ALBERT

Beschreibung: A novel integrated process to coproduce bioethanol and lignosulfonate from bamboo residues was investigated. Explicitly, the fermentable sugars (glucose and xylose) were saccharified from the kraft pulped bamboo residues with 12 % effective alkaline charge, followed by a sequential fermentation strategy was applied to produce bio-ethanol from these fermentable sugars. The kraft lignin (KL) generated in pulping process and the enzymatic hydrolysis residues (EHR) were sulfomethylated to produce lignosulfonate. Results showed that 229.8 g of KL, 495.6 g of fermentable sugars (368.7 g glucose and 126.9 g xylose) and 103.6 g of EHR were generated from 1000 g bamboo residues after consequent processes of kraft pulping and enzymatic hydrolysis, respectively. Under optimal conditions of fermentation and sulfomethylation, 1000 g bamboo residues could produce 201.4 g of ethanol (158.7 g from glucose and 42.7 g from xylose) and 234.9 g of pure lignosulfonate (197.6 g from KL and 37.3 g from EHR) from 1000 g bamboo residues. This integrated process may potential be an economically profitable for the biorefinery of bamboo residues.

Beschreibung: Purpose An improvement of the methodology used for the implementation of the first industrial symbiosis platform in Italy is proposed aimed at solving some critical issues encountered during its application at a regional scale in Sicily. Methods The investigation mainly focused on the phases of companies’ involvement and operative meeting organization. The different sectors characterizing the companies participating in the meetings were analyzed and compared with the productive system features in the investigated area. Resources shared by the companies during the operative meeting and the individuated potential matches were analyzed, as well. Results Several critical issues were identified: (a) the low grade of diversification of participating companies that was not fully representative of the actual productive system so limiting the information on the potential matches; (b) the disequilibrium between observed supply and demand due to the prevalent interest of participating companies in finding out alternative solutions for the disposal of their residues rather than to find alternative supplies for their processes; (c) the excessive offers of services and expertise; (d) companies concern about a potential increase in controls on their activities. Conclusions S olutions were proposed to increase the “biodiversity” of the firms, the level of companies knowledge on the potential for substituting their input resources, the control of “alien” species and to promote greater confidence in the symbiosis approach between the companies, as well as a greater awareness between the same stockholders. Finally the encouragement of paths that are not so financially attractive but that can have a strong positive impact on the environment is proposed.

Beschreibung: Capia pepperseed meals obtained from cold pressing by applying pretreatments such as roasting and enzyme treatment were used for protein extraction. The optimum extraction conditions were pH 9.0 and 0.2 or 0.6 M NaCI solution with pH 4.0 and 4.5 for isoelectric point precipitation. Under these conditions, the protein yields were 40, 33 and 15 % for control, roasted and enzyme treated samples, respectively. The functional properties like water and oil holding capacities (WHC and OHC), emulsifying activity (EA) and emulsion stability (ES) values, foaming capacity (FC) and foam stability (FS) values indicated that these proteins can be utilized in food products. Furthermore, the thermal properties and amino acid composition of the samples were measured. Gel electrophoresis showed 5 bands, and some were absent in the enzyme treated samples, indicating some protein loss by the enzyme treatment. In conclusion, capia pepperseed proteins are nutritionally balanced, and a limited pre-roasting would be beneficial for enhanced functional properties. Hence, protein extracts from the cold pressed pepperseed meals could be used for human food product applications.

Beschreibung: Purpose The objective of the present study was to valorize the tiger tooth croaker ( Otolithes ruber ) fish head waste for the extraction of high value protein based component ‘gelatin’. Methods Gel strength, gelling and melting point and setting time, viscosity, turbidity, colour, emulsion activity and stability index and SDS–PAGE technique. Results The gel strength of extracted croaker fish head waste gelatin was 45 g and had lower gelling (11 °C) and melting temperature (20.25 °C) and took more time (366 s) to gel at 11 °C compared to standard porcine gelatin of low bloom category. Colour analysis revealed that the whiteness and redness intensity of fish head waste gelatin were lower than the porcine gelatin. However, there was no significant difference in yellowness value between fish head waste gelatin prepared and porcine gelatin. The emulsion activity index of fish head waste gelatin decreased with increase in protein concentration. The SDS–PAGE analysis showed the presence of α-component and multiple low molecular weight peptides up to 45 kDa. Conclusion Croaker fish head waste could be utilized for extraction of gelatin of low bloom category. Appropriate changes could be incorporated in the process to obtain gelatin with higher gel strength.

Beschreibung: Activated carbons were prepared from wheat straw, a wide spread biomass waste in North China, via ZnCl 2 and KOH activation. The characteristics of ZnCl 2 and KOH activated carbon were compared using N 2 -adsorption, scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. The adsorption behaviors of the activated carbons for the removal of methylene blue (MB) from aqueous solution were investigated, and the MB-saturated activated carbon was regenerated by thermal treatment. The experimental data demonstrated that ZnCl 2 activated carbon had a higher surface area and more micropores. Also, the ZnCl 2 activated carbon had a more developed aromatic structure. The differences in the characteristics were attributed to the different activation mechanisms of ZnCl 2 and KOH. The adsorption equilibrium data of ZnCl 2 and KOH activated carbon followed Langmuir isotherm model with the monolayer adsorption capacities of 265.96 and 146.84 mg/g, respectively. Pseudo-second-order kinetic model better described the adsorption kinetic of ZnCl 2 activated carbon, and the diffusion mechanism was well described by Weber and Morris intraparticle diffusion model. The MB-saturated ZnCl 2 activated carbon can be effectively regenerated by thermal treatment, and the regeneration efficiency was higher than 70 % after five regeneration cycles.

Beschreibung: Lignin, the second most abundant natural polymer, has emerged as a potential alternative material to petroleum-based chemicals and renewable resource for the production of diverse forms of aromatics, biofuels, and bio-based materials. Thus, it is becoming important to understand its structure and properties to provide key features and insights for better/efficient lignin valorisation. In this work, the physicochemical characterisation of two types of industrial (technical) lignins, namely LignoBoost lignin and alkali-treated lignin was performed. Characterisation has been conducted using Brunauer–Emmett–Teller N 2 adsorption, particle size distribution, Fourier transform infrared spectroscopy, ultraviolet–visible absorption spectroscopy, gel permeation chromatography, and thermogravimetric analysis. It was found that the pretreatment severity considerably influenced the lignin composition and functional properties. The measured physicochemical properties helped in proposing potential valorisation routes for these lignins in the context of a biorefinery, focusing on their depolymerisation and subsequent biological conversion to value-added chemicals and fuels.

Beschreibung: Nutrient recovery from digested biodegradable waste as marketable products has become an important task for anaerobic digestion plants to meet both regulatory drivers and market demands, while producing an internal revenue source. As such, the present waste problem could be turned into an economic opportunity. The aim of this study was to provide a comprehensive overview and critical comparison of the available/emerging technologies for nutrient recovery from digestate, and a classification of the resulting end-products according to their fertilizer characteristics. Based on the stage of implementation, the technical performance, as well as financial aspects, struvite precipitation/crystallization, ammonia stripping and (subsequent) absorption using an acidic air scrubber were selected as best available technologies to be applied at full-scale for nutrient recovery as marketable fertilizer commodities. The resulting end-products can and should be classified as renewable nitrogen–phosphorus (N/P) precipitates and nitrogen–sulfur (N/S) solutions, respectively, in fertilizer and environmental legislations. This would stimulate their use and foster nutrient recovery technology implementation.

Beschreibung: Within Europe, more than 300 islands are inhabited by more than 3 % of the total EU population, i.e. 15 million residents live in areas experiencing permanent disadvantages and vulnerabilities, such as shortage of natural resources, economic and demographic stresses that pose additional pressure to environmental problems. Given that, waste management is considered one of the biggest challenges. This paper presents a comprehensive methodology on the development, implementation and evaluation of an integrated municipal solid waste management scheme in line with the Waste Framework Directive 2008/98/EC in selected communities of Tinos island (Greece). For the first time, in Greek insular communities, a holistic separate collection of dry recyclables and biowaste was implemented in order to facilitate recycling and further valorization of high-purity materials. The applied integrated solid waste management scheme proved to be efficient and effective as it led to satisfactory source separation rates of packaging waste, reaching 86.5 % of total packaging waste generated (including mixed paper). Moreover, approximately 15.5 kg cap −1  year −1 biowaste was captured and along with other local practices (e.g. use as animal feed), the total diversion rate from landfill reached 37.0 % of biowaste produced. Overall, the pilot scheme (including local practices) diverted from landfilling 34.2 % of the total Municipal Solid Waste generated, accounting for 148.2 kg cap −1  year −1 . These results provided guidance to develop an up-scaled sustainable, cost-efficient and flexible waste management plan, using alternative scenarios, to cover the needs of the whole island.

Beschreibung: This work examined the social perception of the population towards the management of livestock waste (LWM) in Cyprus. A questionnaire was designed based on major concerns of citizen extracted from literature reviews. These concerns were integrated into questions related to impact aspect of LWM, people perception on the subject, and to the management aspect. The questionnaire was sent to more than 100 individuals residing close to LWM facilities. A relation between risk perception and level of information was found. On a scale 1–5, the responses showed that the greatest problems as perceived by the population are odour issues (3.9), health issues and the adverse impact on property values (both 3.2). Although 81 % of the respondents stated that they have some information or are well informed about LWM in their area, they often tend to evaluate improperly functionality of the facility. Odour emissions are seen as an indication of improper operation of the facility; respondents usually agree on the fact that the current livestock waste treatment system is not adequate compared to the requirements. Finally, the participants in the survey believe that LWM activities cannot significantly improve the employment level in Cyprus. The job estimate for biogas power plant is 0.62 job-years/GWh, which is higher compared to other type of renewable energy installations.

Beschreibung: This paper has been aimed for thermochemical gasification of Pongamia residue (mixture of shells and de-oiled cake) generated from the oil expellers and biodiesel production plants. Pongamia mixture pellets (with 11.5 mm diameter and average length in the range of 10–62 mm) were prepared and gasify in an open top downdraft wood gasifier. The temperature in various zones of the gasifier was measured by using S-type thermocouples. The calorific value of producer gas generated from pellets was in the range of 4.56–5.39 MJ/Nm 3 . The gasifier conversion efficiency was 94 % for pellets which is higher to that of wood gasification (74 %). Producer gas generated with these pellets was used in the spark ignition engine. The performance and emission characteristics of the engine were evaluated by varying load and spark timings. The engine brake thermal efficiency was 26 % at spark ignition timing 30° before top dead centre (bTDC) at full load condition. However, the de-rating of 4.5 % was observed when working with 100 % producer gas at compression ratio of 10. Emission parameters were on lower side at spark timing 30 o bTDC. The producer gas generated from the Pongamia mixture pellets could be used for heat and or power generation for rural areas.

Beschreibung: The desire to protect the environment for future generations has led to the reutilization of all recoverable and recyclable wastes. Consequently, different residues from various sources were collected to make mixed compounds to be used as catalyst supports. Such wastes included sand and cement from the building industry, nonreturnable glass bottles, and used tires. The synthesized supports were impregnated with molybdophosphoric acid, a heteropolyacid with Keggin structure, and characterized by potentiometric titration, optical microscopy, SEM–EDS, and textural property analyses. The bifunctional properties of the new catalysts were evaluated in two relevant transformations in green conditions: (i) the selective oxidation of sulfides to sulfoxides using a green oxidant such as tert -butyl hydroperoxide, and (ii) the multicomponent synthesis of 3,4-dihydropyrimidinones (Biginelli reaction, catalyzed in acid media). Graphical Abstract

Beschreibung: The current increase in the bulge amount of marine fish wastes produced by the marine industries has led to search for new efficient and judicious disposal methods. Hence the present study was undertaken on production and purification of halophilic organic solvent tolerant protease (HOSP) from marine Bacillus sp. APCMST-CS4 using marine shell wastes as substrate. Statistical media obtained optimization inferred that, anchovy powder (20.00 g/L), crab shell powder (12.5 g/L), NaCl (100.00 g/L), and CaCl 2 (3.00 g/L) favored maximum protease activity (1,398.20 U/mL) and it was found to be an alkaline HOSP. This HOSP was purified to 8.10 fold with 29.52 U/mg specific activity and its molecular weight was 21 kDa. Further this HOSP was tolerant to temperature (60 °C), pH (8), NaCl (2.5 M), metals, surfactants, solvents and commercial detergents and exhibited maximum activity. The serine and metalloprotease inhibitors were highly inhibited the activity of HOSP; hence this protease was referred as serine metalloprotease. The candidate strain had the ability to deproteinize (80.17 %) the crab shell waste and also displayed maximum antioxidant activity. FTIR and 13 C CP/MAS NMR study revealed the presence of pure ∝-chitin in the HOSP fermented crab shell waste and it emerged as a potential alternate method for the production of chitin. Graphical Abstract

Beschreibung: The aim of this article is to present the research carried out over a 10 year period to develop an environmentally safe method for recycling air pollution control (APC) residues. The initial studies aimed to formulate a mixture of weathered bottom ash (WBA), APC residues and Portland cement (PC) to be used as a sub-base in road constructions. Mechanical performance was subsequently enhanced by preparing a mortar prior to mixing it with WBA in order to obtain a granular material. After testing different formulations, the optimum mortar consisted of 50 % APC residues and 50 % PC. The evaluation was carried out based on the concentration release of the heavy metals and metalloids included in the Catalan legislation for revalorization of residues. After the applicability of the granular material was successfully demonstrated at laboratory scale from an environmental and mechanical point of view, a pilot scale plant was designed in order to assess its performance in a real scenario during 4 month. Thus, three roads were built: two containing 100 % granular material and a third containing 100 % WBA. The results showed that the immobilisation of all toxic species from APC residues is accomplished by the pozzolanic effect of the cement. The WBA, APC, and PC proportions show to be the most appropriate for compliance with regard to environmental and mechanics requirements.

Beschreibung: Flue gas desulfurization (FGD) gypsum and textile fibers constitute two large-scale industrial wastes generated in China. In this work, these wastes were used for making foamed concrete which can increase the energy efficiency of buildings. The effects of the W/S ratio, super plasticizer amount, foaming agent as well as textile fibers contents on the compressive strength and density values of the porous FGD gypsum plaster materials was systematically investigated. The highest compressive strength value of the gypsum blocks was 1.6 MPa after 7 days of curing, and the measured density value was 617 kg/m 3 . The obtained results suggest an effective way to recycle FGD gypsum and textile fiber wastes in order to produce not only low-cost and effective buildings materials, but also to lessen the environmental impact.

Beschreibung: In this study, a series of ionic liquids including conventional, protic and Brønsted acidic-type ionic liquids were evaluated as media for the pretreatment of Taiwan grass. The pretreatments were carried out in parallel format, for the first time, in a novel glass reactor known as Q-tube ® . Based on the results, the Q-tube ® was very efficient for the pretreatment of our lignocellulosic materials in comparison with the conventional equipment (round bottom flask). Pretreatments were completed in one hour with high yield of reducing and total sugars after enzymatic hydrolysis. Some protic and Brønsted acidic ionic liquids can depolymerize partially the cellulosic material in one step and after enzymatic hydrolysis the content of reducing sugars is up to 35 times higher in comparison with the material without pretreatment.

Beschreibung: This study was performed to produce lipids from the isolated oleaginous yeast Rhodotorula glutinis SO28 using loquat kernel extract (LKE) as substrate. LKE was prepared using acid hydrolysis and alkaline neutralization steps. Lipid production was performed in shaking flaks culture. Even if LKE was used as a sole source of nutritional substances, it could support cell growth and lipid synthesis in the yeast. Additional carbon, nitrogen and phosphorus sources were found to significantly alter the lipid accumulation potential of the yeast. Optimal concentrations of additional carbon (glucose) and nitrogen (ammonium sulphate) sources for lipid accumulation were determined as 15 and 0.5 g/L, respectively. On the other hand, all the concentrations of additional phosphorus source were found to significantly reduce the lipid accumulation. Optimal incubation time was determined as 132 h. Under the optimized culture conditions, the lipid concentration and lipid content of the yeast were determined as 7.82 g/L and 62 %, respectively. Fatty acid methyl ester analysis exhibited that this yeast strain could produce high proportions of C16:0 and C18 fatty acids, which are ideal for biodiesel production. This is the first report on the use of waste loquat kernels as substrate for microbial lipid production.

Beschreibung: Ciudad Madera is a town in the mountains of the northwestern Mexico in which the activity of lumber mills generates large amounts of waste in the form of sawdust, wood chips, and shavings. Pellet production from these residues could be implemented as an environmental solution which could also generate an economical benefit for the region and, consequently, for the country. In this study, we examined the feasibility of pelletizing forest residues by first determining the chemical and energy characteristics of the residues and then by analyzing the cost of production of pellets. According to the results, residues reached a higher heating value of 22.13 MJ/kg and the chemical characteristics of the pellets meet the requirements of the DIN Plus standard for high-quality pellets. An analysis of sensitivity indicates that if the owners of the mills (also owners of forest residues) install its own factory pelletizer, the cost of the raw material could be removed; this results in an 80 % decrease in the total cost of pellet production. Our results also indicate that pellets can be produced at a rate of 3 ton/h whit a specific cost of US$152/ton of pellets (when the cost of the raw material (sawdust) is taken into account) or with a cost of US$23/ton of pellets, (when the owners of the raw material installed their own factory pelletizer). The results of this study suggest that, as long as the price of raw materials is controlled, pelletizing forest residues is an economically attractive opportunity for conifer areas in México.

Beschreibung: The chemical composition of biochars varies considerably depending on the chemical composition of biomass used for its production and conditions of the thermal conversion process. In the context of chemical composition, biochars are different from other types of organic matter in that they contain many more aromatic carbon compounds. The aims of this study were as follows: (1) to investigate the effect of pyrolysis process of plant material on the concentrations of macroelements, trace elements and polycyclic aromatic hydrocarbons (PAHs) in the biochars; (2) to evaluate the ecotoxicity of the biochars; (3) to integrate chemical and toxicity properties of biochars in order to assess their safe utilisation as fertiliser materials. It was found that the elemental composition, the contents of macronutrients and trace elements in biochars were determined by the type of converted biomass. In the case of contents of volatile elements, such as nitrogen and sulphur, the process conditions were of great importance. Among the analysed trace elements, only the cadmium content exceeded the limit value for premium class biochars. The process of thermal conversion of organic materials did not cause mobilisation of available forms of most of the studied trace elements. In the course of the study, it was found that the extracts from wheat straw biochar (WSB) were low-toxic, while the extracts from biochars derived from rape straw (RSB), Miscanthus straw (MSB), sawdust (SB), bark (BB) and leaves of trees (LTB) were highly toxic to V. fischeri. Based on the response of the test organism, the analysed biochars were arranged in the following order: WSB 〈 BB 〈 RSB 〈 LTB 〈 MSB 〈 SB. The highest total content of PAHs (∑ 16 PAHs) was determined in rape straw biochar, and the lowest, in sawdust biochar. The studies revealed a negative correlation between the content of most of PAHs and inhibition of Vibrio fischeri luminescence. Graphical Abstract

Beschreibung: Coal tar pitch (CTP) was modified with paraformaldehyde (POM) within the presence of p -toluene sulfonic acid (PTS). CTP and the modified CTP (MCTP) were characterized by elemental analysis, X-ray diffractometer, scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). The pyrolysis behaviors of CTP and MCTP were studied by thermogravimetric analysis (TGA), and the pyrolysis kinetics were analyzed via Coats-Redfern method which based on the TGA data. Experimental results demonstrated that MCTP had a higher polymerization degree, leading to an increase in carbonization yield by 14 wt%. The anisotropic degree of CTP was increased after modification by POM. New phases were formed during modification, and their decomposition was to be suppressed when pyrolyzed, while they underwent more polymerisation reactions at higher temperatures. CTP had a single pyrolysis stage, which can be described by the second order reaction model (F2). And the activation energy of CTP pyrolysis was 38.32 kJ mol −1 . The pyrolysis of MCTP contained three stages, which the third order reaction model (F 3 ), the fourth order reaction model (F 4 ) and the one-dimensional diffusion (D 1 ) model were the most probable mechanisms for the three stages, respectively. The activation energies of the three stages were 56.20, 86.89 and 9.10 kJ mol −1 , respectively.

Beschreibung: Spent coffee grounds (SCG) is an agro-industrial waste which could potentially be tapped as feedstock for biofuel production. The direct hydrolysis of non-delipidated SCG was investigated in this study. Hydrolysis of SCG was carried out with the use of sulfuric acid (3–5 %v/v) as hydrolyzing medium, over a period of 30–180 min at a solvent to solid ratio of 10 mL/g at 95 °C. The optimum yield (26 and 31 g/g) and recovery (86 and 78 %) of the available reducing sugar was achieved at a local optimum employing an acid concentration of 4 % and a hydrolysis time of 120 min. Lipids were recoverable from the hydrolyzed biomass residue and bound lipids were also released through the hydrolysis process resulting in a recovery of over 100 %. This approach may potentially reduce production steps, avoiding energy intensive process for removal of water content in SCG.

Beschreibung: The energetic utilization of biogas, a gas mixture consisting mainly of CH 4 and CO 2 via the reforming or the dry reforming of methane reaction is of enormous interest as it converts these two greenhouse gases into synthesis gas (H 2 /CO mixtures). Nickel based catalysts have been extensively studied for both reactions, as they are highly active, but they suffer from fast deactivation by coking that can even lead to reactor blocking. It is thus desirable to learn more about their coking behavior, and their structural and catalytic stability. In this work, un-promoted and promoted with 6.0 wt% MgO or CaO alumina supported nickel catalysts (8.0 wt% Ni) were studied for the biogas reforming reaction. Supported nickel catalysts were synthesized following the wet impregnation method. The as synthesized Ni/Al 2 O 3 , Ni/MgO–Al 2 O 3 , Ni/CaO–Al 2 O 3 samples were characterized by various techniques such as XRD, SEM, ICP and BET. Catalytic testing experiments were performed in a fixed-bed reactor at temperatures ranging from 500 to 850 °C and a feed gas mixture with a molar CH 4 /CO 2 ratio of 1.5 simulating an ideal model biogas. It was concluded that the Ni/MgO–Al 2 O 3 and Ni/CaO–Al 2 O 3 catalysts exhibit higher values for X CH4 , X CO2 , Y H2 compared to the ones of the Ni/Al catalyst for temperature ranging between 550 and 750 °C, while the opposite is evidenced for T 〉 750 °C. It was also evidenced that the presence of magnesium or calcium oxide in the support ensures a quite stable H 2 /CO molar ratio approaching to unity (ideal for the produced syngas) even for low reaction temperatures.

Beschreibung: Matrices of FCC catalysts with different content of alumina and the compound catalysts prepared with them including Y zeolite were used to upgrade bio-oils from pine wood sawdust and soybean shell. The biomasses were selected according to their different lignin content which results in very different proportions of phenolic compounds (coke precursors) in the respective bio-oils. The bio-oils were produced by fast pyrolysis and the vapours were immediately upgraded over a fixed bed of catalyst at 550 °C using a mass catalyst/bio-oil relationship of 3.5. In terms of hydrocarbon yield, the matrices were more effective in deoxygenating pine wood sawdust bio-oil and the compound catalysts in deoxygenating soybean shell bio-oil. These differences can be the consequence of the different compositions of the bio-oils which, in the case of pine wood sawdust, includes a significant concentration of phenolic ethers which form coke on the matrix and the external surface of the zeolite, thus preventing lighter compounds from accessing the micropore system of the compound catalysts. Pine sawdust bio-oil produced more coke than soybean shell bio-oil; in the case of compound catalysts, coke deposited preferentially on the catalyst matrix, thus decreasing its mesopore specific surface area up to 65 %.

Beschreibung: Ionic liquid (IL) based pretreatment of lignocellulosic biomass for facilitating efficient enzymatic saccharification has emerged as an environmentally benign approach that offers several advantages over conventional strategies. However, residues of ionic liquid left in the pretreated biomass may cause inactivation of saccharifying enzymes thus, necessitating the requirement of ionic liquid-stable enzymes. Cost-effective production of industrial enzymes is always desired to enhance the overall process economy. Current study reports IL-stable cellulase production from a newly isolated bacterium Bacillus subtilis G 2 . Design of experiment (DoE) based on response surface methodology was used in sequential manner for optimizing cultural and environmental variables to enhance cellulase production by 2.66-fold. IL-stable cellulase was used for saccharification of IL-pretreated pine needle biomass (PNB) with 1-ethyl-3-methylimidazolium methanesulfonate in a consolidated single pot process i.e. one pot consolidated bioprocess (OPCB). The saccharification efficiency of 23.57 % was observed under OPCB. The hydrolsate obtained was fermented by dual culture of yeast i.e. Saccharomyces cereviasie NCIM 3078 and Pichia stipitis NCIM 3497, and a yield of 0.092 g ethanol/g of PNB was obtained with fermentation efficiency of 25.62 %. This study is first ever where-in IL-stable cellulase production is accomplished using agroindustrial residues by employing DoE, and assessed for its application potential under OPCB for saccharification of IL-pretreated PNB. IL-stable cellulases would not only preclude expensive washing step following IL-pretreatment of biomass, but their application in a consolidated single pot process (OPCB) offers numerous technoeconomic advantages over conventional multi pot processes. Graphical Abstract Production of ionic liquid (IL) tolerant cellulase from Bacillus subtilis G 2 was enhanced by 2.66-fold using response surface methodology. Cellulase was assessed for its saccharification potential on IL-pretreated pine needle biomass under one pot consolidated bioprocess, and the hydrolysate was fermented to ethanol using Saccharomyces cereviasie and Pichia stipitis .

Beschreibung: In this paper the potentiality of combined heat and power production by thermochemical conversion of meat and bone meal (MBM) was investigated in a scenario related to Italian technical, socio-economic and strategic situation. A model for the steam and air gasification of MBM was developed using commercial software. The model was validated through a comparison of the predicted results to literature data. Sensitivity analyses were carried out to identify process conditions that provide highest efficiency. Considering an input flow rate of MBM of 100 kg/h, optimal parameters of gasification have been identified with equivalence ratio and steam/biomass ratio equal to 0.2 and 0.4, respectively. The produced dry syngas is 165.41 Nm 3 /h, with a LHV of 5.72 MJ/Nm dry 3 . The syngas was fed in a micro gas turbine simulation routine. This was previously validated by available data about commercial micro gas turbine. Useful information about global efficiency was obtained together with an economic analysis that frames the matter, in order to evaluate the pay back period and the net present value.

Beschreibung: This paper describes the preparation of a biobased catalyst derived from residual Jatropha curcas cake using a combination of low-temperature conversion and chemical treatment to be applied for epoxidation of vegetable oil. The catalyst was characterized and its performance for epoxidation of cottonseed oil was evaluated and compared with the cationic resin VPOC 1800. After 60 min of epoxidation reaction, the results showed that VPOC resin catalyst presented yields (conversion of double bonds to oxirane rings) of about 34 % and biochar catalyst had yield of 14 %. Both catalysts presented high selectivity to bis-allylic hydrogen attack and elimination of 95 % of conjugated double bonds. The biochar catalyst presented higher activity than VPOC 1800 resin catalyst. On the other hand, the VPOC 1800 has better reusability.

Beschreibung: The main objective of this experimental work is to analyse the effect of recycled aggregates (RA), on the basis of the study of the various qualities, of the physical, mechanical and durability properties of high performance concrete (HPC). Five types of recycled aggregates: three coarse RA sourced from parent concretes of 100, 60 and 40 MPa, as well as one coarse mixed recycled aggregate and one fine ceramic waste aggregate were used as replacement for natural aggregates (NA). Two types of coarse NA and two types of river sands were employed for concrete production. On the basis of the findings of our research it was determined that the reduction in quality and the increase in the amount of RA substitution produced a decline in the properties of HPC. According to our analysis of the mechanical properties, a 100 % replacement of coarse NA for recycled concrete aggregates can be employed, providing the RA has been sourced from a 60 MPa minimum-strength concrete. Nevertheless, durability behaviour was greatly influenced by the use of RA, and consequently replacement ratios of high quality RA should be reduced to 50 % to achieve similar behaviour patterns to those of NA concrete. Moreover, severe reductions of RA qualities (sourced from 40 MPa strength concretes or mixed waste) only permitted 20 % replacement ratios on HPC production. However, those concretes containing fine ceramic RA (up to 30 %) reached higher compressive strength, higher chloride-ion penetration resistance and higher improvements of durability properties at longer ages than those concretes produced using NA concrete.

Beschreibung: Several abundant agri-food wastes, including lemon peels, olive leaves, onion solid wastes, red grape pomace, spent filter coffee and wheat bran, were used to test the efficiency of some novel glycerol-based natural eutectic mixtures to extract polyphenolic compounds. Extractions were performed under specified ultrasonication conditions and the eutectic mixtures, tested as 90 % (v/v) aqueous solutions, were glycerol:choline chloride, glycerol:sodium acetate and glycerol:sodium–potassium tartrate:water, with corresponding molar ratios of 3:1, 3:1 and 5:1:4. The latter two mixtures are reported for the first time. Water and 60 % (v/v) aqueous ethanol were also used as control solvents. The results obtained evidenced that glycerol:choline chloride exhibited high efficiency, which was comparable or even surpassed that of aqueous ethanol, but in some instances the same was observed for glycerol:sodium acetate too. In general, glycerol:sodium–potassium tartrate:water displayed lower efficiency in extracting polyphenols. The data also suggested that extracts with high polyphenol concentration may also possess higher antiradical activity and reducing power. The findings of this study were interpreted on the ground of assumptions regarding the polarity of the eutectic mixtures tested.

Beschreibung: In the present work, a continuous process was developed aiming at the production of bio-based hydrogen-enriched methane, from waste glycerol (WG) in a two-stage reactor system. In the first step, biohydrogen production was studied, using an attached mixed acidogenic consortium in an up-flow column bioreactor. Cylindrical porous ceramic beads with a surface area of 600 m 2 L −1 were used as attachment matrix of bacterial cells. The hydrogen yield, the substrate consumption and the distribution of soluble metabolites were investigated for two different substrate concentrations in the feed, i.e. 20 and 25 g WG/L. SEM pictures of the biofilm formed on the ceramic beads revealed that bacilli dominated in the reactor. Subsequently, RISA methodology showed that Klebsiella sp. and Clostridium sp. were among the dominant microorganisms. In parallel, a methanogenic reactor was started up and operated in continuous mode using initially commercial glycerol, and subsequently WG as carbon sources. In the sequel, the effluent of the hydrogenic reactor was fed to the methanogenic reactor (constituting thus the second stage in a two-stage process), and the effect of organic loading on the methane yield was studied. It was shown that the reactor managed to generate up to 73 % of the theoretically expected methane based on COD removal, corresponding to 256.0 ± 2.6 L CH 4 /kg WG. Moreover, simulation of the experimental data of the methanogenic reactor via the Anaerobic Digestion Model ADM1 revealed that the model was able to successfully describe the performance of the digester, even under dynamic conditions.

Beschreibung: Purpose Biochars are carbon-rich products derived from biomass through pyrolysis, and are useful for soil fertility enhancement and carbon sequestration. Most agricultural and forestry residues could be used for biochars production. In this study, biochars were produced from rice straw, bamboo culm, and reed straw under different pyrolysis temperatures. The physiochemical and morphological properties, and PAHs content of biochars were investigated for determining the effect of protective gas and pyrolysis temperatures on biochars under different pyrolysis processes. Method Rice straw, bamboo culm (8 years old), and giant reed straw were used in this study. These three organic materials were converted into biochars by slow pyrolysis using a lab-scale fixed bed pyrolysis reactor. Treatment temperatures of slow pyrolysis were 400, 500, 600 and 700 °C with or without the application of high purity nitrogen (〉99.999 %) as the protective gas. Results We found that the high-temperature pyrolysis produced lower biochar yield (25.84–28.84 %) than the low-temperature pyrolysis (29.44–34.4 %). However, the BET and C content of biochar under the high-temperature pyrolysis process was higher. The low H/C and O/C ratios of the biochars produced at higher temperature pyrolysis, was 0.08–0.10, 0.01–0.22, respectively, which showed that the carbon in these biochars was unsaturated. The PAHs content decreased with increasing pyrolysis temperature. Bamboo culms pyrolysed at 700 °C had the lowest concentration of ∑ 16 PAH (10.06 μg kg −1 ). Conclusion The pyrolysis temperature significantly affected the properties of the resultant biochars ( P  〈 0.05) while the protective gas did not ( P  〉 0.05).

Beschreibung: The use of alternatives, especially recycled materials, as substitute to naturally mined aggregates in concrete is an issue that is garnering more consideration with respect to the construction industry. This research contribution presents work in which bottom ash from a waste to energy facility was used as a partial aggregate replacement in Portland cement concrete (PCC). Compressive strength testing of specimens demonstrated a decrease in strength with increasing ash replacement percentages. This effect was significantly larger for the samples containing 〈9.5 mm ash fraction, this was attributed to the reactivity of the aluminum in the ash. The effect of aging the ash on concrete properties was assessed through an accelerated carbonation experiment. Carbonation was found to have little effect on the strength and durability properties of ash-amended PCC. Ash-amended concrete containing the larger ash size fraction was able to meet set design strengths at low replacement percentages (25 %).

Beschreibung: The present study focuses on the exploitation of food industry waste for hydrogen and methane production, via biological processes. Fermentative hydrogen production in an anaerobic up-flow column reactor (AUFCR), using indigenous microbial species and fed with the soluble fraction of the waste coming after an extraction procedure, was investigated at different Hydraulic Retention Times (HRTs) in the range of 12–2 h. The highest hydrogen production rate (2.94 ± 0.37 L H 2 /L/d) was obtained at the HRT of 2 h, while the highest yield of hydrogen produced per mol of consumed carbohydrates, expressed in glucose equivalents was achieved at the HRT of 12 h (0.14 ± 0.01 mol/mol). Methane production via anaerobic digestion (AD) in a CSTR—type reactor was also assessed, using the whole diluted food industry waste (without extraction). The HRTs tested were 20, 15 and 10 days, while when the reactor operated at the HRT of 10 days, the feeding medium was also thermally treated, in order to assess the effect of pretreatment in AD. The maximum methane production rate (0.24 ± 0.02 L CH 4 /L/d) was observed for the HRT of 10 days and thermally treated substrate, while the maximum methane yield was obtained at the HRT of 15 days (247.9 ± 0.15 L CH 4 /kg waste). The IWA ADM1 model was finally used to predict the anaerobic digesters’ behavior through the operational period, resulting to a quite satisfactory simulation for a wide range of operational conditions.

Beschreibung: The generation of waste by the paper industry has attracted great attention over the last decades among other reasons because the demand for recycled waste paper has considerably increased. As the paper industry is closely intertwined to the rest of industries in the production system, its activity exerts both a direct and indirect influence on the volume of waste generated by its supplier industries. The purpose of this study is to shed some light on the evolution of the volume of waste generated by the suppliers of the Spanish paper industry over the period 2005–2010 using an Economic Input–Output Life Cycle Assessment Model. In particular we focus on the evolution of the volume of waste generated by firms of the own paper industry. We employ data from different waste surveys conducted by the Spanish National Statistics Institute and input–output tables extracted from the World Input–Output Database. The results obtained show that the waste generated by suppliers amounted to 1250 thousand tonnes in 2010, an important volume if we take into account that the waste generated by the paper industry in 2010 amounted to 1739 thousand tonnes. The analysis of the evolution of the waste generated by suppliers reveals that there is a high degree of concentration, both in terms of industries and in terms of waste categories. In addition, the decrease in the volume of waste generated by supplier firms within the own paper industry reflects not only the growing importance of recycled paper as raw material for paper-making but also the important investments in technology made by this industry in Spain.

Beschreibung: Feathers are recalcitrant wastes produced by the poultry industry. Considering potential environmental hazards and the need for energy conservation/recycling, adequate approaches are demanded for feathers reclamation. Microbial conversion is an interesting alternative from both technological and economical perspectives. Therefore, 15 bacterial strains were isolated from a site containing waste feathers, and evaluated for proteolytic and keratinolytic potentials. From these bacterial isolates, seven produced extracellular proteases in milk agar plates, also demonstrating the ability to grow on feather meal agar plates, preferentially at pH values from 7 to 9, and at 30–37 °C. The isolate named CL33A displayed higher efficiency for feather degradation in qualitative assays, and selected for studies in feather broth (FB), a medium containing whole feathers (10 g/L) as the sole source of carbon, nitrogen and energy. CL33A degraded 29, 75, and 95 % of the feathers in FB, after 96, 144 and 216 h of growth, respectively. Feather degradation was corroborated by increases in soluble protein concentration and medium pH. Production of proteolytic enzymes reached maximal values after 216–240 h of growth on FB, and CL33A also produced proteases when cultivated in feather meal, peptone, and soy protein isolate. Through 16S rRNA gene sequencing, this feather-degrading isolate was identified as Bacillus sp. CL33A. Bioprocessing could be a suitable technology aiming the management and valorization of feathers/feather meal, due to the production of protein hydrolysates and also proteolytic enzymes that could be used as important biocatalysts.

Beschreibung: Phosphorus is a non-renewable essential element for plant’s nutrition, while it is considered also as the primary nutrient responsible for the eutrophication of inland surface waters. Therefore, the removal and recovery of phosphorus for potential reuse as fertilizer from wastewaters is currently considered as an issue of high priority. This study examines the content and the bioavailability of phosphorus in the phosphate precipitates/solids produced by the treatment of secondary effluent at the wastewater treatment plant “AINEIA”, near Thessaloniki (N. Greece). Initially, batch precipitation tests were conducted for collecting the respective ferric phosphate precipitates, after the direct addition of dissolved Fe(III) solution. Subsequently, the application of “Rapid Small Scale Column Tests” was performed by implementing iron oxy-hydroxides (FeOOH) as adsorbent medium. When the residual concentration of the column reached the (expected by legislation) disposal limit of 1 mg P- \( {\text{PO}}_{4}^{3 - } \)  L −1 , the column was regenerated and phosphates were recovered from the regeneration solution either as calcium, or magnesium insoluble salts. The phosphorus bioavailability tests revealed that phosphorus release was satisfactory from calcium (35 mg P kg −1 soil increment in acidic samples), or magnesium (16 mg P kg −1 soil increment in alkaline samples) precipitates. On the contrary, the content of phosphorus in soil after the addition of ferric phosphate precipitates was found to increase insignificantly (7 mg P kg −1 soil) and only in the alkaline samples. The respective phytotoxicity tests showed that all examined precipitates can be considered as non-toxic for higher plants, as they did not inhibit their seed germination, neither root elongation, with the only exception of alkaline soil samples with Lepidium sativum seeds, where a 20 % decrease was observed.

Beschreibung: In Portugal, where soils have a very low topsoil organic matter content, the use of sewage sludge (SS) as organic soil improvers seems an attractive option, because it would enable organic matter, N, P, K and other nutrients to be recycled. However, the risk of this practice must be properly assessed. The aim of this study was to evaluate the potential risk of the use of dewatered and composted SS as soil amendments. For this purpose, SS from two different wastewater treatment plants (SS1 and SS2), and a compost produced from SS and agricultural wastes (AWSSC), were characterized for their total metal concentrations, organic contaminants and indicator pathogens, and used in a pot experiment with three application rates, 6, 12 and 24 ton dry matter/ha, cultivated with a hybrid variety of sorghum and Sudan grass ( Sorghum bicolor × Sorghum sudanense var. Rocket). SS1 and AWSSC met the legal requirements to be applied to soils, but SS2 had a high content of pathogens, which compromised its use. Both dewatered SS had a marked beneficial effect on plant production and on soil nutritional characteristics, more pronounced than in the case of AWSSC application, without a significant increase in total and in mobile metals concentration in soils. Bioaccumulation factors for metals in plants were low, and their concentrations in the aboveground plant material were lower than the maximum tolerable level for cattle, used as a risk indicator of metal entry into the human food chain. However, it will be necessary, in future studies, to evaluate the potential risk of the observed increase in the mobilisable content of Cu and Zn in soil, as a consequence of the application of these organic materials.

Beschreibung: Constructed wetlands represent an increasingly expanding technology for treatment and reuse of poor quality waters and for the development of marginal areas. The exploitation of herbaceous biomass for biogas production may add further appeal to its adoption. Codigestion of lignocellulosic plant materials with pig slurry could meet the need for biomass hydration and possibly improve biogas yields. The objectives of this study were: (1) to evaluate the biomethanation potential of biomass from several species which are of interest for use in constructed wetlands, and its relationship with plant composition; (2) to evaluate the influence of codigestion of selected wetland species with pig slurry on methane production rate and yield. Biogas production was preliminarily measured in laboratory conditions using as substrates biomass samples belonging to 23 plant species coming from different environments. Eight of them were then tested for biogas production, alone or in codigestion with pig slurry (volatile solid ratio: 1/1). In monodigestion, CH 4 yields were on average 213 mL CH 4 g −1 volatile solids. Biogas production was positively related with N content and negatively with acid detergent fiber concentration and C to N ratio. The time for the joining of the maximum methane production was 25 % shorter and the amount of methane was 30 % higher for wetland biomass in codigestion with pig slurry than in monodigestion. The use of pig slurry as hydration medium for anaerobic digestion can improve the biomethanation potential of wetland biomass.

Beschreibung: Heterogeneous catalyst plays a vital role in this process, especially in view of cost and reusability. In the present study, a useless material such as waste animal bone was employed as support for calcium oxide impregnation. CaO was impregnated on the pre-treated waste sheep bone as an active component in different loading levels. The catalyst was then characterized and tested in reaction in similar conditions as follows: atmospheric pressure; reaction temperature: 60 °C; methanol/oil molar ratio: 12:1; catalyst weight (based on oil weight): 5 % and reaction time: 5 h, under vigorous stirring. When 5 wt% of CaO, based on support weight was impregnated, maximum conversion of 95.18 % was obtained and also the catalyst was recoverable. On the other hand, conversion of 49.51 % was obtained when the same amount of CaO was used without support and the catalyst was also non-reusable. Moreover, reusability tests showed only a slight decrease in catalyst activity.

Beschreibung: Kolkata city sewage purification process is rapid, extremely efficient and the process is operated in single pond systems at East Kolkata Wetland (EKW) in a highly sustainable manner. However, the underlying mechanism remains unclear. Since microbial activity plays vital role in wastewater purification, an understanding of the microbial community structure and their functions during purification is crucial. Therefore, we investigated the microbial community structure at different phases of this purification process. To unveil the microbial community structure, we performed 16S rDNA-based community analysis. The microbial community was found to be composed of methane producing, sulphate reducing, ammonia oxidising, nitrifying, denitrifying, phosphorus accumulating and other types of microorganisms. Results also showed that microbes with versatile metabolic potential grow at different phases of purification process and the microbial diversity and complexity decreases considerably with the progression of purification. Beside this, studies on the distribution of microbial population reveals that the community achieves more stability at later phases of purification. Thus, the current study documents the variations in microbial community structure during wastewater purification in single pond unit at EKW and provides an insight into the underlying mechanism of this type of unique process.

Beschreibung: Reclamation of landfills and dumpsites requires detailed technical and economic evaluation of actual and potential pollution at the site, including detection of the main contaminants, their concentration, chemical stability and mobility in the environment. Contamination with metallic elements and metalloids is among the most important problems that limits recultivation of landfills and dumpsites and reuse of landfilled materials. This study was implemented at the Kudjape Municipal Landfill, located on Saaremaa Island in Estonia. The Kudjape Landfill is a partly closed landfill recultivated by covering it with a layer of a fine fraction of landfill material after the landfill mining operations. The fine fraction was derived at the site by sorting the landfill material (i.e., disposed waste) using mechanical screening, manual sorting and sieving. Obtained relatively homogeneous material, consisting of particles smaller than 10 mm, was defined as a fine fraction of waste. Samples from the fine fraction at different depth were collected and analyzed. Metal mobility was assessed after the sequential extraction. Results revealed that such elements as Zn, Mn, Mg are found in various fractions; Fe, Cd, Cr—mainly in residual fraction; Cu, Pb, Ni, Ba, Co and Rb mostly in fractions of residuals and reduced compounds, but they are presented in larger proportion of acid and water soluble fractions. Slight interconnection of detected parameters and sampling depth was revealed. Sequential extraction of elements in the fine fraction suggested the valorization of waste and confirmed that such landfill material can be successfully used as a landfill-covering layer under the specific engineering circumstances.

Beschreibung: With the aim to utilize deoiled rice bran, an agro-industrial waste, as a feedstock for the co-production of multiple carbohydrases, a fungal strain was isolated which could utilize DORB to co-produce a consortium of cellulases, hemicellulases, pectinase and amylases and was named as Aspergillus niger P-19 after molecular identification. Further, optimization for the co-production of all the enzymes was carried out by one factor at a time approach. Time profile studies of the production of enzymes revealed that 5th day of incubation was best suited for the extraction of enzymes. An initial solid to moisture ratio of 1:1.5 and an inoculum size of 5 × 10 7 spores gds −1 were found to be optimum for maximum productivities. Enzyme yields were significantly improved with the exogenous supplementation of carbon source, nitrogen source, surfactants and lignocellulosic inducers. This is the first report of its kind where DORB has been utilized for the co-production and co-optimization of eight different enzymes which can have a potential application in biofuel industry as the enzyme preparation could effectively hydrolyze steam pre-treated DORB releasing a total reducing sugars of 356.17 ± 9.58 mg gds −1 .

Beschreibung: This paper presents the results of an experimental study of the effects of biocyaniding with dried cassava leaves obtained from Manihot spp. with BaCO 3 energizer. These are processed and used for the surface hardening of AISI 8620 steel. The case microstructures associated with carbo-nitriding are elucidated along with the effects of bio-cyaniding on the microstructure, microhardness and wear properties of the carbo-nitrided surfaces. The bio-processed waste (B-PW) was diffused (by heat treatment) into the surfaces of AISI 8620 steel using four different powder sizes (212, 300, 600 and 850 µm) and four different temperatures (750, 800, 850 and 900 °C). The resulting microstructures and micro-hardness profiles were then characterized along with the pin-on-disk wear behavior of the “case microstructures” that were formed. Superficial hardness and wear resistance were observed to increase with increasing particle size of B-PW and increasing pack cyaniding temperature. Finally, the wear mechanisms were also investigated by using scanning electron observations of the worn surfaces of the disks. The implications of the results are discussed for value addition to cassava waste.

Beschreibung: The feasibility of microwave-assisted extraction (MAE) and microwave-assisted enzymatic extraction (MAEE) for the polyphenols recovery from olive kernel and leaves was examined. The study revealed that applying MAE at 60 °C for 30 min, the extracts obtained from olive kernel had phenolic content 10.61 mg GAE/g raw material (dw) and antioxidant activity 10.40 mg Trolox/g raw material (dw) and the extracts obtained from olive leaves had phenolic content 28.00 mg GAE/g raw material (dw) and antioxidant activity 23.40 mg Trolox/g raw material (dw), respectively. By applying MAEE at 60 °C for 30 min, the extracts obtained from olive kernel had phenolic content 10.37 mg GAE/g raw material (dw) and antioxidant activity 15.93 mg Trolox/g raw material (dw) and the extracts obtained from olive leaves had phenolic content 29.52 mg GAE/g raw material (dw) and antioxidant activity 26.20 mg Trolox/g raw material (dw), respectively. Similarly, applying conventional extraction at 60 °C for 1 h, extracts with phenolic content 11.41 mg GAE/g raw material (dw) and antioxidant activity 9.69 mg Trolox/g raw material (dw) were obtained from olive kernel and extracts with 34.53 mg GAE/g raw material (dw) and antioxidant activity 27.94 mg Trolox/g raw material (dw) were obtained from olive leaves, respectively. HPLC analyses of phenolic compounds of extracts proved that the use of enzyme on extraction process leaded to valuable recovery of phenolic compounds. The predominant phenolic compounds in olive kernel and leaves extracts were oleuropein, hydroxytyrosol and rutin. Moreover, in order to protect the phenolic compounds’ properties, the extracts of olive kernel and leaves with high antioxidant activity were encapsulated in maltodextrin by freeze-drying technique. The final encapsulated polyphenolics’ products were evaluated in terms of hygroscopicity, solubility, moisture content and microencapsulation efficiency (MEE%). The MEE% varied from 82.39 to 92.12 % and from 87.98 to 91.06 % for olive kernel and leaves formulations, respectively. The encapsulation improved the moisture content, solubility and hygroscopicity of the encapsulated products. Concluding, the MAEE method being environment-friendly was efficient for the polyphenols recovery, while the polyphenols having significant antioxidant activity can be used as a source of potential antioxidant. Importantly, the use of olive kernel and leaves for such polyphenolic products reduces the impact of olive oil production on the environment.

Beschreibung: The goal of this study was to screen microorganisms that are potential producers of cellulases, determine optimal conditions for production of these enzymes, and scale up the process, using empty fruit bunches (EFB) as a substrate. Strains of Trichoderma sp., Aspergillus niger , Phanerochaete sp., Ganoderma sp. and Lentinus sp. were evaluated for their ability to produce cellulolytic enzyme complexes under submerged with suspended solids fermentation (SSdF). Among these microorganisms, Phanerochaete sp. (PH-HD), which is already known to be a good producer of lignolytic enzymes, presented the highest capacity for cellulase production. The highest level of cellulase production by Phanerochaete sp. was observed on the 4th day of fermentation at 28 °C and pH 5.7, reaching a value of FPase activity of 364 IU L −1 using 15 g L −1 of EFB as a carbon source, 2 g L −1 of urea as a nitrogen source, 4 g L −1 of KH 2 PO 4 , and microcrystalline cellulose Avicel ® PH-101 as an inducer (2 g L −1 ). This study shows the great potential of Phanerochaete sp. for producing cellulolytic enzymes, as well as the feasibility of using EFB under suspended solids fermentation in the production process.

Beschreibung: Industrial tomato processing by-products are intended mainly for animal feed or fertilizer, though they can be used for the recovery of valuable constituents. Carotenoids constitute an important component of these by-products, well credited with important health-promoting functions. This study examined the effect of several organic solvents (hexane, ethanol, acetone, ethyl acetate, ethyl lactate and their mixtures), and extraction temperature on the recovery and isomerization of carotenoids from tomato processing by-products. Another area under investigation was the stability of carotenoids, as affected by drying and storage conditions of tomato by-products. HPLC–DAD analysis was applied for the efficient separation and analysis of the carotenoids and their cis -isomers. The highest extraction yield was obtained with ethyl lactate (203.6 μg/g dry by-product) followed by hexane–ethyl acetate mixture with a considerably lower yield (36.1 μg/g dry by-product). The identified carotenoids in all solvent extracts followed the order: lycopene ≫  β -carotene 〉 lutein, in their predominant trans -configuration. Among the identified isomers, 5- cis lycopene and 15- cis - β -carotene were the most abundant in all extracts. The increase of extraction temperature increased the total lycopene concentration in all extracts, whereas cis -isomers remained lower than 8 % in most solvents. A steadily high percentage of cis-isomer (≈30 %) was observed in ethyl lactate extracts, independent of temperature. Conversely, the increase of extraction temperature induced a reduction in total β -carotene and total lutein concentration in all solvents, while cis -isomers were not detected. Drying or even cold storage of the raw material led to decreased yields, and affected lycopene isomerization with a considerable increase of cis -isomers.

Beschreibung: The purpose was to investigate the treatability of a wastewater from a biodiesel production industry under (1) aerobic conditions, using domestic activated sludge as inoculum; (2) anaerobic conditions, using sludge from an anaerobic domestic wastewater treatment digester; (3) utilization of wastewater for biogas production. The aerobic biodegradation batch tests were conducted in reactors with a working volume of 1.0 L, according to Zahn Wellens’s methodology proposed by the Organization for Economic Co-operation and Development. The anaerobic treatability was determined by the methodology proposed by Field et al. (4º Seminario de Depuración anaerobia de aguas residuales, Valladolid Universidad, Secretariado de Publicaciones, Valladolid, 1988). Based on the results of anaerobic biodegradation, four new reactors with a working volume of 1.0 L were inoculated to evaluate the biogas production potential. The experiments showed that wastewater can be degraded under aerobic conditions with no lag-phase. COD maximum concentration of 780 mg L −1 could be metabolized aerobically. The anaerobic biodegradation only started after the adaptation phase (3 days). After 28 days, it was possible to achieve removal efficiencies above 90 % for the conditions applied in anaerobic tests. It was possible to obtain 114 mL of biogas for the highest influent COD concentration of 800 mg L −1 and F/M ratio = 0.25.

Beschreibung: In this study, coir fiber board was reinforced with banana stem fiber to improve the mechanical properties of the board. Different ratios of banana stem fiber and coir fiber were mixed to make composite boards. These ratios had different effects on the physical (TS) and mechanical (MOR, MOE, and IB) properties of the particleboard composites. Banana fiber improved the MOE and MOR of the hybrid coir fiber boards. However, the internal bond strength (IB) of the artificial board decreased and the thickness swelling from water absorption increased. When the ratio of coir fiber to banana stem fiber was 8:2, all performance aspects of the artificial board reached the requirements of the structure in dry conditions based on standard GB/T4897.4 (2003). SEM and FTIR, and SSA were used to analyze the fiber micro-structures, and bonding mechanisms of the particleboard were examined. These results confirmed that a novel hybrid particleboard composite could be produced. The traditional craft of coir fiber board was changed, which was made from coir fiber and epoxy resin through hot-pressed. The excellent performance of the coir fiber/banana stem fiber particleboard composites suggests that they are suitable for non-load-bearing partitions and outdoor building materials.

Beschreibung: After acid hydrolysis with \(\hbox {H}_2\hbox {SO}_4\) from olive pruning, subsequent fermentations were carried out in order to compare two non-traditional yeasts: Candida guilliermondii and Pichia stipitis . During the fermentations, sugar uptake as well as ethanol and xylitol production were determined. However, both yeast employed for the biotransformations showed different behaviours; C. guilliermondii produced ethanol from D -glucose and xylitol from D -xylose but, in contrast, P. stipitis only was able to produce ethanol from hexoses and pentoses although, due to the inhibitors amount (acetic acid and polyphenols mainly), it required a detoxification step. To solve this problem, activated charcoal treatment as well as a vacuum evaporation process (concentration ratio 2.7) were performed as physical detoxification methods with positive results. The maximum ethanol and xylitol yields ( \(Y_{P/S}\) ) (calculated on consumed sugars) obtained with C. guilliermondii were 0.38 and 0.31 kg \(\hbox {kg}^{-1}\) respectively; while P. stipitis was able to produce 0.33 kg of ethanol per kg of fermentable sugar.

Beschreibung: The objective of this study was to examine the process of aqueous extraction of organics and phenolics from winery wastes (grape marc and wine lees) and the anaerobic digestion of the extracts using a pilot-scale anaerobic digester. Samples of grape marc and wine lees were extracted with tap water under controlled laboratory conditions at different solid/liquid ratios 1:3, 1:5 and 1:10 (w/w). The extracts were characterized in terms of organic matter composition, and phenolic content. Following this, a 3 m 3 stirred tank digester, inoculated with anaerobic granular sludge, was installed and operated at the premises of a winery using original grape marc and wine lees extracts. The recovered extracts were characterized by a high chemical oxygen demand (COD = 20–30 kg m 3 ) and low concentration of phenolics (〈100 mg L −1 ). They displayed high anaerobic degradability with a biogas yield of 0.50 m 3  kg −1 COD, a methane content of 72 % and an effluent COD concentration between 0.6 and 1.6 g L −1 . Based on a preliminary design and cost analysis it was demonstrated that for a medium sized winery (1000 tn grapes per season) a 40 m 3 compact anaerobic digester suffices, while the payback period is around 6–7 years. Aqueous extraction of organics from winery wastes enables the recovery of readily degradable COD with low phenolic content. Generation of biogas from the recovered extracts was highly efficient using a compact anaerobic digester.

Beschreibung: Degradability of degradable / biodegradable polymers was investigated under landfill conditions. Real conditions experiment was conducted to study the biodegradability. The research was conducted from 2012 to present. Research samples were bags commonly available in Europe recovered directly from the market (biodegradable, degradable or other designation). In addition, 2 bags certified for composting were chosen. In total, the experiment contained 5 samples—4 bags and cellulose filtering paper as a control sample. The validity of the tests was confirmed in that positive control was biodegraded by more than 99 %. It was found that the high-density polyethylene sample with the totally degradable plastic additives and polyethylene sample labeled as 100 % degradable had not been decomposed and no degradation nor physical change had occurred; however, their color had changed. Samples certified as compostable biodegraded incompletely.

Beschreibung: The present paper presents a part of the research efforts of the laboratory of Metallurgy, National Technical University of Athens, Greece, aiming at developing a purely hydrometallurgical method, able to treat the zincferous dust, generated during the production of steel from scraps in Electric Arc Furnace (EAF), efficiently and economically and especially so for annual capacities lower than 50,000 tonnes of dust, for which the currently applied industrial methods are not economical. The proposed method is based on direct sulphuric acid leaching of the EAF dust and it succeeds to recover the valuable metals contained in it, such as zinc, lead and cadmium, converting the initially hazardous waste into a residue suitable to be fed to cement industry. The EAF dust sample, provided by a Greek steel plant, was initially leached with water, at certain conditions, to remove as much of the contained calcium as possible without co-dissolution of other metals. The washed dust was further subjected to three–stage leaching at atmospheric pressure, using sulphuric acid concentrations of 2N and 3N and temperatures 25 °C, at the first stage, and 95 °C, at the second and third stages. Total percent extraction values achieved were 97 % for zinc and 97 % for cadmium. Almost all lead, 99.7 %, remained undissolved as lead sulphate in the leach residues. It was shown experimentally that lead can be recovered as saleable lead sulphide while zinc can be recovered from the pregnant solution by solvent extraction with D2EHPA. Finally, based on the results, a conceptual flowsheet of the proposed integrated hydrometallurgical method for the treatment of EAF dust was established and is given.

Beschreibung: In this study, a semi-continuous photobioreactor was operated for the investigation of nutrient removal efficiency of a unialgal culture, Chlorella vulgarıs . Maximum nitrogen and phosphorous removal efficiencies of 99.6 and 91.2 % were achieved in the photobioreactor. The microalgal slurry obtained from the effluent of the photobioreactor was subjected to biochemical methane potential assay, after application of heat, autoclave, and thermochemical pretreatments to improve anaerobic digestibility and biogas production. Evaluation of pretreatment options indicated that heat pretreatment is the most efficient method in terms of enhancing anaerobic digestibility, at the chemical oxygen demand (COD) loading of 19 ± 0.5 g L −1 . This method increased the methane yield by 83.0 %, from 223 to 408 mL CH 4  g VS added −1 , compared to untreated microalgal slurry reactor with the same COD value. Among reactors with 35 ± 1.5 g L −1 initial COD concentration, autoclave-pretreated microalgal slurry was found to yield the highest methane value of 356 mL CH 4  g VS added −1 , which was 43.0 % higher than the value observed in the reactor fed with untreated microalgal slurry. The thermochemical pretreatment caused production of inhibitory compounds and resulted in lower biomethane production and COD treatment values, compared to untreated microalgae. Outcomes of this study reveal that coupled micro-algal and anaerobic biotechnology could be a sustainable alternative for integrated nutrient removal and biofuel production applications.

Beschreibung: Compatibility tests were conducted between synthetic oil and potential solid filler materials in a thermocline tank built at the PROMES-CNRS laboratory. These experiments consisted of placing the oil and the solid materials together in small crucibles (2.3 L) and performing compatibility tests at 300 °C and accelerated ageing tests at 330 °C for 500 h. The mutual influence of the oil and the solid materials was assessed through different measurements: X-ray diffraction and scanning electron microscopy. The influence of the solid on the oil was assessed by measuring thermo-physical and chemical properties. While no significant degradation of the oil is measured at 300 °C, at 330 °C, an increase in the oil degradation rate was observed. Its density, thermal conductivity and specific heat did not change, but its viscosity showed a significant increase. However, after accelerated ageing tests at 330 °C, the oil still shows good heat transfer performance. The solid crystalline structure did not change during the test but some of the samples seemed to absorb oil.

Beschreibung: Alternative glycerol treatment and valorization, could be a promising solution, contributing to the biodiesel production economy. Thus, the potential of electricity generation from pure glycerol, using a two-chamber microbial fuel cell (MFC), was evaluated. The effect of glycerol concentration in a range of 0.5–5.2 g COD L −1 on MFC performance was examined. In order to achieve a stable MFC performance and a high power density, special attention was paid during the acclimation phase of the anaerobic consortium, which was performed using glucose, instead of glycerol, as substrate. The best performance of the cell was observed at a glycerol concentration of 3.2 g COD L −1 . At this concentration, the Coulombic efficiency (CE) was 34.1 %, the chemical oxygen demand (COD) removal efficiency was approximately 99 % and the maximum power density was 65.4 mW m −2 . Further increase of glycerol concentration to 5.2 g COD L −1 did not enhance the MFC performance, since the power density remained at 63.4 mW m −2 , while the CE and the COD removal efficiency decreased to 22.1 and 81 %, respectively. The experimental results showed that glycerol is a suitable and promising substrate for power generation, using a simple two-chamber MFC and that acclimation of anaerobic sludge using glucose as substrate, is a suitable procedure for securing a stable MFC performance, even at high glycerol concentrations.

Beschreibung: In real-life construction projects, the utilization of different types of waste derived aggregates can often be falsely considered as utilization, but in fact, it is merely dumping the potentially high value material from one site to another. For example, building highway noise barriers with waste derived aggregates cannot be considered as utilization. In this study, a more advanced approach was chosen in order to create aggregate like products from recovered municipal solid waste incineration (MSWI) bottom ash (BA) and thus potentially increase their value and image in civil engineering applications. MSWI BA from one waste incineration plant in Finland was first treated with a Dutch dry treatment technology called advanced dry recovery. This process separates non-ferrous and ferrous metals from MSWI BA and generates mineral fractions of different grain sizes. These mineral fractions may not be used separately, for example, in the unbound structural layers of roads due to the strict grain size distribution requirements of these civil engineering structures. Hence, different combinations were designed from these BA mineral fractions using the mathematical proportioning of aggregates. The aim was to create aggregate like products from this waste material for different structural layers (filtration, sub-base and base) of, for example, road and field structures. Three mixtures were chosen based on their correspondence to the grain size distribution requirements of natural aggregates and further analyzed in the laboratory from their technical, mechanical and environmental point of view. The leaching of chrome (Cr) and chloride (Cl − ) exceeded the Finnish emission boundary values for utilization of certain types of ashes in civil engineering. On the other hand, the technical and mechanical properties of these mixed bottom ash products were considered suitable to be used, for example, in the unbound structural layers of the interim storage field in a waste treatment center. In such location, the leaching potential of harmful substances can be further studied and verified in a larger scale.

Beschreibung: The study explored the potential of low-cost agro-industrial residues in the production of phytase from bacterial sources which was (1) active at high temperature and broad range of pH and, (2) can act as a supplement for animal feed in order to improve its nutritional efficiency. Optimization of various factors (incubation period, initial pH, inoculum age/size, and carbon/nitrogen source) under submerged fermentation resulted in 21.55-fold (0.431 U/ml) improvement in phytase (Phy-Ck) production from Citrobacter koseri PM-7 [isolated from the rhizosphere of black sesame ( Sesamum indicum )]. Under solid state fermentation using wheat bran, 9.372 U/g dry substrate of Phy-Ck production was obtained after 120 h of incubation. Partially purified Phy-Ck exhibited maximum activity at pH 5 and was stable in a pH (3–6) range by retaining more than 40 % of its activity after 3 h of incubation. Phy-Ck was optimally active at 70 °C. Ca 2+ was found to marginally stimulate Phy-Ck while, moderate to complete inhibition of enzyme activity was observed in presence of Mn 2+ , Mg 2+ , Ni 2+ , Li 2+ , Hg 2+ , Cu 2+ , and EDTA. Thermal inactivation kinetics of Phy-Ck at 50–63 °C in the presence of Ca 2+ led up to 12.33-fold improvement in half-life (t 1/2 ) and better values for thermodynamic parameters [deactivation energy (E d ), enthalpy (H) and entropy (S)]. The K m and V max values of Phy-Ck were 0.408 mM and 3.586 μmol/ml/min, respectively. Phy-Ck displayed good tolerance (up to 98.5 % activity) towards proteolytic enzymes (pepsin, trypsin, and chymotrypsin). Phy-Ck was able to dephytinize agro-industrial residues with concomitant liberation of inorganic phosphate and soluble protein. The study demonstrated valorization of agro-residues for production of phytase useful for feed industry.

Beschreibung: The elemental and chemical constituents of an active and a closed landfill were compared using Fourier transform-infrared (FTIR) spectroscopy, scanning electron microscope/energy-dispersive X-ray spectroscopy, and proximate analysis. The two landfills had similar major elemental constituents representing 96.5 and 98.4 % of elemental composition for the closed (O 〉 C 〉 Si 〉 Fe 〉 Ca 〉 Al) and active (C 〉 O 〉 Si 〉 Al 〉 Ca 〉 Fe) landfill samples respectively. The average concentration of Al was significantly higher ( p  = 0.024) in the active landfill, while Ca was significantly higher ( p  = 0.023) in the closed landfill. Cluster analysis revealed that similarities were more influenced by the level of composite degradation (more degraded/less degraded) than by depth or seasonal variations. Samples from both landfills showed FTIR absorption peaks that indicated mineralisation and stability of waste constituent. Active landfill samples showed distinguishing peaks at 3690 and 3619 cm −1 attributed to O–H vibration of clayey mineral (kaolin), while closed landfill samples were characterised by a carbonates peak at 873 cm −1 . For both landfills, the average ash content (〉51 %) of the waste was above the level considered suitable for energy recovery from waste. These findings inform strategic decisions in management of the landfills and in the determination of possible alternative uses for landfill waste.

Beschreibung: Vinegar residue (VR) is a by-product which produced by the process of vinegar production. To enhance the performance on methane production of VR and facilitate its resource utilization, sodium hydroxide (NaOH) pretreatment was carried out. Results showed that with the concentration of NaOH increased, the cumulative methane yield ascended first and then declined. At NaOH concentration of 3.0 %, the cumulative methane yield was 205.86 mL g VS −1 and improved 53.99 % comparing with the untreated VR. Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, and component analysis demonstrated the structural and compositional changes in VR after NaOH pretreatment. The results obtained in this study proved that NaOH pretreatment was really efficient for enhancing the capability of anaerobic digestion (AD) and increasing methane production. Through this technology, it not only provides a method to reduce the pollution to environment but also contributes to clean energy production. Meanwhile, the results of this research may serve as a promising and potential way for AD of VR in the future industrial applications.

Beschreibung: Biomass utilization for energy production purposes can play an important role to the global effort for mitigating the environmental burdens associated with the highly criticized fossil fuelled energy production. A significant potential of solid residues is produced in the agro-industrial sector and wood industry. This potential can be utilised for the production energy by means of pre-treatment and pelleting. This report aims to present the results obtained from the thermochemical characterisation of eight pellets derived from purely processed and blends of woody and agricultural residues biomass feedstock; walnut shells, three-phase olive pomace, exhausted olive husk, chemically untreated wood shavings, mulberry tree pruning, chemically untreated wood shavings—grape pomace blend. Analyses for the determination of total moisture, hydrogen, nitrogen, carbon and ash content, as well as the net calorific value were conducted following the standardized procedures of the 17225 standard series, in order to carry out a preliminary evaluation of the physical and chemical characteristics of the investigated pellets. Satisfactory results were obtained from all samples with regard to their energy content and the total nitrogen content. Ash content of the pellets was found within the acceptable limits for the majority of samples except for the pellets delivered from exhausted olive husk, mulberry tree pruning and the blend of grape pomace (85 vol%) and chemically untreated wood shavings (15 vol%).

Beschreibung: The global fruit and vegetable processing industry is growing steadily due to the population growth, the adopted healthier eating patterns by consumers, and the advancements in supply chain management and production processes. The present study is focused on the investigation of the waste and wastewater treatment practices taking place in the Greek sector of processing and preserving fruit and vegetables through a detailed examination of eleven industrial units related to this specific industrial sector. Among these units, two were associated with tomato processing and nine with the processing of peaches and apricots. Moreover, aiming at adding value to the Greek fruits and vegetables processing sector, waste and byproducts valorisation opportunities were identified through a comprehensive literature review. Based on the recording of the existing situation in Greece, it was observed that all industrial units operate biological wastewater treatment plants mainly applying the activated sludge process. Food industrial waste by-products derived from the operation of the units were mainly given as feed (e.g. the plant residues) or exploited for the production of energy (e.g. the fruit kernels). In addition, based on literature review, it was obvious that industrial food waste valorisation comprises a research area that has attracted great deal of attention over the last years resulting in significant advancements. Considering the above, in order to add value to the Greek fruits and vegetables processing industry, waste valorisation can be considered including technologies to recover valuable compounds. However, more efforts are needed to prove that such practices can work at a commercial level and that all operational and manufacturing issues have been carefully considered.

Beschreibung: The article presents research results on obtaining phosphorus suspension fertilizers on the basis of microbiologically activated sewage sludge ashes and Morocco phosphate rock. The fertilizers were manufactured with the use of a laboratory reactor, as well as an experimental pilot plant for liquid fertilizers production and then subjected to physicochemical properties tests that have allowed to asses the quality of the obtained products and to appoint new directions for further research on obtaining phosphorus suspension fertilizers on the basis of microbiologically activated renewable resources of phosphorus. The tests have confirmed that it is possible to produce phosphate fertilizer suspension by using the Bacillus megaterium for solubilization of phosphorus, and that the process is not complicated. However, obtained fertilizers are characterized by low P 2 O 5 content.

Beschreibung: The fertilizing potential of various agro-industrial wastes [compost (C), dehydrated manures (DM) and digestate (D)] on soil and crops growth were investigated. Soil properties as pH, electrical conductivity, water retention capacity and soil organic matter (SOM) were modified. Hence, SOM increase from 1.1 % in unamended soil to 2.3 and to 3.5 % in soils amended with (DM) and with (C) respectively. Also, microbial and respirometric soil activities were strongly improved, mainly in presence of DM and D. Tomato ( Lycopersicon esculentum ), Alfalfa ( Medicago sativa ), Wheat ( Triticum durum ) and Sorghum ( Sorghum bicolor ) were tested for the germination index and growth evolution in soil amended by various wastes. Plants grown in amended soils explained an improvement in crops growth, biomass and better productivities than crops grown in unamended soil and irrigated with water.

Beschreibung: Purpose Ionic liquids (ILs) have been found to be highly promising for lignocellulosic biomass pretreatment, due to their excellent abilities to dissolve biopolymers. However, they have found to inactivate enzymes. In previous studies, Cholinium-based ILs showed great compatibility with cellulases and thus were introduced for a combined-system. This study aims to find the optimum condition in order to achieve the maximum pretreatment-hydrolysis of empty fruit bunches (EFB). Methods Definitive screening design (DSD) was employed with seven factors that are thought to impact the process including pretreatment temperature, pretreatment time, hydrolysis time, enzyme loading, particle size, biomass loading, and IL/buffer ratio. DSD offered several solutions for optimization in which they were experimentally tested. Results The maximum sugar concentration (77 g/L) was obtained at 90 °C, 70–116 min of treatment, 36–42 h of hydrolysis, 40–62 Unit/g cellulase loading, 34–35 %, w/v) biomass loading, 220–450 μ particle size, and 10 % (v/v) IL to buffer ratio, respectively. The subsequent optimization by response surface methodology (RSM) revealed the temperature for treatment can drop to 75 °C while fixing the pretreatment time at 100 min. Around 75 unit/g of cellulase and 〉22.0 % (w/v) of the biomass could be loaded to achieve a minimum of 70.0 ± 7.83 g/L of sugar, equivalent to 0.38 ± 0.08 g glucose/g and 0.48 ± 0.05 g total reducing sugar/g dry EFB. Conclusions The locally produced cellulase (PKC-Cel) from Trichoderma reesei exhibited promising results in the single-step process and can be used as an efficient approach to be optimized for fermentation to bioethanol production. Graphical Abstract

Beschreibung: This paper aims to evaluate various pre-treatment methods to improve the release of phosphorus (P) in the liquid fraction after solid–liquid separation of digestate (input: (dairy) manure and organic biological by-products provided by the food industry). As such, the P recovery potential from the liquid fraction as concentrated fertilizer product can be increased, whereas soil organic carbon can be maintained through local recycling of the resulting thickened fraction. Four different mechanical pre-treatments (microwave heating, conventional heating, ultrasonic treatment, and orbital shaking) were tested in combination with the chemical dosing of three different acids (citric acid, formic acid, and HCl) down to pH 4, 5, and 6. The pre-treatments released 13–28 % soluble ortho-P relative to total P. When balancing the recovery efficiency with the acid costs, the addition of HCl down to pH 4 under microwave heating was most feasible. Nevertheless, if no pasteurization is required for fertilizer marketing, then orbital shaking (mixing in practice) with HCl addition may be more attractive.

Beschreibung: The potential of several agricultural wastes and by-products (wheat bran, oat bran, corn cob, brewer’s spent grain, malt sprout, artichoke stem, sugar beet pulp, olive seed, cotton stalk and hazelnut skin) was examined as the substrate for xylanase production by Aureobasidium pullulans Y-2311-1. Based on the screening studies, wheat bran was selected as the best substrate for further optimization studies. The effects of initial medium pH, temperature and incubation time on xylanase production in shake flask system were optimized by response surface methodology (RSM). The optimum levels of the process variables defined by the model (initial medium pH, 4.24; temperature, 30.27 °C; and incubation time 126.67 h) resulted in production of 85.19 U/ml xylanase. Taking the RSM optimized parameters in shake-flask scale into consideration; xylanase production was scaled up to bioreactor system with a working volume of 1.5 l. The peak of enzyme production was achieved after 126 h incubation that has previously been determined by RSM studies at shake flask level. Furthermore, the optimum levels of agitation and aeration in bioreactor system was found as 200 rpm and 1.5 vvm. Maximum enzyme production was close to 85 kU/l which could be translated into a productivity of 0.68 kU/l/h. No previous work considered the statistical optimization of xylanase production by A . pullulans on wheat bran and scale up of the bioprocess to a bioreactor system.

Beschreibung: The aim of this work was to study the thermal behavior of metakaolin-based geopolymer cements using sodium waterglass (NWG) from rice husk ash and waste glass as alternative alkaline activators. Metakaolin-based geopolymer cements were obtained by adding freshly prepared NWG and metakaolin. The geopolymer cements obtained using sodium waterglass from rice husk ash and the one obtained with sodium waterglass from the waste glass were treated at room temperature for 28 days and then heated at 200, 400, 600 and 800 °C. The results show that the metakaolin-based geopolymer cements lose their compressive strength from room temperature to 400 °C. At 600 °C, the compressive strength of geopolymer cements increases relative up to 200 and 400 °C. At 800 °C, the reduction of compressive strength of geopolymer cements is assigned to the total evaporation of the rest of structural water. However, it is higher than that measured at ambient temperature for geopolymer cement obtained using the sodium waterglass from waste glass but lower for the sample obtained with sodium waterglass from rice husk ash. The total mass loss of geopolymer cements obtained with sodium waterglass from rice husk ash and one obtained with sodium waterglass from waste glass are about 12.57 and 15.04 %, respectively. This suggests that geopolymer cement obtained using sodium waterglass from waste glass are more condensed geopolymer structure indicating that it could a very suitable material for fire resistant application. The results indicate that NWG from rice husk ash and waste glass could be served as suitable alternative activators for producing metakaolin-based geopolymer cements with high-temperature performance.

Beschreibung: An integrated process for collective recovery of phenolic compounds from olive mill wastewater (OMW) and grape pomace (GP), which would also benefit easier biodegradation of OMW in a further process, was developed. Response surface methodology was employed to optimize the process parameters. Treatment of GP with OMW resulted in the transfer of 64.41 % of total polyphenols contained in OMW to GP under the optimal conditions predicted by the model. In the following step, extraction of phenolic compounds in treated-GP with ethyl alcohol:water under the optimum conditions predicted by the model was performed and 11.97 mg g −1 phenolics was recovered. The total antioxidant activity of the recovered phenolics was 81 % (inh.).

Beschreibung: Informal waste management sector often sustains in a cliquish socioeconomic environment. The present study suggests that rather than keeping this sector marginalized, its significance should be recognized and efforts should be made for its integration with formal sector to introduce synergy. For a detailed assessment of the economic contribution of the informal waste management sector, a case study has been performed in Bahawalpur, a medium sized city of Pakistan. The study investigates the current recycling conduct of the society and scrutinizes the economic role of main stakeholders involved in recycling, including waste pickers, itinerant buyers and waste traders. The recovery activity is profitable for key stakeholders involved and generates a revenue of approximately 6.05 billion Rupees or 6 million USD/year. The outcome suggests that the informal waste management sector is proficiently involved in waste recovery activities and its integration with formal sector can work optimally at both ends. The guideline for enabling formal-informal waste sector integration has been evaluated under a recently developed tool known as “InteRa” (integration radar) rapid evaluation metric and visualization tool. Application of “InteRa” framework proffers a step-wise direction as it demonstrates the extent to which local situation is favorable, investigates the existing gaps and advocates necessary changes that need to be incorporated to achieve formal-informal sector integration in the study area.

Beschreibung: This paper describes the potential valorization of sludge waste generated from aquaculture using biofloc system for bioremediation purpose. Three sets of mesocosms were artificially contaminated by 5 % of crude oil (v/v) representing a control, inoculated mesocosm with a commercial hydrocarbonoclastic consortia and a treatment that correspond to the use of sludge from floc-forming consortia. Samples of each mesocosms were taken at 0, 2, 4, 7, 14, 21, 42 and 56 days as well as sediment background to assess abiotic losses due to hydrodynamic force and possible contamination of sediment by the three set of experiments. The results showed significant differences of hydrocarbons removal among the treatments when it was confronted with the different consortia communities exposed through the time and coursetimes. In terms of hydrocarbons removal all treatment reached removal ca. 60 % (w/w) of pollutants at the end of experimentation but the removal performance was different during the first 14 days. The significant results of this study were to support the hypothesis that indigenous bacteria can be used as bioremediation agent but needed more adaptation time compared to the mesocosms that have been inoculated by exogenous bacteria. Both hydrocarbonoclastic and sludge waste from aquaculture were shown to be readily active as starter for biodegradation. Such condition will be beneficial to the mitigation of future oil spills in the study area which are located in the narrow strait where maritime transportation is frequent.

Beschreibung: Although epoxy resin was developed from liquefied sustainable resources, such as wood, corn bran, bagasse, etc., the use of liquefied biomass for manufacturing high performance epoxy resin has been limited because of the effects of these materials on properties of epoxy resin were unclear. Thus, the liquefied reed-based epoxy resin was synthesized by glycidyl etherification between liquefied reed and epichlorohydrin in this study. The relationship between reed liquefaction behavior and thermodynamic properties of liquefied reed-based epoxy resin was investigated by Gel permeation chromatography (GPC) and Thermogravimetric analysis (TGA), as well as by determination of residue content, phenol content, epoxy index and mechanical performance. The results indicated that not only high content of bound phenol, but also broad molecular weight distribution of liquefied reed would widen molecular weight distribution of synthetic epoxy resin, which was a major cause of low adhesive shear strength and great thermal stability of cured resin.

Beschreibung: Low strength sodium hydroxide pre-treated rice straw was hydrolysed at two different solid loadings i.e. 10 and 15 % (w/v) with in-house cellulases (IC) produced by Aspergillus terreus along with commercial cellulases (CC) by using batch and fed batch hybrid simultaneous saccharification and fermentation process. Optimization of process parameters enhanced the crude cellulase activities i.e. filter paper, β-glucosidase and endoglucanase by 1.6, 2.7 and 2.2 fold in 6 days as compared to activities obtained on a single substrate i.e. rice straw. Out of four fed batch approaches, approach III (A-III) at 10 % solid loading yielded higher ethanol concentrations of 30.55 and 28.66 g L −1 by using thermo tolerant in-house yeast strain Kluyveromyces marxianus at 42 °C. Combination of 9 FPU g −1 substrate and CC plus 30 CBU of commercial β-glucosidase (Cβ) yielded slightly higher theoretical ethanol yields of 92.24 % as compared to 86.54 % obtained from IC+Cβ. Dunnett’s Post Hoc Annova test also proved that CC+Cβ were found to be significant in batch as well fed batch experiments as compared to other combinations tried. Thus, fed batch A-III seems to be an optimistic one to overcome the problems associated with batch mode to achieve higher ethanol yields.

Beschreibung: In the present work, ground granulated blast furnace slag (GGBS) and sewage sludge ash (SSA) blends were assessed for the production of alkali-activated pastes and mortars. Percentages of SSA to substitute GGBS ranged from 0 to 30 wt% and sodium concentrations of 6–10 mol kg −1 were used for the activating solutions. Pastes and mortars were cured at 20 °C for up to 90 days. Raw materials were characterised by granulometric analysis, XRF, XRD, FTIR and SEM techniques. The replacement percentage of GGBS by SSA and the sodium hydroxide concentration of the alkaline activator were optimised to produce mortar with compressive strengths close to 30 MPa after 28 curing days at room temperature. Best results were obtained in samples blended with 20 wt% SSA activated with 6 mol kg −1 NaOH solutions which, according to the XRD, FTIR and microscopic results, contained higher amounts of (N,C)–A–S–H gel. The potential use of SSA for the development of alternative cementitious materials at room temperature has been demonstrated.

Beschreibung: Sorption experiments for copper removal were carried out using two different parts of the brown seaweed Lessonia nigrescens ( L. nigrescens ) as biosorbent. The effect of initial pH, contact time, mass–volume-ratio (M/V) and initial metal concentration was evaluated. The best adsorption capacities were obtained at pH = 3.2 ± 0.2, and to reach equilibrium, 7 days of contact time were necessary for both sections of the seaweed. The maximum experimental uptake achieved was 54.5 mg Cu g −1 by the blades of the alga and 58.5 mg Cu g −1 by the stipes. Both Langmuir and Freundlich models described the equilibrium sorption isotherms very well when using stipes as biosorbent, but the fitting was poor with both models when blades were used as biosorbent. The Ho and McKay pseudo-second order model described the sorption kinetics for stipes and blades satisfactorily.

Beschreibung: Purpose This study investigated the chemical characteristics and anaerobic digestion of Chlorella sp. microalgae cultivated on various anaerobic digestion effluents (ADEs) as a nutrient medium. Chlorella sp. was grown in anaerobically digested effluent of dairy wastewater (DW), municipal wastewater sludge (WS), maize silage and swine slurry, and cattle manure (CM). Methods To evaluate the anaerobic biodegradability of harvested biomass, 20-days batch anaerobic digestion experiments were used. Results It was found that a nutrient medium directly affected nitrogen concentration in the cultivated biomass, as well as the C/N ratio value which ranged 7.2–12.9. Higher C/N ratio of the Chlorella sp. cultivated on DW and WS significantly enhanced the methane production, which was 241 ± 5.5 mL CH 4 /g VS and 267 ± 10.9 mL CH 4 /g VS, respectively. The highest biogas production rate of 61.28 ± 2.7 mL/g VS·d and methane concentration in biogas of 69.7 ± 4.1 % were obtained during the digestion of Chlorella sp. biomass cultivated on WS. Conclusions These results proved the applicability of ADEs as a nutrient medium for Chlorella sp. cultivation and the impact of a nutrient source on C/N ratio in harvested biomass, which subsequently affected the biogas/methane yield.

Beschreibung: The catalyzed conversion of waste cooking oil by transesterification into biodiesel yields exceptional environmental benefits and is the focus of this study. Sodium methoxide (CH 3 ONa), an alkaline catalyst, was selected for transesterification. A hydrothermal pretreatment was first applied to heat the kitchen waste to 140–170 °C. The pretreated waste cooking oil was then extracted from kitchen waste after a set time for use as a reactant. The aim of this study was to discuss whether hydrothermal pretreatment affects biodiesel productivity of waste cooking oil by alkali catalyst. Transesterification was conducted following hydrothermal pretreatment. Transesterification conditions were obtained from results of single factor experiments at 60 °C for 80 min, 0.9 wt% sodium methoxide concentration and 5:1 methanol/oil molar ratio. Maximum transesterification productivity reached 80.9 % locating the maximum increment of biodiesel productivity at 2.88 wt% relative to the control obtained under hydrothermal conditions at 160 °C for 80 min and a 1:1 volume ratio of kitchen waste to water. Biodiesel productivity was not impacted by hydrothermal temperature or hydrothermal time and analysis indicates principal properties of the final product complied with the European EN14214 Standard.

Beschreibung: Hazelnut shells are lignocellulosic by-products of hazelnut processing. As the shells are rich in cellulose and hemicellulose, they have high potential as a raw material for production of food enzymes, biofuel, and various chemicals (acetic acid, furfural and lignin degradation products) after bioprocessing. The objective of this study was to determine the effect of alkali pretreatment and enzymatic hydrolysis on production of fermentable sugars from hazelnut shells. The hazelnut shells were pretreated with sodium hydroxide (NaOH) at concentrations of 3–7 % (w/v) for 30–90 min at 121  ° C. Pretreatments were evaluated measuring delignification, solid recovery and production of reducing sugars after enzymatic hydrolysis of the pretreated biomass. Up to 20 % lignin removal was achieved and the highest reducing sugar yield of 318.3 mg/g pretreated biomass (or 91.7 % enzyme conversion efficiency) was obtained from biomass pretreated with 3 % NaOH at a solid to liquid ratio of 1:20 for 60 min. The response surface model predicted the optimal reducing sugar production (357.2 mg/g pretreated biomass) under 3 % NaOH, 1:13 of solid to liquid ratio and 63 min of pretreatment period at 121 °C. Overall, the results of this study show a promise for hazelnut shells to be used in production of value-added products.

Beschreibung: The sophorolipids are biosurfactants composed by a disaccharide sophorose linked by a hydroxyl group of a fatty acid. Due to their surface-active properties, sophorolipids have a great potential for using in different industrial sectors. They are synthesized by various strains of the genus Candida in the presence of hydrophilic and hydrophobic sources. In this study, it was evaluated the production of sophorolipids by Candida bombicola ATCC 22214 using sugar cane molasses, sugar cane juice, sucrose or glucose as hydrophilic source and chicken fat or sunflower oil as hydrophobic source. The sophorolipids were characterized and applied in bioremediation of soils contaminated with lubricating oil. The production of sophorolipids was 39.81 g L −1 in the optimized condition of 75 g L −1 of chicken fat, 77.5 g L −1 of glucose, 2.5 g L −1 of yeast extract and without urea. The sophorolipids produced present the diacetylated lactonic form, exhibiting the surface tension properties of 35 mN/m and of CMC 65 mg L −1 . The sophorolipids showed great emulsification index in lubricant oil, toluene and n-heptane, suggesting the potential application in bioremediation of lubricating-oil-contaminated soils. Graphical Abstract

Beschreibung: Agro-industrial residues have great potential as low-cost feedstocks for production of hydrolytic enzymes, which play a key role in the economics of cellulosic ethanol production. The goal of this research was to add value to agro-industrial byproducts such as wheat bran (WB), soybean bran, and sugarcane bagasse [either untreated (SCB) or pretreated (SCB p )] by using these materials for on-site production of enzymes employing a non-conventional solid-state and submerged fermentation method. The results were compared to conventional submerged fermentation, and three enzymatic cocktails were selected for use in SCB p hydrolysis. The non-conventional method was successfully validated for enzyme production using all the feedstocks. Compositional analysis and FTIR spectra showed the advantages of using WB, rather than SCB, due to its lower C:N ratio and lower contents of lignin and phenolic derivatives. The use of a WB:SCB mixture resulted in endoglucanase production that was up to 91 % higher than achieved using SCB alone. The best hydrolysis performance was achieved with the WB enzymatic cocktail, and the mixture of WB:SCB p resulted in cocktails with performance 51 % higher than cocktails produced with SCB p alone. The non-conventional on-site enzyme production using agro-industrial byproducts could potentially contribute to the implementation of large-scale 2G ethanol plants.

Beschreibung: Switchgrass-based, lignin-rich residues from cellulosic ethanol production were valorized into green chemicals via sequential methanol fractionation and hydrogenolysis depolymerization. The biomass residues were relatively purified by removing some structural carbohydrates and water soluble compounds. Methanol fractionation solubilized 14 % lignin from the above purified biomass residue, of which 95 % was klason lignin. The subsequent hydrogenolysis was catalyzed by Raney nickel with formic acid as hydrogen donors. Methanol soluble lignin fraction gave 58.11 % bio-oil yield, which was more than five times that from other fractions. The oxidation using hydrogen peroxide altered functional groups in lignin fractions but did not enhance the bio-oil yields. The GC–MS results revealed that bio-oil from all fractions except methanol soluble fraction contained more guaiacyl derivatives than syringyl derivatives. Sugar derivatives were generated at significant amounts from the depolymerization of the fractions that contained structural carbohydrates. Most of the generated monomers are renewable chemicals with wide industrial applications.

Beschreibung: Wastewater sludges were dried in an open greenhouse pilot in order to provide experimental data about solar greenhouse drying under an arid climate during hot and cold periods. Climatic conditions, solids contents and geometric dimensions were constantly measured. The shape change of samples was constantly recorded with digital scan. The results indicated that solar greenhouse drying reduced the moisture content from about 4 kg water/kg DS to 0.08 kg water/kg DS in hot period and to 0.2 kg water/kg DS in cold period in only 72 h. The higher values of drying rate were obtained in hot season. The maximum ranges obtained were 0.2 kg water/kg DS.h and 0.13 kg water/kg DS.h in hot and cold campaigns, respectively. Furthermore, a large volume reduction representing at least 80 % of initial volume was observed in both periods after 72 h of drying process. Also, shrinkage and cracks phenomena took place inside sludges. An improvement of the microbial condition of treated sludges was noted in hot campaign with a decrease by one order of magnitude after only 24 h for total and fecal coliforms and after 72 h for Clostridium perfringens, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus contents. These pathogenic bacteria were almost constant for fresh and dry sludges in cold period. The paper recommends the solar drying in hot as in cold periods under arid climate considering its average drying rate outside the rainy periods.

Beschreibung: This study examined the potential bio-oil production from the smouldering combustion of faeces mixed with sand, through a series of experiments. Surrogate faeces, with demonstrated equivalence to human faeces, were used in order to minimize variability in the composition. The yield of bio-oil was studied as a function of the following experimental parameters: original moisture content of the faeces, airflow rate and sand-to-faeces mass ratio. The amount of bio-oil collected was shown to be dependent on the airflow rate and the relative amount of sand used but independent on the moisture content. The bio-oil obtained was characterized by ultimate analysis, water content and calorific value. Under the experimental conditions studied, up to 70 g of bio-oil per kg of dry faeces (HHV = 27.6 kJ/g) can be produced. Finally, experiments demonstrated that sand can be reused after each experiment. The effect of the ash accumulation in the sand matrix on smouldering was investigated over five successive tests with the same batch of sand. The implementation of this technology to other type of organic waste would contribute to the development of an integrated waste treatment technology, in combination with bio-oil production.

Beschreibung: The objective of this work was to compare the effects of dilute acid hydrolysis on two major residues of rice crop cultivation, namely, rice straw and rice husk and to find the optimum hydrolysis parameters for both residues. The hydrolysis conditions were expressed by a severity factor (SF) in the range of −0.2 to 2.01. The xylose release reached maximum at SF of 1.96 for rice straw and 1.88 for rice husk hydrolysates. The glucose release and by-products productions were higher in the rice straw hydrolysate than rice husk hydrolysate over the entire range of SF. Response surface methodology was used for the optimization of the hydrolysis process. The optimum reaction temperature, reaction time, and acid concentration were 122 °C, 60 min and 2.95 % of acid concentration, respectively, for rice straw; the corresponding values for rice husk were 127 °C, 60 min and 2.6 % of acid concentration. Under these conditions, 88.1 % of xylose yield and 1.98 g/g of selectivity for rice straw and 87.7 % of xylose yield and 11.8 g/g of selectivity for rice husk were achieved.

Beschreibung: Amongst the many forms of food waste, bread is a major contributor to the problem. Two aims of this research investigate waste breads potential of being a bioresource for the production of fermentable sugars which are precursor of valuable bioproducts by fermentation process: finding optimum substrate, water and enzyme ratio to produce the highest amount of fermentable sugars and investigating the rheological behavior of the system during hydrolysis. Two stage waste bread hydrolysis was performed with enzymes α-amylase and amyloglucosiades and response surface methodology was used to optimize substrate, water and enzyme ratio. Discovery Hybrid Rheometer-2 (TA Instruments) fitted with a parallel-plate geometry was used to investigate steady flow viscosity of the slurry during hydrolysis. 99 % of theoretical maximum glucose yield, a main fermentable sugar, is achieved by optimizing enzymatic hydrolysis conditions of waste bread at liquefaction and saccharification stages. Just after the addition of α-amylase enzyme, substantial decrease is observed in viscosity and Casson apparent yield stress of the slurry. During saccharification stage, glucose yield increases dramatically while viscosity of the slurries is very low and does not change considerably. The results imply that utilizing high concentrations of waste bread as a feedstock to produce fermentation products offers economic benefits without causing high power consumption, excessive wear on equipment, and reduced conversion which are generally expected consequences for high-solid processing.

Beschreibung: Chitosan, an important biopolymer with many uses, is made by deacetylation of chitin. Classical hydrolysis at high temperatures (above 100 °C) in 50 % concentrated sodium hydroxide during several hours produces chitosan, a poly-beta-glucosamine. This chemical deacetylation step is often performed under pressure in boiling ethyleneglycol and tends to degrade polymer chain length, thus the interesting polymer properties. It is convenient to search for a more economical production pathway in order to make chitosan available for environmental applications, such as use in water suspended matter flocculation. Chitin was extracted from the exoskeletons of shrimps and its deacetylation kinetics was followed for 35 days at 20 and 35 °C. The results obtained using different techniques (conductivity, viscometry, 13 C NMR and thermogravimetry) showed that the deacetylation degree of chitin increased with the incubation time reaching 99 and 88 % at 35 and 20 °C, respectively, after 35 days. Moreover, during the incubation time, the molecular weight of chitosan showed moderate decrease compared to deacetylated chitin at high temperature. Clarification or urban waste water with chitosan biopolymer demonstrated good results at 1.5 mg/L concentrations.

Beschreibung: Feedstock supply challenges provide impetus into the exploration of lignocellulosic mixtures in bioprocessing. Such mixtures have not been fully explored for bacterial cellulase production. Four bacterial species were evaluated for ability to utilize a mixture of oil palm and rice residues (MS) for cellulase production. Bacillus aerius , Bacillus anthracis , Cellvibrio japonicus and Klebsiella pneumoniae with ability to utilize MS for growth were investigated. A two-step sequential strategy was employed in selecting the candidate for cellulase production and degradation of MS. B. aerius displayed better cellulolytic ability than the others during plate screening on carboxymethyl cellulose-enriched medium. However, C. japonicus produced the highest activities of endoglucanase and total cellulase during targeted screening on MS. Analyses revealed that sequential pretreatment with NaOH and moist heat increased the accessibility and disrupted the surface morphology of MS for subsequent bacterial utilisation. C. japonicus achieved significant degradation of MS with 52.33 % substrate dry weight loss after 7 days as compared to B. aerius which degraded 21.33 % of MS in the same period. Substrate was hydrolyzed via the amorphous region. The low residual concentration of reducing sugars in the medium suggested that C. japonicus converted the liberated sugars into other products.

Beschreibung: The recycling of multilayer packaging is hindered by the problematic separation of the packaging components. Among the numerous multilayer packaging, the ubiquitous 5-layer polyethylene/cardboard/polyethylene/aluminum/polyethylene one is one of the most difficult to recycle. This work examines how the synthetic polymer, cellulose and aluminum components can first be efficiently separated and secondly, how the recovered cellulose and polyethylene can be mixed to produce value-added composites. Size reduction and hydro-mechanical treatment of the packaging enabled the separation of cellulose from the PE and dual PE/aluminum layer. The delamination of the PE from the aluminum required a chemical treatment in an organic acid followed by separation by flotation/sedimentation. Instead of reusing the cellulose directly into a composite, the fibers were fractionated in order to produce fermentable sugars for a bio-refining operation and to recover value-added side-products known as microcrystalline cellulose (MCC). Thus, through the reaction with concentrated sulfuric acid, the recovered cellulose was decrystallized and partially hydrolyzed. It was then precipitated in a non-protic polar anti-solvent, and hydrolyzed in dilute sulfuric acid solution to generate MCC. This MCC was incorporated at levels up to 50 wt% into the recovered polyethylene using a twin-screw extrusion mixing process and then injection-molded. The elastic modulus and tensile strength increased linearly with the MCC content. A polyethylene grafted with maleic anhydride was added as a coupling agent between MCC and polyethylene during the compounding stage to further improve the composite properties. The composites were more homogeneous and the modulus and tensile strength were increased by around 20 % in presence of the coupling agent. Micrographs on rupture surfaces corroborated the improvement of cellulose wettability and interfacial adhesion in presence of the coupling agent. Graphical Abstract

Beschreibung: Refuse derived fuel (RDF) was processed using hydrothermal gasification at high temperature to obtain a high energy content fuel gas. Supercritical water gasification of RDF was conducted at a temperature of 500 °C and 29 MPa pressure and also in the presence of a solid RuO 2 /γ-Al 2 O 3 catalyst. The effect of residence time (0, 30 and 60 min) and different ruthenium loadings (5, 10, 20 wt% RuO 2 /γ-Al 2 O 3 ) were investigated. Up to 93 % carbon gasification efficiency was achieved in the presence of 20 wt% RuO 2 /γ-Al 2 O 3 catalyst. The fuel gas with the highest energy value of 22.5 MJ Nm −3 was produced with the 5 wt% RuO 2 /γ-Al 2 O 3 catalyst after 30 min reaction time. The results were compared with the use of NaOH as a homogeneous catalyst. When NaOH was used, the maximum gross calorific value of the product gas was 32.4 MJ Nm −3 at 60 min reaction time as a result of CO 2 fixation. High yields of H 2 and CH 4 were obtained in the presence of both the NaOH and RuO 2 /γ-Al 2 O 3 catalysts. Graphical Abstract

Beschreibung: In this study, co-pyrolysis of rice husk with underutilized biomass, Napier grass and sago waste was carried out in a fixed bed reactor at 600 °C, 30 °C/min and 5 L/min nitrogen flowrate. Two-phase bio-oil (organic and aqueous) was collected and characterized using standard analytical techniques. 34.13–45.55 wt% total boil-oil yield was recorded using assorted biomass compared to pure risk husk biomass with 31.51 wt% yield. The organic phase consist mainly benzene derivatives with higher proportion in the oil from the co-pyrolysis process relative to the organic phase from the pyrolysis of the individual biomass while the aqueous phase in all cases was predominantly water, acids, ketones, aldehydes, sugars and traces of phenolics. This study has demonstrated a good approach towards increasing valorization of rice husk in a single reaction step for the production of high grade bio-oil, which can be transformed into fuel and valuable chemicals.

Beschreibung: Degradation of aflatoxin B 1 in groundnut cake, a residue after oil extraction, by Rhodococcus erythropolis was optimized using response surface methodology. The bacterium was first grown in synthetic medium to determine optimal growth conditions using the combination of the Plackett – Burman and Box–Behnken methods and consequently aflatoxin B 1 in groundnut cake slurry was degraded under varying culture conditions. Optimal growth conditions were found as 22.5 °C of temperature, pH 7, 100 mL of culture volume in 500 mL flasks, 1 % (v/v) of inoculum size, 135 rpm of agitation speed, 5 g/L of glucose and 5 g/L of peptone concentration according to analysis of the Box–Behnken design. Optimal detoxification conditions were found as 27.4 % (w/v) of solid concentration, 4.88 % (v/v) of inoculum size and 24 h of incubation time by Box–Behnken response surface optimization. Maximum detoxification level was predicted as 92.2 % by the constructed model while the experimental counterpart was 87.3 %. The suggested culture conditions have the potential to decrease aflatoxin B 1 from 200 μg/kg to below 20 μg/kg, the regulatory limit, in feed materials. Further studies are needed to test the obtained results at a larger scale and to finalize safety assessment of the final product by animal testing. Graphical Abstract

Beschreibung: Purpose The aim of the study was to apply and optimize the process of bioconversion of pig bristle waste using keratinolytic enzymes of Bacillus cereus PCM 2849, and to evaluate the amino acid composition of the resultant hydrolysate. Methods Hydrolysis with concentrated culture fluid of B. cereus was applied for bioconversion of pig bristles, after thermo-chemical pretreatment with sulfite. The effect of substrate concentration, sulfite concentration during pretreatment and reaction temperature on the release of amino acids was determined using Box-Behnken design. Amino acid composition of the obtained hydrolysate was determined by HPLC. Structural condition and substructural changes of the residual substrate were evaluated with SEM microscopy and FTIR spectroscopy. Results The applied enzymatic preparation for bristle biodegradation was verified to contain multiple proteases of a wide molecular weight range. A regression model was developed, in which influential parameters were: linear effect of substrate concentration, followed by quadratic effects of reaction temperature, substrate concentration and pretreatment. Optimum reaction conditions were also determined. The resultant hydrolysate was rich in branched-chain amino acids. Residual substrate was detriorated and sulfitolytic cleavage of disulfides and alteration of protein secondary structures was confirmed. Conclusions Application of B. cereus crude keratinase allowed for partial hydrolysis of pig bristles, preceded by sulfitolytic pretreatment. A regression model was built to describe the process of hydrolysis to release free amino acids, at constant enzyme load. Hydrolysis in given conditions allowed to obtain hydrolysate rich in branched chain amino acids. The presented process poses an alternate way of management over pig bristles, a hard-to-degrade keratinous waste.

Beschreibung: Microalgae are nowadays regarded as a potential biomass feedstock to help reducing our dependence on fossil fuels for transportation, electricity and heat generation. Besides, microalgae have been widely investigated as a source of chemicals, cosmetics and health products, as well as animal and human feed. Among the cutting-edge applications of microalgae biomass, anaerobic digestion has shown promising results in terms of (bio)methane production. The interest of this process lies on its potential integration within the microalgae biorefinery concept, providing on the one hand a source of bioenergy, and on the other hand nutrients (nitrogen, phosphorus and CO 2 ) and water for microalgae cultivation. This article reports the main findings in the field, highlighting the options to increase the (bio)methane production of microalgae (i.e. pretreatment and co-digestion) and bottlenecks of the technology. Finally, energy, economic and environmental aspects are considered.

Beschreibung: Capia pepper seeds are the mass waste of pepper utilization, and they have not commonly utilized as raw materials. In this study, the defatted press cakes (or meals) of cold oil pressed capia pepper seeds were evaluated. The pepper seeds were previously roasted and treated with enzymes (hemicellulase and protease) against control, before pressing. The compositional and functional properties of the defatted meals were determined. Moisture, protein, remaining oil, ash, L , a *, b * values and viscosity of the meals were measured by basic physicochemical analyses. Phytic acid, tannins and mineral contents were also determined. As functional properties, water-holding capacity, oil-holding capacity, emulsion activity, emulsion stability, foaming capacity, foam stability and the least gelation concentration were measured. The meals were shown to contain nutritionally important amounts of protein and minerals. For most functional properties, seed roasting caused some enhancements in the meals. Hence, defatted capia pepper seed meals can be utilized in food formulations due to their good nutritional and functional properties. This study points out the possibility and advantages of pepper seed meal valorization. Graphical Abstract (1) Capia pepper seed press cakes (meals) were used in this study. (2) Functional and physicochemical properties of the meals were measured. (3) The meals included good levels of proteins and some minerals. (4) The meals had functionalities for water and oil holding, emulsification and foaming. (5) The meals could be used in food formulations for enhanced functionalities.

Beschreibung: This paper criticizes the effectiveness of carbonization as a thermal method to upgrade the fuel properties of refuse derived fuel (RDF). For this purpose, RDF was subjected to carbonization at temperatures between 400 and 900 °C to monitor the changes in organic and inorganic portions of RDF, and its burning characteristics. The obtained biochars were characterized by proximate and ultimate analyses, Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, and thermal analysis (TG, DSC) methods. It can be concluded that carbonization is able to improve the calorific value of RDF only when this process is applied at 400 °C since serious losses took place in organic part at higher temperatures and increase in the ash yield overtook the improvement in the fixed carbon content. Besides, carbonization led to important reductions in the burning reactivity and the obtained biochars showed more reasonable burning characteristics in comparison to untreated RDF.

Beschreibung: Dissolved organic matter (DOM) collected from a garage-type dry fermentation system was investigated using UV–Vis absorption and fluorescence spectroscopy. Spectral parameters A 253/203 , biological index and fluorescence index were used to assess the structural characteristics and sources of effluent DOM. The results showed that aromatic rings highly substituted with hydroxyl, carbonyl, ester and carboxylic groups were obtained in the aerobic decomposition stage, and microbially derived organic matter dominated in the dry anaerobic digestion process, suggesting that the hydrolysis of organic macromolecules (lignin) in the aerobic decomposition resulted in the formation of water-soluble intermediates which can be easily assimilated and metabolized by microbial cells in dry anaerobic digestion process. PARAFAC of the excitation–emission matrix spectra revealed five fluorescent components occurring in effluent DOM: four humic-like components (C1–C4) and one protein-like component (C5). The F max values of components 1, 2, 3 and 5 showed large fluctuation than that of component C4, suggested the formation and degradation of these components. Component C4, with high aromatic content and higher degree of humification, was more difficult to be utilized and degraded by microorganisms than other components. The PARAFAC–PCA displayed three PCA factors (factors 1, 2 and 3), which accounted for 34.51, 34.20 and 31.11 %, respectively, of the variance in fluorescent components. Humic-like component C4 showed positive factor 1 loadings. Factor 2 was mainly explained by the tryptophan-like component C5. The humic-like components 1, 2 and 3 concurrently showed a relatively high factor 3 loading. The PARAFAC–PCA in this study could separate the characteristics of the DOM fluorescent component namely the source strength of the humic-like components versus the contributions of protein-like components in the total fluorescence analyses.

Beschreibung: The energy demand is increasing dramatically during last years. Due to this, biomass has been considered as an interesting alternative for renewable energy production. The objective of this work was to evaluate the production of bioethanol, biogas and electricity for using plantain pseudostem and rice husk produced as agricultural wastes in Colombia through a biorefinery scheme. The chemical characterization of these residues was carried out to get the input data for the conceptual design of fermentation, anaerobic digestion and combustion processes. Finally a techno-economic evaluation was developed to compare the potential of each process. The rice husk biorefinery showed higher yields of biogas and electricity compared to the plantain pseudostem case. In general terms, it was observed that production costs of bioethanol (0.48 USD/kg against 0.82 USD/kg), biogas (0.27 USD/m 3 against 0.56 USD/m 3 ) and electricity (0.02 USD/kW against 0.03 USD/kW) were kept lower under a biorefinery approach compared to the stand-alone processes for the rice husk case. For plantain case all the results were negative both for stand alone and biorefinery cases. This work concluded that it is possible to take advantage of some agricultural wastes generated in Colombia under biorefinery scheme to produce bioethanol, biogas and electricity as source of energy to supply a fraction of the energetic demand in this country. Graphical Abstract

Beschreibung: Laccase production requires a cost effective boost from host organisms to meet the needs for its numerous applications. Addition of 1.2 g L −1 lignin to media culture of Trametes versicolor improved laccase production up to 1213.93 U L −1 , which was 3.69-fold higher in comparison with that without lignin addition. The laccase production of 1009.49 U L −1 was achieved using the lignin-contained hydrolysate from steam-exploded corn stalk in practice. Elucidated mechanism of lignin-stimulated laccase production showed increased production of reactive oxygen species and the copy number of the laccase gene transcript in the treated mycelia. Together these results provide insight into some of the intrinsic metabolic processes involved in the up-regulation of laccase production in the presence of lignin. It also provides a low-cost strategy for the enzyme production from wastes and renewable biomass.

Beschreibung: A series of hydroxylated mesoporous aluminum–boron catalysts with different Al/B molar ratios were synthesized through a sol–gel method, and were characterized by XRD, FT-IR, NH 3 -TPD, SEM and N 2 adsorption–desorption techniques. It was demonstrated that hydroxylated Al 2 B 3 containing more Lewis acidity showed superior activity to the other Al – B catalysts in dehydration of glucose to 5-hydroxymethylfurfural (HMF) with a high yield of up to 39.9 % and glucose conversion of 92.1 % at 140 °C for 2 h. The synergistic effect of Lewis and Bronsted acid sites in Al 2 B 3 catalyst was demonstrated to be crucial for efficient conversion of glucose to HMF.

Beschreibung: The vegetable oil industry generates several materials after oil extraction that can be used as animal feed but that can represent an environmental and public health concern in case of improper disposal. However, the bioconversion of these feedstocks for the production of enzymes of industrial interest, such as lipases, by fermentation is an interesting alternative to obtain a product of high added value from a low cost material. This study aimed to use canola cake and soybean meal as feedstocks for lipase production through solid-state fermentation by Yarrowia lipolytica. The lipase obtained from canola cake, after 28 h fermentation presented the highest activity of 72.6 ± 2.4 U/g when using olive oil as substrate. On the other hand, the activity of the lipase obtained from soybean meal, after 14 h of fermentation reached the highest value of 93.9 ± 2.9 U/g using olive oil as substrate. The lipase produced from canola cake presented optimal performance at alkaline pH and high temperatures, while the lipase extract produced from soybean meal presented better hydrolytic activity under mild conditions. Yarrowia lipolytica demonstrated high biotechnological potential for solid-state fermentation using canola cake and soybean meal, since it was able to produce lipase in both feedstocks in a short period of time, adding value to these agro-industrial co-products. Furthermore, the lipase crude extracts produced are versatile biocatalysts, once they presented significant hydrolytic activity in different conditions of temperature and pH.

Beschreibung: The poultry industry generates huge amounts of feather waste, which needs appropriate management to avoid environmental harm. Keratinolytic potential of Chryseobacterium sp. kr6 and Bacillus sp. kr16 was exploited for feathers bioconversion to produce protein hydrolysates. Increasing feather concentrations (10, 20, or 50 g/L) had minor effects on feather degradation by strain kr6, although the performance of strain kr16 was diminished as the feather concentration increased in culture media. At 50 g/L, strain kr6 degraded 75 % of the feathers after 96 h, and strain kr16 degraded 21 %. The feather-degrading efficiency of Chryseobacterium sp. kr6 was corroborated by a direct relationship between feather concentration and the content of released soluble protein and free amino acids, in comparison to Bacillus sp. kr16. In vitro analyses were performed to postulate feather hydrolysates as animal feed supplements. Digestibility of the hydrolysates was lower when compared to controls (soy protein and casein), but higher than feather meal (FM), which is a usual ingredient of animal feed. Methionine was the first limiting essential amino acid in the hydrolysates and FM; however, the protein digestibility-corrected amino acid scoring was higher for the hydrolysates. Predicted protein efficiency ratio and biological value of kr6 hydrolysates were higher than kr16 hydrolysates and FM. Hydrolysates produced through feathers bioprocessing could be considered as interesting protein-rich resources for animal feed, thus representing an alternative for the valorization of waste feathers.

Beschreibung: The use of thermogravimetric analysis to describe biomass kinetics often uses bench top thermogravimetric analyser (TGA) analysers which are only capable of low heating rates. The aim of this research was to compare experimental fast pyrolysis of Olive kernels in a bespoke laboratory thermogravimetric fluidised bed reactor (TGFBR) characterised by rapid heating rates at high flow rates, compared to a smaller bench scale fixed bed TGA system. The pyrolysis in the TGFBR was analysed by using the isothermal kinetic approach and it was theorised that the pyrolysis decomposition reactions occurred by two mechanisms depending on the temperature, resulting in an activation energy of 67.4 kJ/mol at temperatures below 〈500 °C and 60.8 kJ/mol at temperatures 〉500 °C. For comparison, a bench scale TGA was used to look at the thermal behaviour in different fixed bed thermal conditions giving a higher activation energy of 74.4 kJ/mol due to the effect of external particle gas diffusion. The effect of biomass particle size (0.3–4.0 mm) on the conversion of biomass at different temperatures, was investigated between 300 and 660 °C in the TGFBR. The results suggested inhibition of internal gas diffusion was more important at lower temperatures, but in comparison had no significant effect when measured in the fixed bed TGA at lower heating rates. Bench top TGA analysis of pyrolysis is a rapid and valuable method, but is limited by smaller sample sizes and lower heating rates. In comparison, the conditions encountered with the laboratory scale TGFBR are more likely to be relevant to larger scale systems where heat distribution, heat transfer and mass diffusion effects play major roles in the reactivity of biomass.