ALBERT

Description: Publication date: Available online 23 June 2018 Source: Sustainable Environment Research Author(s): Rey P. Gumaling, Jay R.E. Agusan, Neil Ven Cent R. Ellacer, Gretel Mary T. Abi Abi, Jasmin Roxatte P. Pajaron, Jose Rey Q. Joyno, Cherry Q. Joyno, Alexander L. Ido, Renato O. Arazo Low recovery coupled with intensive energy requirement due to long processing time makes the potential of bio-oil production not seamlessly appreciated. In this study, the optimization of bio-oil yield from non-edible Swietenia macrophylla seeds through microwave pretreatment before ultrasonic-assisted solvent extraction was investigated. Central composite design of response surface methodology was employed to analyze the effects to the bio-oil yield of the irradiation time (4-8 min) and irradiation power (90-450 W) as pretreatment variables using a microwave oven at 2.45 GHz frequency. Results showed that microwave pretreatment significantly increased the bio-oil yield by 5% with optimum recovery of 43% at shortened pretreatment time of 7 min instead of 6 h in the conventional oven heating method. The bio-oil yield increased when the irradiation time was increased, while irradiation power showed no significant effect. Analysis of the produced bio-oil through Fourier Transform Infrared Radiation spectroscopy identified similar functional groups present both in the extracted bio-oils from the microwave and the conventional pretreated seeds indicating that the former pretreatment, like the latter, did not destruct the compounds present in the seeds. The study demonstrated that the seeds of S. macrophylla have strong potential for bio-oil production and poise huge implications to the future of liquid biofuel and chemical industries.

Description: Publication date: Available online 19 June 2018 Source: Sustainable Environment Research Author(s): Clark C.K. Liu Ocean thermal energy conversion (OTEC) is an energy generation technology that uses cold deep ocean water (DOW) and warm surface water to produce electricity. Active development of OTEC was started in the 1970s with Hawaii as a major research and development center. In the following several decades, small pilot-scale closed-cycle and open-cycle OTEC plants were successfully designed, constructed, and tested. An open-cycle OTEC plant produces both electricity and freshwater. Besides its low temperature, DOW is also nutrient-rich and free from pathogenic bacteria. DOW-enhanced open ocean mariculture can significantly increase the world fish catch and induce an air to water transfer of greenhouse gas CO 2 . Therefore, an integrated development of DOW as a natural resource is the center of a “blue revolution” that has the potential to solve four of the most urgent world problems: energy, freshwater, food, and global warming. This paper will review technological development of OTEC and open ocean mariculture, followed by a discussion of the prospect of Mainland-Taiwan research collaboration on the technological development and application of DOW resources.

Description: Publication date: Available online 19 June 2018 Source: Sustainable Environment Research Author(s): Tran Ngoc Phu Nguyen, Quynh Thi Phuong Bui, Chihpin Huang In recent years a number of studies on the optimization of operating parameters on hydrogen-based denitrifying system with several investigations on autohydrogenotrophic bacterial community carried out. However, it appears that long-term performance of a hydrogen-based denitrifying system and the characterization of microbial community under various hydrogen flow rates have not adequately been focused on yet. This study is thus aimed at evaluating denitrification efficiency of a continuous-flow autohydrogenotrophic bioreactor, and characterizing changes in influential parameters, sludge characteristics and microbial community under long-term operation at various hydrogen flow rates. A hydrogen-fed bioreactor was operated at hydrogen supply rates of 50, 90 and 30 mL min -1 for 3 months. Stable and complete autohydrogenotrophic denitrification with the nitrogen loading rate in the range of 0.33-0.38 kg N m -3 d -1 was obtained when the hydrogen supply rate was at 90 mL min -1 , while nitrite accumulation and strong fluctuations in total nitrogen removal efficiencies were observed at lower hydrogen levels. Changes in sludge characteristics, including the production of soluble and bound extracellular polymeric substances and microbial floc size distribution, were monitored. The diversity of the autohydrogenotrophic microbial community and changes at class and phyla levels at varying hydrogen supply rates were analyzed by means of high-throughput sequencing technology. As many as 200 observed operational taxonomic units were identified in the autohydrogenotrophic sludge. The phyla Proteobacteria, Chlorobi and Bacteroidetes were found to account for more than 95% of the denitrifying microbial community, and the classes Alphaproteobacteria, Betaproteobacteria and Deltaproteobacteria appeared as the most abundant taxa in the bioreactor.

Description: Publication date: Available online 23 May 2018 Source: Sustainable Environment Research Author(s): Salah Zereg, Abderrahmane Boudoukha, Lahcen Benaabidate The “Merdja” is the shallow aquifer of Tebessa plain, located in the northeast of Algeria. The climate is typical of semi-arid steppes, where extensive agro-pastoral activities are dominating. It is still the main water resource used by major sectors. Due to its proximity to the City, it is vulnerable to pollution. According to earlier studies, this aquifer undergoes seasonal water quality fluctuations (between wet and dry seasons), induced mainly through anthropogenic activities. The study is utmost important, as it tracks the groundwater quality and aims to gain an understanding of how the local and natural conditions influence this resource at temporal (interannual) and spatial scales, by following up the evolution trend of hydrochemical parameters of the “Merdja” aquifer. Seventy-one groundwater samples were collected and analyzed from drinking/irrigation wells, through four field measurement campaigns (2001, 2006, 2009, and 2010). The results obtained confirm the fact of water pollution. Point-sources of pollution with nitrate and salinity are revealed on the respective maps of these parameters, especially downstream at the nearby areas of Tebessa City. Non-point sources of groundwater pollution are also manifested. The Piper diagram reveals a relative stability of water type and that rainfall plays a role in the natural remediation, by taking part in the aquifer recharge. The ionic ratios and the principal components analysis highlight that the temporal change of groundwater quality results respectively from: (i) ionic exchange process and the dissolution of evaporites; (ii) the sources of nitrate in groundwater remain the excess application of inorganic nitrogenous fertilizers, organic manures, and wastewater effluents.

Description: Publication date: Available online 23 May 2018 Source: Sustainable Environment Research Author(s): Anijiofor Sandra Chinenyenwa, Nik Daud Nik Norsyahariati, Idrus Syazwani, Che Man Hasfalina The waste to wealth initiative has been championed by many researchers through the use of waste materials as adsorbents for wastewater treatment. The aged refuse became a research interest due to its availability, low cost and adsorption capacity. The aged refuse used was collected from the Air Hitam Sanitary Landfill site in Selangor, Malaysia which is more than 8 years of placement. The material characterization showed characteristics such as high porosity (51%), bulk density ( ρ ), 1.23 g cm -3 , total surface area (Brunauer-Emmett-Teller) of 3.376 m 2 g -I , capacity for exchange of cations and organic content of 9.90% which are ideal conditions for adsorption. The optimized operating conditions during treatment were dosage of 2 g 100 mL -1 , pH 6, particle size ≤ 2 mm, agitation speed 250 rpm, and contact time of 70 min. The results showed maximum reduction efficiency of 91% for Chemical oxygen demand, Total suspends solids and Total dissolved solids and 84, 88 and 95% for Biochemical oxygen demand, NH 4 + and Colour respectively and over 60% removal was observed in 10 min. Freundlich model was used to test the experimental data and it gave good correlation with R 2 values very close to 1. The aged refuse technology is suitable for wastewater recovery and reuse through innovative column based aged refuse biofilter which incorporates adsorption, filtration, biodegradation and sedimentation processes.

Description: Publication date: Available online 22 May 2018 Source: Sustainable Environment Research Author(s): Jules Chuang, Hsing-Lung Lien, Walter Den, Luvian Iskandar, Pei-Hsuan Liao Energy generation contributes nearly 40% of global greenhouse gas (GHG) emissions, and half of energy generated is purchased and used by industrial or commercial entities (Scope 2 category emission). Other than conserving energy and upgrading energy efficiency to reduce GHG emissions, these Scope 2 entities can switch to low-carbon electricity generated by renewable sources, whether through on-site installations or through energy products purchased. An electricity tracking and certification framework, such as the renewable energy certificate (REC), can be a powerful policy instrument to promote the acquisition of low-carbon electricity by the Scope 2 users. Designing, implementing, and regulating a REC framework must be meticulous in the determination of the electricity emission factor (in CO 2 equivalent per unit power generated). This article uses several simplified scenarios to illustrate the advantage of implementing a trackable REC system to avoid the “free-rider effect” in the electricity market, and the proper accounting mechanism for the inclusion of onsite installations of renewable energy to eliminate the “outsider effect”. Still in its early phase of implementing a REC instrument to reach the GHG emission reduction goal, Taiwan has a chance for successful transition from the existing fossil fuel-rich energy portfolio to a low-carbon one, through reforming its energy infrastructure and introducing incentive-driven policies. Therefore, this paper also provides constructive recommendations to the policy-makers on the deployment of the REC system.

Description: Publication date: Available online 9 May 2018 Source: Sustainable Environment Research Author(s): Biswaranjan Dhal, Abhilash, BanshiDhar Pandey Mechanism of Cr(VI) bio-removal from mine drainage was studied using a native fungal isolate. The Cr(VI) tolerant species, from Chromite mining at Sukinda mine water fungus characterized as Aspergillus fumigatus Fresenius was applied after in activation in an autoclave, to optimize the parameters of biosorption. Maximum uptake of 48.2 mg Cr(VI) g -1 of inactivated biomass at pH 5.5, 35 °C and 1% sorbent/solution (w/v) ratio was obtained (>96% sorption) in 120 h from 50 mg L -1 Cr(VI) solution. The chemisorption mechanism involved the functional groups of treated biomass was elucidated by the Fourier-transform infrared spectroscopy, X-ray powder diffraction (XRD) and Scanning Electron Microscopy with Energy Dispersive Spectroscopy studies. The XRD phase analysis of the biosorbed material confirmed the limited reduction of Cr(VI) to Cr(III) unlike previous studies. Actual mine drainage containing Cr(VI) and Co(II) was treated with the fungal biomass and was effectively eluted with 0.5 M HCl solution. The study demonstrates the potential application of native fungal isolate to remediate Cr(VI) from the chromite mine drainage.

Description: Publication date: Available online 9 May 2018 Source: Sustainable Environment Research Author(s): Saaida Lhanafi, Zakaria Anfar, Bouchra Chebli, Mohamed Benafqir, Rachid El Haouti, Youness Azougarh, Mohamed Abbaz, Noureddine El Alem Factorial design was used to investigate the parameters involved in co-digestion mixture of dairy wastes (from a Moroccan dairy industry) in order to improve methane production of this mixture. Indeed, evaluation of methane yield as a function of three parameters (pH, inoculum and organic load) showed the correlation between the experimental and statistical data in terms of pH 8 and inoculum 1 (constituted by sludge diluted in 1 L of basal medium of methanogenic bacteria, in addition to formic acid (5 mL L -1 ), propionic acid (5 mL L -1 ), lactic acid (5 mL L -1 ) and micro-nutrient (10 mL L -1 )) as optimum parameters. However, a discrepancy was detected about organic load. The interaction between parameters had a positive effect on methane yield because it led to produce experimentally a maximum methane using the higher load (3.44 g VS). These results allow selecting the parameters for the improvement of methane production. Furthermore, the validity of the fitting model to describe and improve the efficiency of dairy wastes co-digestion was investigated. In addition, an abatement of 89% of volatile solids was observed and the mineral solids was increased from 4 to 7.2 g L -1 , which is important of digestat value as fertilizer.

Description: Publication date: Available online 30 April 2018 Source: Sustainable Environment Research Author(s): Touhid Bin Anwar, Bushra Behrose, Shoeb Ahmed Textile wastewater is one of the major water pollution concerns in the manufacturing countries. However, the sludge from these wastewater treatment plants is often discarded to the environment and therefore is exposed to flood with rain causing the soil and water contamination. Therefore, there is a growing need to look for various applications of sludge handling for sustainable development. Typical textile sludge was found to have very high (∼80%) moisture content, however the dry sludge had a decent heating value (>17 MJ kg -1 ). Different textile sludge/clay mixtures (0.5 to 5.25% dry sludge) were used to make bricks, which were evaluated in terms of their compressive strengths and the leaching behavior. The textile sludge incorporated clay fired bricks showed up to 77% more compressive strength compared to average standard bricks. The leaching test of clay-fired cubes exhibited very low water absorption (0.8-1.3%), which is desirable for various applications. From the cytotoxicity assessment of textile industrial sludge, lethal Concentration 50% was found to be at 262 μM concentration of sludge solution, based on Cr level. This value is significantly higher than the leachate concentration and thus indicates the potential of sludge as a building material without the possibility of heavy metal contamination to surroundings.

Description: Publication date: Available online 21 April 2018 Source: Sustainable Environment Research Author(s): Khyle Glainmer Quiton, Bonifacio Doma, Cybelle M. Futalan, Meng-Wei Wan In this study, the capacity of E. coli and Staphylococcus epidermidis biofilms supported on kaolin in the removal of Cr(VI) and Zn(II) from aqueous solution was investigated in batch assays. The effect of initial metal concentration and contact time on the removal efficiency of Cr(VI) and Zn(II) using E. coli and S. epidermidis biofilms supported on kaolin. Isotherm studies show that the Freundlich isotherm best describes the Zn(II) biosorption by E. coli and S. epidermidis biofilms and Cr(VI) biosorption onto S. epidermidis biofilm, and Langmuir isotherm for Cr(VI) biosorption by E. coli biofilm supported on kaolin. The kinetics of Cr(VI) and Zn(II) best fits the pseudo-second order kinetic model (R 2 > 0.98), which implies that chemisorption is the rate-limiting step. The adsorptive capacity of Gram-negative E. coli is higher than the Gram-positive S. epidermidis in the removal of Cr(VI) and Zn(II) from aqueous solution.