∼1950 atmospheric metal pollution was negligible in the region; (2) since ∼1950, the pollution became detectable but was relatively slight until ∼1980, corresponded with the beginning of socio-economic development after the foundation of China in 1949 and the rapid development after the Reform and Opening-up in 1978; and (3) since ∼2000, atmospheric Pb stopped increasing because of the phasing out of leaded gasoline. Based on comparison and fitting analyses with other sediment records, a similar four-stage evolution picture of atmospheric heavy metals in China over the last century was uncovered. This study indicates rapid increase trends of atmospheric heavy metals in China since ∼1980 associated with economic development.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 220〈/p〉 〈p〉Author(s): Fujun Ma, Xuemei Han, Lihui An, Kun Lei, Hongli Qi, Gerald A. LeBlanc〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The modes of action by which putative endocrine disrupting chemicals (EDCs) elicit toxicity in mollusks remains unclear due to our limited understanding of the molluscan endocrine system. We identified and partially characterised the estrogen receptor (ER) of the mollusk 〈em〉Parafossarulus striatulus.〈/em〉 The full-length cDNA of the ER of 〈em〉P. striatulus〈/em〉 (〈em〉ps〈/em〉ER) was isolated and found to have an ORF of 1386 bp which corresponded to 461 amino acids. Phylogenetic analysis revealed that 〈em〉ps〈/em〉ER is an orthologue of ER of other mollusks. Moreover, the DNA-binding domain, ligand-binding domain, P-box, D-box, and AF2 domain were also identified in 〈em〉ps〈/em〉ER. Exposure of females and males to 17〈em〉β〈/em〉-estradiol (E2, 100 ng/L) for 24 h and 72 h did not alter 〈em〉ps〈/em〉ER transcription, but exposure to 17〈em〉α〈/em〉-methyltestosterone (MT, 100 μg/L) for 72 h significantly decreased ER transcription in females only (〈em〉p〈/em〉 〈 0.05). 〈em〉ps〈/em〉ER transcription was surveyed in males and females seeded in different regions in Taihu Lake, China. 〈em〉ps〈/em〉ER transcription were elevated among females and males maintained at site ML. This elevation was statistically significant (〈em〉p〈/em〉 〈 0.05) among male snails as compared to snails held at the more pristine site of SZ. This was different to the results from lab, implying that some unknown chemicals or other environmental factors in field could affect 〈em〉ps〈/em〉ER transcription level in snails. Furthermore, females and males held at site ML also exhibited a significant elevation in vitellogenin transcription as compared to snails held at site SZ, suggesting that vitellogenin production may be directly regulated by 〈em〉ps〈/em〉ER or co-regulated with 〈em〉ps〈/em〉ER in this species.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518325177-fx1.jpg" width="282" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 220〈/p〉 〈p〉Author(s): Afzal Ahmed Dar, Xinghao Wang, Siyuan Wang, Jiali Ge, Asam Shad, Fuxun Ai, Zunyao Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Ozonation has been identified effective technique to degrade phenolic compounds, and production of intermediate dimers are major threat. In this study, we systematically investigated the degradation of Pentabromophenol (PBP) in an aqueous medium by using two different ozone generators (sources: air and water). We studied various factors that influenced the degradation kinetics of PBP, including the pH (7.0, 8.0, and 9.0), humic acid (HA) and anions (Cl〈sup〉−〈/sup〉, SO〈sub〉4〈/sub〉〈sup〉2−〈/sup〉, NO〈sub〉3〈/sub〉〈sup〉−〈/sup〉, and HCO〈sub〉3〈/sub〉〈sup〉−〈/sup〉). PBP was efficiently degraded within 5 min (O〈sub〉3〈/sub〉 source: water) and 45 min (O〈sub〉3〈/sub〉 source: air) at pH 8.0 maintained by phosphate buffer. Reaction kinetics revealed 17 b y-products with five possible pathways, including dimers with their isomers and lower bromophenols. Furthermore, the frontier molecular orbital theory was employed to confirm the proposed ozonation pathways, including the breakage of the C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O bond at C〈sub〉5〈/sub〉 and C〈sub〉4〈/sub〉 positions, and the cleavage of the C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉C bond at C〈sub〉3〈/sub〉 and C〈sub〉6〈/sub〉 position. Product P5, P14 (hydroxyl-nonabromophenyl ether) and P15 (dihydroxyl-octabromophenyl ether) were identified with isomers. Ecological Structure Activity Relationships toxicity assessment resulted into the conversion of highly toxic PBP (acute toxicity: LC〈sub〉50〈/sub〉 = 0.11 mg L〈sup〉−1〈/sup〉 for fish, LC〈sub〉50〈/sub〉 = 0.124 mg L〈sup〉−1〈/sup〉 for daphnia, and EC〈sub〉50〈/sub〉 = 0.118 mg L〈sup〉−1〈/sup〉 for green algae) to less harmful products aside from dimers. P14 (acute toxicity: LC〈sub〉50〈/sub〉 = 1.04 × 10〈sup〉5〈/sup〉) found to be more toxic as compare to PBP. From these findings, we concluded that ozonation is an effective and ideal process for PBP degradation.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 220〈/p〉 〈p〉Author(s): Lur Epelde, Anders Lanzén, Iker Martín, Susana Virgel, Iker Mijangos, Gerardo Besga, Carlos Garbisu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Technosols can be used to rehabilitate degraded land and reuse wastes. Ideally, these newly formed soils should also fulfil the main soil functions. In this study, initially, we characterized the physicochemical and microbial properties of different formulations and their ingredients (i.e., dirt from a waste recovery plant, recycled bentonite, sewage sludge). When these technosols were then used for the rehabilitation of a quarry, the evolution of such properties was monitored for three consecutive years. Physicochemical and microbial properties were compared to those of a reference soil from a nearby forest. Diversity and composition of prokaryotes and eukaryotes were determined using 16S and 18S rRNA amplicon sequencing. Three years after establishment, as much as 78.8% and 63.9% of the prokaryotic and eukaryotic orders, respectively, were shared between the technosols and the reference forest soil. Although technosols initially showed lower values of CO〈sub〉2〈/sub〉 emission, compaction and functional diversity (Biolog EcoPlates™), at the end of the study these values were similar to those observed in the reference forest soil. It was concluded that the microbiota of the studied technosols resembles that of the nearby forest soil after just three years of establishment.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518325050-fx1.jpg" width="264" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 220〈/p〉 〈p〉Author(s): Barbara Kubickova, Petra Laboha, Jan-Peter Hildebrandt, Klara Hilscherová, Pavel Babica〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Anthropogenic eutrophication of freshwater bodies increases the occurrence of toxic cyanobacterial blooms. The cyanobacterial toxin cylindrospermopsin (CYN) is detected in the environment with increasing frequency, driving the scientific effort to assess emerging health risks from CYN-producing blooms. Oral exposure to CYN results primarily in hepatotoxicity. Nevertheless, extrahepatic manifestations of CYN toxicity have been reported. Furthermore, cyanotoxins have been detected in aerosols and dust particles, suggesting potential toxic effects in the respiratory tract. To assess the susceptibility of airway epithelia towards cyanotoxins, monolayers of immortalized human bronchial epithelial cells HBE1 and 16HBE14o- were exposed to a concentration range of 0.1–10 μM CYN. Cytotoxic endpoints were assessed as morphologic alterations, resazurin reduction capacity, esterase activity, neutral red uptake, and by impedimetric real-time cell analysis. Depending on the endpoint assessed, EC〈sub〉50〈/sub〉 values ranged between 0.7 and 1.8 μM (HBE1) and 1.6–4.8 μM (16HBE14o-). To evaluate alterations of other cellular events by subcytotoxic concentration of CYN (1 μM), phosphorylation of mitogen-activated protein kinases ERK and p38 was determined. Only a slight increase in p38 phosphorylation was induced by CYN in HBE1 cell line after 48 h, while activities of both ERK1/2 and p38 gradually and significantly increased in 16HBE14o- cells during 8–48 h exposure. This study suggests possible hazards of inhalation CYN exposures, which may severely impact the integrity of airway epithelia and epithelial cell signaling. Further research of CYN-induced toxicity and underlying mechanisms is needed, as well as more data on environmental concentrations of cyanotoxins in aerosols for exposure assessment.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518324925-fx1.jpg" width="357" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 298〈/p〉 〈p〉Author(s): Katerina Govatsi, Andreas Seferlis, Spyros N. Yannopoulos, Stylianos G. Neophytides〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In the present study, based on potentiodynamic and potentiostatic measurements as well on specific surface area analysis data we present a detailed study on the photoelectrochemical properties of ZnO nanorod (NR) arrays aiming to shed light on the photo-electrokinetics of oxygen evolution reaction (OER) on the ZnO surface interfaced with 0.1 M NaOH aqueous solution. The faradaic selectivity for the oxygen evolution is around 70% and takes place on the side-wall (e.g. 110) planes of the NRs, while H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 is produced on the (001) polar planes, which appear to be 3–4 times more reactive than the side-wall (110) planes. By the use and the kinetic analysis of potentiodynamic experiments it has been inferred that the OER mechanism involves two active sites on the (110) surface: (I) the surface Zn atoms where OH〈sup〉−〈/sup〉 are being discharged and adsorbed electrochemically 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mrow〉〈mi〉O〈/mi〉〈msubsup〉〈mrow〉〈mi〉H〈/mi〉〈/mrow〉〈mrow〉〈mi〉a〈/mi〉〈mi〉d〈/mi〉〈/mrow〉〈mrow〉〈mi〉Z〈/mi〉〈mi〉n〈/mi〉〈/mrow〉〈/msubsup〉〈/mrow〉〈/math〉 and (II) the photo-induced oxygen vacancies where the former species migrate and are adsorbed as 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.gif" overflow="scroll"〉〈mrow〉〈mi〉O〈/mi〉〈msubsup〉〈mrow〉〈mi〉H〈/mi〉〈/mrow〉〈mrow〉〈mi〉a〈/mi〉〈mi〉d〈/mi〉〈/mrow〉〈mrow〉〈mi〉V〈/mi〉〈/mrow〉〈/msubsup〉〈/mrow〉〈/math〉 and evolved as O〈sub〉2〈/sub〉 under the effect of incident radiation. The transient kinetic analysis of the potentiodynamic measurements resulted in the determination of the electrokinetic parameters (Tafel slope 〈em〉(b)〈/em〉, symmetry factors 〈em〉(β)〈/em〉 and exchange current densities 〈em〉(I〈/em〉〈sub〉〈em〉o〈/em〉〈/sub〉〈em〉)〈/em〉) of the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mrow〉〈mi〉O〈/mi〉〈msubsup〉〈mrow〉〈mi〉H〈/mi〉〈/mrow〉〈mrow〉〈mi〉a〈/mi〉〈mi〉d〈/mi〉〈/mrow〉〈mrow〉〈mi〉Z〈/mi〉〈mi〉n〈/mi〉〈/mrow〉〈/msubsup〉〈/mrow〉〈/math〉 and 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.gif" overflow="scroll"〉〈mrow〉〈mi〉O〈/mi〉〈msubsup〉〈mrow〉〈mi〉H〈/mi〉〈/mrow〉〈mrow〉〈mi〉a〈/mi〉〈mi〉d〈/mi〉〈/mrow〉〈mrow〉〈mi〉V〈/mi〉〈/mrow〉〈/msubsup〉〈/mrow〉〈/math〉 species, thus providing significant insight as of their binding energies and their reactivity on the ZnO surface. The turnover frequency at the maximum of the applied bias photoconversion efficiency (ABPE) for the production of one molecule of O〈sub〉2〈/sub〉 is 0.35 s〈sup〉−1〈/sup〉.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0013468618327890-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 298〈/p〉 〈p〉Author(s): Yaqin Zhao, Xiaofang Cui, Jing yang, Lu Yu, Binsheng Yang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The interaction of 〈em〉Yersinia pestis〈/em〉 (YpHmuT) with Fe center on hemin (ferric form) or heme (ferrous form) was investigated by differential pulse voltammetry (DPV), cyclic voltammetry (CV), square wave voltammograms (SWV), electrochemical impedance spectroscopy (EIS) and spectra. Electrochemical signals of hemin/heme were strongly influenced by virtue of interacting with YpHmuT. The 2:1 stoichiometric ratio of the hemin or heme to YpHmuT was confirmed. YpHmuT binds to ferric hemin with pentacoordinate and high-spin and binds to ferrous heme with low-spin. Our findings may provide useful data for understanding biological processes of hemin transportation in 〈em〉Yersinia pestis〈/em〉.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Square wave voltammograms of hemin〈sub〉2〈/sub〉-YpHmuT (a) and heme〈sub〉2〈/sub〉-YpHmuT (b). Hemin〈sub〉2〈/sub〉-YpHmuT: green: YpHmuT backbone (PDB: 〈a href="http://www.rcsb.org/pdb/explore.do?structureId=3NU1" target="_blank"〉3NU1〈/a〉), red: hemin a, blue: hemin b; Heme〈sub〉2〈/sub〉-YpHmuT: green: YpHmuT backbone (PDB: 〈a href="http://www.rcsb.org/pdb/explore.do?structureId=3NU1" target="_blank"〉3NU1〈/a〉), orange: heme a, pink: heme b.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0013468618328196-fx1.jpg" width="257" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 298〈/p〉 〈p〉Author(s): Qian Lu, Yang Sun, Kaiming Liao, Xiaohong Zou, Ikutaro Hamada, Wei Zhou, Meng Ni, Zongping Shao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Poor electrical conductivity of sulfur, sluggish redox kinetics, dissolution of intermediate polysulfides, and expansion in volume upon cycling are the main drawbacks that hamper the practical application of Li-S batteries. By taking advantages of the high conductivity and favorable catalytic activity of RuO〈sub〉2〈/sub〉, we design a 3D carbon nanotube film with embedded RuO〈sub〉2〈/sub〉 nanoparticles as a freestanding type of chemisorptive and catalyst-like cathode for Li-S batteries, which can be facilely prepared by a surfactant-assisted vacuum infiltration method. Both experimental and theoretical results reveal the excellent capability of RuO〈sub〉2〈/sub〉 for anchoring polysulfides and accelerating the kinetics of polysulfides catalytic redox reactions. Besides, the 3D freestanding cathode is beneficial to overcoming pulverization during volume changes, especially for long-term cycling. At a high areal sulfur loading of 2 mg cm〈sup〉−2〈/sup〉, favorable initial capacities of 750 and 1060 mA h g〈sup〉−1〈/sup〉 respectively at 2 and 0.5 C are achieved. More attractively, the capacity after 1000 cycles maintains 405 mA h g〈sup〉−1〈/sup〉 at 0.5 C with a loss in capacity of only 0.06% per cycle. Additionally, such freestanding cathode allows the batteries to be tested under various bending stages, hence encouraging more research works on fabrication of other 3D nanostructure families as high-performance cathodes for Li-S batteries.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈strong〉A 3D free-standing catalyst-like cathode〈/strong〉 is designed and prepared for Li-S battery through a surfactant-assisted infiltration approach. Favorable high-rate performances and stabilities are delivered for Li-S battery with the as-prepared cathode due to the excellent chemisorption, high conductivity and for various redox reactions of RuO〈sub〉2〈/sub〉. The 3D free-standing catalyst-like cathode provides an inspirational model for promising flexible energy storage devices.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0013468618328214-fx1.jpg" width="249" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 298〈/p〉 〈p〉Author(s): Kané Rabé, Lifen Liu, Noor Ahmed Nahyoon, Yizhen Zhang, Ahmed Mahmoud Idris〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Degradation of pollutants can be integrated with electricity generation in Photocatalytic fuel cell under light irradiation or self-powered fuel cell in the dark. In fuel cell driven by electrode reactions, the electrode reduction and oxidation transforms chemical energy in pollutants into electrical energy. In this work, Rhodamine B and coking wastewater were treated, using an efficient Z-scheme g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/Fe〈sup〉0〈/sup〉(1%)/TiO〈sub〉2〈/sub〉 as an anodic catalyst and WO〈sub〉3〈/sub〉 as a cathodic catalyst. After 100 min of reaction in a single chamber fuel cell with 10 Ω of external resistance, in 0.05 M Na〈sub〉2〈/sub〉SO〈sub〉4〈/sub〉 electrolyte, the paired stainless-steel electrodes loaded respectively with g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/Fe〈sup〉0〈/sup〉(1%)/TiO〈sub〉2〈/sub〉 and WO〈sub〉3〈/sub〉, degraded 98% Rhodamine B and generated 0.95 V cell voltage under 50 W visible-light irradiation, while removed 60% RhB and generated 0.5 V without light. To investigate the PFC performance of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/Fe〈sup〉0〈/sup〉(1%)/TiO〈sub〉2〈/sub〉 in treating real coking wastewater, at optimal pH 2, 91% chemical oxygen demand (COD) and 89% total organic carbon (TOC) were removed and generated 0.3 V cell voltage. The influence of pH on photocatalytic degradation performance and cell voltage are evaluated. The high cell voltage is attributed to the very low impedance of the g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/Fe〈sup〉0〈/sup〉(1%)/TiO〈sub〉2〈/sub〉 loaded anode. The excellent electrochemical properties of paired electrodes help in generating higher current density, due to the increased photocatalyst activity of the tridimensional catalyst as proved by electron spinning resonance spectrum, photoluminescence, and Electric Impedance Spectrum analysis.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0013468618328317-fx1.jpg" width="345" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 297〈/p〉 〈p〉Author(s): Xuemin Li, Andrew M. Colclasure, Donal P. Finegan, Dongsheng Ren, Ying Shi, Xuning Feng, Lei Cao, Yuan Yang, Kandler Smith〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Application of advanced anode and cathode materials in commercial lithium-ion batteries is attracting attention due to their high capacity. Silicon (Si)/graphite anodes and nickel (Ni)-rich lithium nickel manganese cobalt oxide with layered structures have been paired in commercial 18650 high energy density cells (∼270 Wh/kg). It is crucial to investigate the cell performance and the aging behavior of this commercial cell. In this study, we present commercial cell degradation mechanisms by comparing fresh and aged electrodes, including changes of crystal structure, morphology, elemental composition, and electrochemical properties. The quantitative analysis was done based on dV/dQ incremental capacity analysis of 18650 cells. To determine the amount of cyclable lithium ions (Li〈sup〉+〈/sup〉) and active material loss, the lithiation and delithiation capacity were compared for fresh and aged electrodes in half coin cells. Results showed that even with 5% (by mass) of Si added in the anode, cracks occurred across the anode leading to contact loss and thickening of the solid electrolyte interphase (SEI) layer. Additionally, the average fluorine (F) ratio of the aged anodes was higher compared to that of the fresh anodes. More severely, the F content on the Si aggregations on aged anodes increased to as high as 5 times that of the fresh anode, indicating SEI growth, especially on Si particles. Solid 〈sup〉7〈/sup〉Li nuclear magnetic resonance results showed no detectable Li metal deposition on the aged anode. On the cathode side, cracks on the primary particle interfaces contributed to cathode material loss, contact loss, and impedance rise. Therefore, Li〈sup〉+〈/sup〉 loss into the thickened SEI layer, particle cracking, and impedance rise are the main reasons behind cell degradation.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0013468618326781-fx1.jpg" width="283" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 298〈/p〉 〈p〉Author(s): Manavalan Vijayakumar, Duggirala Sri Rohita, Tata Narasinga Rao, Mani Karthik〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Smart adjustment of active mass loading on positive and negative electrodes, significant enhancement of energy density with long-term durability is achieved due to expand of operating potential window of the electrochemical capacitor. In the present contribution, two different carbon materials like indigenous activated carbon fibres and commercial Kuraray YP-50 carbon are utilised as electrodes and the equal/unequal mass configurations of electrochemical capacitor are systematically investigated by using 1 M tetraethylammonium tetrafluoroborate/AN as an organic electrolyte. The electrochemical performances of equal/unequal mass configurations are examined in terms of potential stability window and the durability of the electrochemical capacitor. The unequal mass configuration of carbon fibres electrodes shows 25% higher gravimetric energy density than unequal commercial YP-50 electrodes. Besides, unequal mass configuration of carbon fibres exhibit 41% higher gravimetric energy density as compared with commercial YP-50 carbon at 2.7 V as extensively reported in the literature. This result clearly explores the benefits of unequal mass configurations of electrochemical capacitor for extending the operation voltage window of organic electrolyte with long durability and this strategy enlightens the design of well-defined carbon-carbon based electrodes for commercial implementation.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Electrochimica Acta, Volume 298〈/p〉 〈p〉Author(s): Megan Longstaff, Kaitlin Gardiner, Rodion Zhuravlev, Jacob Finney, Dean A. Waldow〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Block copolymers present the ability to design solid polymer electrolytes to include both ion conductivity and structural features which may lead to improved safety in lithium ion batteries. We report a morphology study of novel block copolymer electrolytes that were synthesized using ring opening metathesis polymerization. The monomers have an oxanorbornene dicarboximide backbone where the first block has oligomeric (n = 12) ethylene oxide (OEO) side chains and the second block has phenyl side groups. The former block achieves high salt solubility, while the latter block is a structural component with a high glass transition temperature. Block copolymers have been synthesized covering a range of compositions from 38 to 70 wt % of the phenyl containing block, and have been studied neat and with bis(trifluoromethane)sulfonimide lithium salt. The resulting morphologies were investigated using atomic force microscopy and small angle X-ray scattering (SAXS). Solvent vapor annealing was found to enhance ordering in the neat copolymer thin films and the addition of salt with solvent vapor annealing further increased long range order. Cylinder and lamellar structures dominate the observed morphologies and the addition of salt increases ordering and the range block copolymer compositions with lamellar structure. SAXS results demonstrate modest ordering, reinforce the observations from AFM, and show an increase in domain size with an increase in salt concentration.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 220〈/p〉 〈p〉Author(s): Monika Nowak, Adrian Soboń, Anna Litwin, Sylwia Różalska〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, the ability of 4-〈em〉n〈/em〉-nonylphenol (4-〈em〉n〈/em〉-NP) elimination by fungal species belonging to the genus 〈em〉Metarhizium〈/em〉 was investigated. The occurrence of 35 metabolites from 4-〈em〉n〈/em〉-NP degradation was confirmed. For the first time, based on the obtained results, the 4-〈em〉n〈/em〉-NP biodegradation pathway distinctive for the genus 〈em〉Metarhizium〈/em〉 was proposed. Principal Component Analysis (PCA) indicated that despite the similar elimination pathway in all the examined 〈em〉Metarhizium〈/em〉 species, there are significant differences in the kinetics of degradation of 4-〈em〉n〈/em〉-NP. Oxidation of the terminal methyl group of the aliphatic chain leading to the formation of carboxylic acids coupled with the removal of terminal carbon is characteristic of 〈em〉M. robertsii〈/em〉 and 〈em〉M. guizhouense〈/em〉, whereas metabolites with a hydroxyl group in the distal part of the nonyl chain distinguish 〈em〉M. lepidiotae〈/em〉 and 〈em〉M. majus〈/em〉. Additionally, this study verified the participation of cytochrome P450 in the elimination of the xenobiotic by 〈em〉Metarhizium〈/em〉 as experimentally proven for 〈em〉M. robertsii〈/em〉.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 220〈/p〉 〈p〉Author(s): Marzio Invernizzi, Alessia Bellini, Riccardo Miola, Laura Capelli, Valentina Busini, Selena Sironi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The aim of this work is the evaluation and the analysis of the different chemical-physical variables that affect the emission of volatile organic compounds (VOC) and odours from passive liquid area sources inside a wind tunnel, which is typically used for emission sampling. Three different compounds (acetone, butanol and ethanol), having different volatilization properties (e.g., boiling point, solubility), were studied in solution with water at different concentrations. The following physical parameters affecting the VOC volatilization in the Wind Tunnel system were evaluated: the velocity of the air flowing through the device, in a range from 0.01 to about 0.05 m/s, and the temperature of both the liquid source and the sweep air flow, in a range from 12 °C to 42 °C. The experimental results were compared with the existing volatilization models available in literature. In most cases the proposed theoretical model predicts well the experimentally measured concentration. Some discrepancies were observed for lower velocities and also by moving from the room temperature (20 °C); and those were discussed by making some considerations about the volatilization phenomenon. Moreover, the study clearly shows that it is not the gas phase temperature that controls the emission, but the temperature of the liquid phase, due to the effect of the latter on the vapour pressure of the compound, which is the main driving force of the phenomenon.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 220〈/p〉 〈p〉Author(s): C. Lindim, D. de Zwart, I.T. Cousins, S. Kutsarova, R. Kühne, G. Schüürmann〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Surface water concentrations of 54 pharmaceuticals were predicted for seven major Swedish rivers and the Stockholm City area basins using the STREAM-EU model. These surface water concentrations were used to predict the ecotoxicological impact resulting from the exposure of aquatic organisms to this mixture of 54 pharmaceuticals. STREAM-EU model results indicated that 〈10 substances were present at median annual water concentrations greater than 10 ng/L with highest concentrations occurring mostly in the more densely populated area of the capital city, Stockholm. There was considerable spatial and temporal variability in the model predictions (1–3 orders of magnitude) due to natural variability (e.g. hydrology, temperature), variations in emissions and uncertainty sources. Local mixture ecotoxicological pressures based on acute EC50 data as well as on chronic NOEC data, expressed as multi-substance potentially affected fraction of species (msPAF), were quantified in 114 separate locations in the waterbodies. It was estimated that 5% of the exposed aquatic species would experience exposure at or above their acute EC50 concentrations (so-called acute hazardous concentration for 5% of species, or aHC5) at only 7% of the locations analyzed (8 out of 114 l〈em〉o〈/em〉cations). For the evaluation based on chronic NOEC concentrations, the chronic HC5 (cHC5) is exceeded at 27% of the locations. The acute mixture toxic pressure was estimated to be predominantly caused by only three substances in all waterbodies: Furosemide, Tramadol and Ibuprofen. A similar evaluation of chronic toxic pressure evaluation logically demonstrates that more substances play a significant role in causing a higher chronic toxic pressure at more sites as compared to the acute toxic pressure evaluation. In addition to the three substances contributing most to acute effects, the chronic effects are predominantly caused by another five substances: paracetamol, diclofenac, ethinylestradiol, erythromycin and ciprofloxacin. This study provides regulatory authorities and companies responsible for water quality valuable information for targeting remediation measures and monitoring on a substance and location basis.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518324512-fx1.jpg" width="212" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 220〈/p〉 〈p〉Author(s): Qianqian Yu, Ling Feng, Xinna Chai, Xinhong Qiu, Hao Ouyang, Guanyu Deng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Although the heterogeneous Fenton process of iron-bearing minerals has been widely studied due to its potential use for the removal of organic pollutants, the transformation mediated by Fe species in soil particles remains poorly understood. Here, we compared the removal of bisphenol A (BPA) from soil using a Fenton system at low and high pH values. At low pH value, the BPA removal rate decreased with increasing pH value; this result was consistent with the amount of soluble Fe(II) and surface-bound Fe(II) observed in the soil systems. In contrast, an increased BPA degradation efficiency was observed at high pH, which is different from the traditional Fenton system. The electron spin resonance analysis verified that the high BPA degradation rate was attributed to enhanced ·OH generation. The binding environments of the Fe species in the soil for different reaction pH values were investigated by using Mössbauer spectroscopy combined with selective chemical extraction. A mixed-valence Fe(II) phase was observed at pH 12.0 and accounted for 12% of the total Fe content. The results indicate that in addition to the well-studied soluble Fe(II) and surface-bound Fe(II), structural Fe(II) located in the newly formed secondary precipitates may play a more important role in the generation of ·OH, especially at high pH values. These findings may provide insights into the utilization of Fe-bearing soil minerals as a renewable source for the degradation of organic pollutants over a wide pH range.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518324767-fx1.jpg" width="317" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 220〈/p〉 〈p〉Author(s): João Paulo Silva Pinheiro, Cecília Bertacini de Assis, Marcela Muñoz-Peñuela, Fernando Barbosa Júnior, Tiago Gabriel Correia, Renata Guimarães Moreira〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The toxicity of metals, including aluminum (Al), can be potentiated by temperature and acid pH, a concern in view of the current global warming scenario. The aim of this study was to evaluate the bioconcentration of Al in the testes and semen of 〈em〉Astyanax altiparanae〈/em〉 and the potential of this metal, at different environmental temperatures and acid pH, to cause cytotoxicity and genotocixity in erythrocytes and spermatozoa. 〈em〉A. altiparanae〈/em〉 males were divided into nine experimental groups: at each of three different water temperatures (20, 25 and 30 °C), the fish were exposed to a neutral pH, an acid pH and acidic water containing Al (0.5 mg.L〈sup〉−1〈/sup〉). The fish were subjected to subacute, semi-static exposure and sampled at 24 and 96 h. After each exposure period the comet assay (blood and semen) and micronucleus test (blood) were performed. Bioconcentration of Al was evaluated in the testes and semen. Exposure time and temperature influenced the Al bioconcentration pattern in the testes. Al concentration in the semen was higher in fish exposed at 20 and 25 °C (24 h). The DNA fragmentation score for the semen and blood was higher in fish exposed to Al at 20 (24 h) and 30 °C (96 h). The frequency of nuclear abnormalities in erythrocytes was higher in the group exposed to Al at 30 °C (96 h). It was concluded that Al bioconcentrates in the testes and semen of 〈em〉A. altiparanae〈/em〉 at different temperatures and is potentially cytotoxic and genotoxic to erythrocytes and spermatozoa in this species.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 220〈/p〉 〈p〉Author(s): Bingli Lei, Su Sun, Xiaolan Zhang, Chenglian Feng, Jie Xu, Yu Wen, Yangen Huang, Minghong Wu, Yingxin Yu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The negative health effects of bisphenol A (BPA) due to its estrogenic activity result in the increasing usage of alternative bisphenols (BPs) including bisphenol AF (BPAF). To comprehensive understand health effects of BPAF, the MCF-7 cells were used to investigate the effects of BPAF on cell proliferation, intracellular reactive oxygen species (ROS) formation, and calcium ion (Ca〈sup〉2+〈/sup〉) level. The molecular mechanisms of cell biological responses caused by BPAF were investigated by analyzing target protein expression. The results showed that low-concentration BPAF induces significant effects on MCF-7 cells, including promoting cell proliferation and elevating intracellular ROS and Ca〈sup〉2+〈/sup〉 levels. BPAF in low concentration significantly enhances the protein expression of estrogen receptor α (ERα), G protein-coupled receptor (GPER), 〈em〉c〈/em〉-Myc, and Cyclin D1, as well as increases phosphorylation levels of protein kinase B (Akt) and extracellular signal-regulated kinase (Erk) in MCF-7 cells. After the addition of ERα, GPER, and phosphatidylinositide 3-kinase (PI3K) inhibitors, phosphorylations of Erk and Akt were both inhibited. In addition, specific signal inhibitors significantly attenuated the effects of BPAF. Silencing of GPER also markedly decreased BPAF induced cell proliferation. The present results suggested that BPAF can activate PI3K/Akt and Erk signals via GPER, which, in turn, stimulate cellular biological effects induced by BPAF. ERα also plays a critical role in BPAF induced cellular biological effects.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518324573-fx1.jpg" width="414" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 220〈/p〉 〈p〉Author(s): Liwei Chai, Muke Huang, Hao Fan, Jie Wang, Dalin Jiang, Mengjun Zhang, Yi Huang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Soil organic matter (SOM) play an important role in soil ecology and global carbon dynamic. As one of the most sever and irreversible land use change, urbanization could alter the regional carbon storage and composition pattern. However how urbanization influence on SOM is still unclear. In this study, we collected soil samples from highly urbanized area of Beijing, China and explore the quantity and quality variations of SOM by using fluorescence spectroscopy in combine with parallel factor analysis (PARAFAC). The results shown that the soil physic-chemical properties were shaped by urbanization. Comparing to nature soil, moisture content, total organic carbon and total nitrogen in urban and rural soil significantly decreased. The fluorescence spectrum demonstrated that SOM quality was also altered by urbanization induced environmental changes. Five fluorescent compounds in SOM was identified by PARAFAC model and three of them was assigned to humic-like substances. The fluorescence intensity of humic-like substances in nature land was significantly higher than of rural and urban land, meanwhile microbial related substance accumulated in urban land in comparison with rural and nature land. The multivariate analyses further reveal the relationship between soil physic-chemical properties and SOM composition. These results suggest that urbanization could not only decrease the SOM quantity but also change the SOM composition. The SOM loss caused by urbanization was mainly consist of humic-like substance loss. Besides urbanization also stimulate the accumulation of microbial related substance in SOM which highlight the importance of microorganism is SOM dynamic.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 220〈/p〉 〈p〉Author(s): Yan Zhang, Xuelan Liu, Chunyan Fu, Xinhua Li, Baixing Yan, Tianhong Shi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Horizontal subsurface flow constructed wetlands (CWs) planted with 〈em〉Phragmites australis〈/em〉 were set up to analyze the effect of external ferrous iron (Fe〈sup〉2+〈/sup〉) addition on chemical oxygen demand (COD) and nitrogen removal. The results showed that external Fe〈sup〉2+〈/sup〉 addition has no significant effect on COD removal, while the COD removal efficiencies in CWs with Fe〈sup〉2+〈/sup〉 addition were slightly lower than those in CWs without Fe〈sup〉2+〈/sup〉 addition, since Fe〈sup〉2+〈/sup〉 as an electron donor for denitrification may decrease the consumption of organic carbon. However, external Fe〈sup〉2+〈/sup〉 addition significantly enhanced the nitrogen removal capability of the CWs. With an increase in external Fe〈sup〉2+〈/sup〉 concentration, the removal efficiencies for total nitrogen (TN), nitrate nitrogen (NO〈sub〉3〈/sub〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉N), and ammonium nitrogen (NH〈sub〉4〈/sub〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉N) all increased. The removal efficiencies for TN and NH〈sub〉4〈/sub〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉N were greatest for an influent Fe〈sup〉2+〈/sup〉 concentration of 50 mg L〈sup〉−1〈/sup〉, while the greatest removal efficiencies for NO〈sub〉3〈/sub〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉N were observed at an influent Fe〈sup〉2+〈/sup〉 concentration of 150 mg L〈sup〉−1〈/sup〉. With increasing hydraulic retention time (HRT), the COD and NO〈sub〉3〈/sub〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉N removal efficiencies in the CWs with external Fe〈sup〉2+〈/sup〉 addition increase sharply and then became stable, while the removal efficiency for TN exhibited a continuous increase. The removal efficiency for NH〈sub〉4〈/sub〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉N was greatest at an HRT of 5 d–7 d with Fe〈sup〉2+〈/sup〉 addition. The change in pH with increasing HRT indicated that external Fe〈sup〉2+〈/sup〉 addition did not significantly affect the pH value of the effluent water, but that the wetland systems caused an increase in effluent pH. Fe〈sup〉2+〈/sup〉 addition remarkably reduced the oxygen-reduction potential of both the influent and effluent water, which was beneficial to denitrification of microorganisms.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518324792-egi1043PWT1DGL.jpg" width="406" alt="Image 10431" title="Image 10431"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 220〈/p〉 〈p〉Author(s): Patrick C. D'Haese, Grant Douglas, Anja Verhulst, Ellen Neven, Geert J. Behets, Benjamin A. Vervaet, Karin Finsterle, Miquel Lürling, Bryan Spears〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The use of geo-engineering materials to manage phosphorus in lakes has increased in recent years with aluminium and lanthanum based materials being most commonly applied. Hence the potential impact of the use of these compounds on human health is receiving growing interest. This review seeks to understand, evaluate and compare potential unintended consequences on human health and ecotoxicological risks associated with the use of lanthanum- and aluminium-based materials to modify chemical and ecological conditions in water bodies. In addition to their therapeutic use for the reduction of intestinal phosphate absorption in patients with impaired renal function, the phosphate binding capacity of aluminium and lanthanum also led to the development of materials used for water treatment. Although lanthanum and aluminium share physicochemical similarities and have many common applications, their uptake and kinetics within the human body and living organisms importantly differ from each other which is reflected in a different toxicity profile. Whilst a causal role in the development of neurological pathologies, skeletal lesions, hematopoietic disorders and respiratory effects has unequivocally been demonstrated with increased exposure to aluminium, studies until now have failed to find such a clear association after exposure to lanthanum although caution is warranted. Our review indicates that lanthanum and aluminium have a distinctly different profile with respect to their potential effects on human health. Regular monitoring of both aluminium and lanthanum concentrations in lanthanum-/aluminium-treated water by the responsible authorities is recommended to avoid acute accidental or chronic low level accumulation.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 220〈/p〉 〈p〉Author(s): Jeremy Gingrich, Yong Pu, Richard Ehrhardt, Rajendiran Karthikraj, Kurunthachalam Kannan, Almudena Veiga-Lopez〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Bisphenol A (BPA), S (BPS), and F (BPF) are among the most abundant bisphenols detected in humans, yet pregnancy toxicokinetics for BPS or BPF remain unknown. Because gestational BPS can disrupt placental function and result in reproductive and metabolic disorders in the progeny, the aim of the study was to investigate BPS and BPF toxicokinetics during pregnancy using an 〈em〉in vivo〈/em〉 approach. Fetal catheterizations were conducted in pregnant sheep (n = 6) at mid-pregnancy and injected with either a single dose of BPS (n = 3, 0.5 mg/kg, s.c.), or a combination of BPS, BPF, and BPA (n = 3, 0.5 mg/kg for each chemical, s.c.). Maternal and fetal blood and urine and amniotic fluid were collected over 72 h and analyzed for bisphenols by HPLC-MS/MS. We observed significant differences in half-life, maximum concentration, and total body clearance in maternal circulation among bisphenols. Longer half-lives were observed in fetal 〈em〉vs〈/em〉. maternal circulation for all bisphenols. Fetal toxicokinetics differed among bisphenols with BPS having the longest fetal half-life. All bisphenols reached basal levels at 48 h in maternal plasma, but were still detectable in amniotic fluid, fetal urine, and fetal plasma at 72 h. In this first pregnancy toxicokinetic study of BPS and BPF we have demonstrated maternal and fetal toxicokinetic differences among all three bisphenols. Higher BPS persistence in the fetal compartment warrants studies into progeny adverse outcomes following gestational exposure. Additionally, toxicokinetic differences among bisphenols call for a more careful approach when extrapolating kinetic information from one bisphenol chemical to another.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 220〈/p〉 〈p〉Author(s): Tiziana Di Lorenzo, Andrea Castaño-Sánchez, Walter Darío Di Marzio, Patricia García-Doncel, Leonor Nozal Martínez, Diana Maria Paola Galassi, Sanda Iepure〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study we aimed at assessing: (i) the environmental risk posed by mixtures of caffeine and propranolol to the freshwater ecosystems of Spain; (ii) the sensitivity of freshwater copepod species to the two compounds; (iii) if the toxicity of caffeine and propranolol to freshwater copepods contributes to the environmental risk posed by the two compounds in the freshwater bodies of Spain. The environmental risk was computed as the ratio of MECs (i.e. the measured environmental concentrations) to PNECs (i.e. the respective predicted no-effect concentrations). The effects of caffeine and propranolol on the freshwater cyclopoid 〈em〉Diacyclops crassicaudis crassicaudis〈/em〉 were tested both individually and in binary mixtures. Propranolol posed an environmental risk in some but not in all the surface water ecosystems of Spain investigated in this study, while caffeine posed an environmental risk to all the investigated freshwater bodies, both as single compound and in the mixture with propranolol. Propranolol was the most toxic compound to 〈em〉D. crassicaudis crassicaudis〈/em〉, while caffeine was non-toxic to this species. The CA model predicted the toxicity of the propranolol and caffeine mixture for this species. 〈em〉D. crassicaudis crassicaudis〈/em〉 was much less sensitive than several other aquatic species to both compounds. The sensitivity of 〈em〉D. crassicaudis crassicaudis〈/em〉 does not increase the environmental risk posed by the two compounds in the freshwater bodies of Spain, however, further testing is recommended since the effect of toxicants on freshwater copepods can be more pronounced under multiple stressors and temperature increasing due to climate change.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemosphere, Volume 220〈/p〉 〈p〉Author(s): Peng Zeng, Zhaohui Guo, Xiyuan Xiao, Chi Peng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Tree-herb co-planting is regarded as an ecologically sustainable approach for the remediation of metal(loid)-contaminated soil. In this study, two herb species, 〈em〉Pteris vittata〈/em〉 L. and 〈em〉Arundo donax〈/em〉 L., and two woody species, 〈em〉Morus alba〈/em〉 L. and 〈em〉Broussonetia papyrifera〈/em〉 L., were selected for the tree-herb co-planting, and their impacts on the changing of microbial community structure in metal(loid)-contaminated soil were studied by high-throughput sequencing. The results showed that the microbial diversity was stably maintained by the tree-herb interactions, while the composition of the microbial community was clearly affected in metal(loid)-contaminated soil. According to the Venn and flower diagrams, heat map and principal coordinate analysis, both plant monocultures and co-planting had specific microbial community structures, which suggested that the composition and abundance of bacterial communities varied between plant monoculture and tree-herb co-planting treatments. In particular, 〈em〉A. donax〈/em〉 L. played a vital role in increasing the abundances of 〈em〉Cyanobacteria〈/em〉 (〉1%) in metal(loid)-contaminated soil when co-planted with woody plants. Furthermore, some specific microorganisms combined with plants played a key role in improving enzyme activity in the contaminated soil. Correspondingly, sucrase and acid phosphatase activities in monoculture and co-planting treatments significantly (〈em〉p〈/em〉 〈 0.05) increased by 1.05–3.37 and 7.24–20.3 times. These results indicated that the rhizospheric interactions in the tree-herb co-planting system positively affected the soil microbes and had stronger impacts on the composition of soil microorganisms, which was closely related to the improvement of the biological quality in the metal(loid)-contaminated soil.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0045653518323956-fx1.jpg" width="396" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉