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  • Co-digestion of food waste and sewage sludge for methane production: Current status and perspective
    Bioresource Technol. (IF 5.807) Pub Date : 2018-04-10
    Sanjeet Mehariya, Anil Kumar Patel, Parthiba Karthikeyan Obulisamy, Elumalai Punniyakotti, Jonathan W.C. Wong

    Food waste (FW) is a valuable resource which requires sustainable management avenues to reduce the hazardous environmental impacts and add-value for better economy. Anaerobic digestion (AD) is still reliable, cost-effective technology for waste management. Conventional AD was originally designed for sewer sludge digestion, is not effective for FW due to mainly high organics and volatile fatty acid (VFA) accumulation, hence better technical aptitudes and biochemical inputs are required for optimal biogas production. Besides, to overcome these challenges, FW co-digestion with complementary organic waste e.g. sewage sludge (SS) mixed which complement each other for better process design. The main aim of this article is to summarize the recent updates and review different holistic approaches for efficient anaerobic co-digestion (AcoD) of FW and SS to provide a comprehensive review on the topic. Moreover, to demonstrate the status and perspectives of AcoD at present scenario for Hong Kong and rest of the world.

    更新日期:2018-07-21
  • Improving the lipid recovery from wet oleaginous microorganisms using different pretreatment techniques
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-20
    Md Shamim Howlader, Neeraj Rai, William Todd French

    Lipid extraction directly from the wet oleaginous microorganisms for biodiesel production is preferred as it reduces the energy input for traditional processes which require extensive drying of the biomass prior to the extraction. The high water content (≥80% on cell dry weight) in the wet biomass hinders the extraction efficiency due to the mass transfer limitation. This limitation can be overcome by pretreating wet biomass prior to the lipid extraction using pressurized gas that can be used alone or combined with other pretreatments to disrupt the cell wall. In this review, an extensive discussion on different pretreatments and the subsequent lipid extraction using these pretreatments is presented. Furthermore, a detailed account of the cell disruption using pressurized gas (e.g., CO2) treatment for microbial cell lysing is also presented. Finally, a new technique on lipid extraction directly from wet biomass using the combination of pressurized CO2 and microwave pretreatment is proposed.

    更新日期:2018-07-21
  • Mixed culture fermentation of synthesis gas in the microfiltration and ultrafiltration hollow-fiber membrane biofilm reactors
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-21
    Hua-Jie Wang, Kun Dai, Yun-Qi Wang, Hou-Feng Wang, Fang Zhang, Raymond Jianxiong Zeng

    The effects of pore sizes on the in-situ utilization of synthesis gas (syngas, H2 and CO) mixed culture fermentation (MCF) in the hollow-fiber membrane biofilm reactor (HfMBR) are not clear. Thus, the ultrafiltration (R1) and microfiltration (R2) HfMBRs were constructed. Syngas was totally consumed within the formed biofilm in R1; contrarily, it accumulated notably in R2. In the batch mode of R1 and R2, volatile fatty acids (VFAs) of acetate, butyrate and caproate were the main metabolites, but the production rate of total VFA in R1 (61.9 mmol-C/(L·d)) was higher than that of R2 (27.6 mmol-C/(L·d)). In the continuous mode, the R1 performance was much better than that of R2, and the biofilm in R2 was even washed out. Furthermore, Clostridium (30.0%) was the main genus in the enriched biofilm of R1, which converted syngas to VFAs. Thus, the ultrafiltration membrane shall be the suitable candidate for syngas MCF.

    更新日期:2018-07-21
  • Embedding photosynthetic biorefineries with circular economies: Exploring the waste recycling potential of Arthrospira sp. to produce high quality by-products
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-21
    Neha Sachdeva, Cyril Mascolo, Ruddy Wattiez, Baptiste Leroy

    This study was conducted with the aim of embedding circular economies (waste recycling) with photosynthetic biorefineries, for production of commercially viable by-products. Since nitrogen source constitute the major input costs for commercial Arthrospira sp. production, the use of nitrogen rich wastewater for Arthrospira sp. cultivation could significantly reduce their production costs. This study evaluated the effects of high concentrations (8.5-120 mM) of alternative nitrogen sources (urea, ammonium and nitrite) on the biochemical, pigment and proteomic profile of Arthrospira sp., under batch and continuous conditions. Arthrospira sp. cells fed with urea were quantified with modified biochemical and proteomic profile compared to the nitrate fed cells. No inhibitory effect of urea was observed on the biomass even at 120 mM. Nitrite fed cells exhibited comparable biochemical and proteomic profiles as nitrate fed cells. These results clearly indicated at the possibility of using urea rich wastewater streams for profitable cultivation of Arthrospira sp.

    更新日期:2018-07-21
  • Cultivation of an algae-bacteria consortium in wastewater from and industrial park: effect of environmental stress and nutrient deficiency on lipid production
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-21
    Frédérique Bélanger-Lépine, Alexandre Tremblay, Yannick Huot, Simon Barnabé

    Adoption of microalgae-sourced products depends on the economic feasibility. In the case of fatty acids, it is crucial to obtain high lipid yield, especially in the form of storage lipids (TAGs). However, the production of these lipids often comes into competition with the microalgae biomass, resulting in a decrease in growth. A microalgae culture integration project was conducted in an industrial park in Canada in order to cultivate microalgae from park’s wastewaters and then obtain products from the biomass. Different deficiencies and stresses were tested to evaluate what condition allowed the induction of the highest lipids accumulation without compromising the growth of microalgae. The results showed that the medium controlled to pH 7.0 allowed reaching the largest amount of extracted lipids (28 ± 4.3%). Companies involved in this project could be able to make significant savings by the reduced wastewater treatment costs and by not adding expensive nutrients in culture.

    更新日期:2018-07-21
  • Sludge reduction and microbial structures of aerobic, micro-aerobic and anaerobic side-stream reactor coupled membrane bioreactors
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-21
    Hongjian Pang, Zhen Zhou, Tianhao Niu, Lu-Man Jiang, Guang Chen, Biao Xu, Lingyan Jiang, Zhan Qiu

    An anoxic/oxic membrane bioreactor (MBR) and three side-stream reactor (SSR) coupled membrane bioreactors were operated in parallel to investigate effects of dissolved oxygen (DO) level in SSR on sludge reduction and microbial community structure of SSR-MBRs. The four MBRs were equally efficient in COD and ammonium nitrogen removal. The anaerobic and micro-aerobic SSR favored nitrogen removal through denitrification, simultaneous nitrification and denitrification and autochthonous substrate release as carbon source. The micro-aerobic SSR achieved greatly higher sludge reduction efficiency (61.1%) than anaerobic (37.3%) and aerobic SSR (7.9%). Micro-aerobic SSR obtained the highest endogenous decay constant (0.035 d-1) compared to anaerobic (0.023 d-1) and aerobic SSR (0.015 d-1). High-throughput sequencing results revealed that anaerobic SSR enriched hydrolytic and fermentative bacteria, aerobic environment favored the growth of slow-growing bacteria, and micro-aerobic SSR stimulated biological activities of both anaerobic and aerobic bacteria.

    更新日期:2018-07-21
  • Mitigating adverse impacts of varying sulfide/nitrate ratios on denitrifying sulfide removal process performance
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-21
    Chuan Chen, Bo Shao, Ruo-Chen Zhang, Xi-Jun Xu, Xu Zhou, Yuan Yuan, Nan-Qi Ren, Duu-Jong Lee

    Complete removal of nitrogen, sulfur and carbon in wastewaters by denitrifying sulfide removal (DSR) process can be achieved at stoichiometry sulfide to nitrate ratio (S/N) of 1:1 in expanded granular sludge bed reactor. Wastewaters with varying S/N ratios can adversely impact the DSR performances with deterioration of synergetic cooperation between autotrophic and heterotrophic denitrifiers. DO (dissolved oxygen) serves effectively as supplementary electron receiver for sulfide oxidation, leaving more nitrate for heterotrophic denitrifiers to utilize acetate. The optimal oxygen to sulfide molar ratio (DO/S) is 0.5:1 for complete removal of sulfide, nitrate and acetate at different S/N ratios. The heterotrophic denitrification rate was decreased to 0.03±0.002, 0.24±0.011 and 0.35±0.027 NO3--N•h-1•gVSS-1 at S/N ratio of 5:2, 5:5 and 5:8, respectively, when DO/S of 3:1 was performed. This optimal condition was proposed as an easy-to-implement control criterion for subsiding the adverse impact by varying S/N ratios in handling real wastewaters.

    更新日期:2018-07-21
  • A Novel Mechanistic Model for Nitrogen Removal in Algal-Bacterial Photo Sequencing Batch Reactors
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-19
    Lai Peng, H.H. Ngo, W.S. Guo, Y. Liu, D. Wang, S. Song, W. Wei, L.D. Nghiem, B.J. Ni

    A comprehensive mathematical model was constructed to evaluate the complex substrate and microbial interaction in algal-bacterial photo sequencing batch reactors (PSBR). The kinetics of metabolite, growth and endogenous respiration of ammonia oxidizing bacteria, nitrite oxidizing bacteria and heterotrophic bacteria were coupled to those of microalgae and then embedded into widely-used activated sludge model series. The impact of light intensity was considered for microalgae growth, while the effect of inorganic carbon was considered for each microorganism. The integrated model framework was assessed using experimental data from algal-bacterial consortia performing sidestream nitritation/denitritation. The validity of the model was further evaluated based on dataset from PSBR performing mainstream nitrification. The developed model could satisfactorily capture the dynamics of microbial populations and substrates under different operational conditions (i.e. feeding, carbon dosing and illuminating mode, light intensity, influent ammonium concentration), which might serve as a powerful tool for optimizing the novel algal-bacterial nitrogen removal processes.

    更新日期:2018-07-20
  • Montmorillonite supported Nanoscale Zero-valent Iron immobilized in Sodium alginate (SA/Mt-NZVI) Enhanced the Nitrogen Removal in Vertical Flow Constructed Wetlands (VFCWs)
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-19
    Yufeng Zhao, Xin Cao, Xinshan Song, Zhimiao Zhao, Yuhui Wang, Zhihao Si, Fanda Lin, Yan Chen, Yinjiang Zhang

    Lacking of electron donor generally causes the low denitrification performance of constructed wetlands (CWs). Montmorillonite supported nanoscale zero-valent iron immobilized in sodium alginate (SA/Mt-NZVI) as novel electron donor-acceptor compounds were added in the denitrification zone of vertical flow constructed wetlands (VFCWs) to enhance the nitrogen removal. The key factors of the SA/Mt-NZVI dosage, the hydraulic retention time (HRT) of VFCWs, and the C/N ratios of influent were explored. SA/Mt-NZVI significantly improved the nitrogen (NO3--N) removal efficiency in VFCWs. When the optimal dosage of SA/Mt-NZVI was set as 2 g and the C/N was set as 6, the highest NO3--N removal efficiency was improved by 32.5±1.0%. The microbial community analysis of by 16S rRNA had revealed that Proteobacteria and Bacteroidetes at phylum level and Betaproteobacteria, Gammaproteobacteria, and Alphaproteobacteria at class level played an important role in nitrogen removal.

    更新日期:2018-07-20
  • Nitrogen removal via nitritation pathway for low-strength ammonium wastewater by adsorption, biological desorption and denitrification
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-19
    Zhenguo Chen, Xiaojun Wang, Xiaozhen Chen, Jing Chen, Feng Xinghui, Xingxing Peng

    Stable nitritation for low-strength ammonium wastewater was the key obstacle for cost-effective and low-carbon biological nitrogen removal. A zeolite biological fixed bed (ZBFB) and an anoxic sequencing batch reactor (ASBR) were successfully applied for achieving nitritation-denitrification of low-strength ammonium wastewater by adsorption, biological desorption and denitrification. Based on free ammonia inhibition on biofilm, stable nitrite accumulation could be realized with suitable operational time and aeration in biological desorption. During cycle operation, adsorption effluent NH4+-N kept at 3.0-4.0 mg/L, biological desorption effluent NO2--N maintained at 226.8-243.2 mg/L with average nitrite accumulation ratio of 97.18%, and nitrite removal rate was about 0.628 to 0.672 kg NO2--N·m-3·day, revealing obvious feasibility of ZBFB and ASBR for low-strength ammonium wastewater treatment. High-throughput sequencing analysis results further presented significant microbial community variations happened after cycle operation, with ammonia oxidizing bacteria enrichment and nitrite oxidizing bacteria inhibition in ZBFB and dominance of denitrifiers in ASBR.

    更新日期:2018-07-20
  • Performance evaluation of gaseous emissions and Zn speciation during Zn-rich antibiotic manufacturing wastes and pig manure composting
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-19
    Junchao Zhao, Xining Sun, Mukesh Kumar Awasthi, Quan Wang, Xiuna Ren, Ronghua Li, Hongyu Chen, Meijing Wang, Tao Liu, Zengqiang Zhang

    In this study, the co-composting performance of Zn-rich antibiotic manufacturing wastes (AMW) and pig manure (PM) was evaluated. Four treatments, representing 2.5%, 5%, 10% and 20% of AMW (of PM dry weight) and control without AMW, were established during composting. Results suggested that the temperature, pH, electrical conductivity, NH4+-N and germination index in end product met the maturity and sanitation requirement. More than 99% of residual antibiotic was removed as compared with PM composting alone. The cumulative CH4 and N2O emissions in AMW composting increased by 13.46-79.00% and 10.78-65.12%, respectively. While the higher mixing ratios of AMW (10% and 20%) presented a negative impact on composing by inhibiting organic matter (OM) degradation and higher NH3 emissions. The AMW had highly bioavailable Zn, but the exchangeable faction of Zn significantly decreased with the composting progress.

    更新日期:2018-07-20
  • Calcium-rich biochar from crab shell: an unexpected super adsorbent for dye removal
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-19
    Lichun Dai, Wenkun Zhu, Li He, Furong Tan, Nengmin Zhu, Qin Zhou, Mingxiong He, Guoquan Hu

    Adsorption is the common-used method to remove dyes from wastewater, and many efforts have been made to develop low-cost but excellent adsorbents. Here, calcium-rich biochar (CRB) as a low-cost adsorbent was directly prepared from crab shell via a simple pyrolysis process without any modification. Batch adsorption results suggested that CRB was among the dye adsorbents with highest adsorption capacities and fastest adsorption rate. Specifically, it showed high adsorption capacities of 12502 and 20317 mg/g for cationic malachite green and anionic Congo red, respectively. The adsorption equilibrium for Congo red onto CRB could be achieved as short as 2 min. Furthermore, the dye adsorption mechanism for CRB, as investigated by zeta potential and FTIR spectra, could be attributed to electrostatic attraction, hydrogen bonding and π-π interaction. Finally, this study suggested that, attributed to its cheap source, simple synthesis process and excellent adsorption performance, CRB was promising in dye removal.

    更新日期:2018-07-20
  • Accelerating the start-up of the cathodic biofilm by adding acyl-homoserine lactone signaling molecules
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-19
    Yanlun Fang, Chengsheng Deng, Jing Chen, Jian Lü, Shanshan Chen, Shungui Zhou

    Electroactive biofilms (EABs) are essential for bioelectrochemical systems, however, the formation of cathodic EABs is more time-consuming than anodic EABs. This study aims to evaluate whether acyl-homoserine lactones (AHLs) could facilitate the start-up of cathodic Geobacter soli EABs. With AHL addition, the biomass, cell viability, and extracellular polymeric substance (EPS) abundance of cathode-associated G. soli EABs were increased. Likewise, redox activities of EPS and outermost proteins in the cathodic EABs were enhanced in the presence of AHLs, which concequently led to better start-up performance of biofilms. Compared to the control without AHLs, start-up lag periods were reduced by approximately 50%, electron uptakes were enhanced by 1.3 to 2.0 times, and denitrification rates were more than doubled with AHL addition in the start-up cycle, which were comparable to those of mature G. soli cathodic EABs. These findings open up an opportunity for accelerating the start-up of cathodic biofilms via AHLs.

    更新日期:2018-07-20
  • High oxygen reduction reaction performance nitrogen-doped biochar cathode: A strategy for comprehensive utilizing nitrogen and carbon in water hyacinth
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-19
    Jiaxiang Liang, Diyong Tang, Li Huang, Yifei Chen, Wei Ren, Jie Sun

    In this study, a novel nitrogen-doped biochar oxygen reduction reaction cathode-water hyacinth carbon, was prepared by ZnCl2 molten salt carbonization without additional nitrogen source, which displayed a high performance in electro-Fenton (E-Fenton) process. The BET result shows that water hyacinth carbon achieved a much larger specific surface area (829 m2·g-1) than non-melt salt carbonized one (323 m2·g-1) and graphite powder (28 m2·g-1). Furthermore, characterization by XPS and EIS shows that both pyridinic-N (43.24%) and graphitic-N (56.75%) existed in water hyacinth carbon and Warburg constant was only 0.051. Because of a high H2O2 producing yield 1.7 mmol·L−1 and corresponding current efficiency 81.2 ± 2.5% in molten salt carbonized water hyacinth biochar, a high kinetic constant 0.318 min-1 in DMP degradation was achieved, which was 4 times higher than graphite powder (0.076 min-1). The TOC removal achieved 86.8% in 30 min and the corresponding energy consumption reached a low level 60.15 kW·h·kgTOC-1.

    更新日期:2018-07-20
  • Optimization of sugarcane bagasse pretreatment using Alkaline Hydrogen Peroxide through ANN and ANFIS modelling
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-19
    Artur S.C. Rego, Isabelle C. Valim, Anna A.S. Vieira, Cecília Vilani, Brunno F. Santos

    The present study compares the optimization using Artificial Neural Networks (ANN) and Adaptive Network-based Fuzzy Inference System (ANFIS) in the sugarcane bagasse delignification process using Alkaline Hydrogen Peroxide (AHP). Two variables were assessed experimentally: temperature (25 – 45 °C) and hydrogen peroxide concentration (1.5 – 7.5 %(w/v)). The Klason Method was used to measure the amount of insoluble lignin, the High Performance Liquid Chromatography (HPLC) was used to determine the glucose and xylose concentrations and the Fourier Transform Infrared Spectroscopy (FT-IR) was applied to identify oxidized lignin structure in the samples. The analytical results were used for training and testing of ANN and ANFIS models. The statistical quality of the models was significant due to the low values of the errors indices (RMSE) and determination coefficient R2 between experimental and calculated values.

    更新日期:2018-07-20
  • Entrapped Biomass for Removal of Organics and Total Nitrogen from Anaerobic Reactor Effluents
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-19
    Haon-Yao Chen, Kok Kwang Ng, Chien-Hsien Lee, Tzu-Yang Chen, Pui-Kwan Andy Hong, Ping-Yi Yang, Cheng-Fang Lin

    Anaerobic processes have been applied to treat low-strength domestic wastewaters with significant energy saving. However, anaerobic process effluents must be further removed of residual organics and total nitrogen before discharge. Reported here are an aerobic entrapped bio-technology (EBT) system and an EBT coupled with activated sludge (EBT+AS) system being tested as a post-anaerobic treatment. Both systems have been operated under aerobic condition to provide organics and total nitrogen removal, achieving COD removal by 74-88% and TN removal by 58-65% at hydraulic retention times of 8-24 h. ΔCOD/ΔNO3 ratios that represent the carbon usage efficiency as electron donors for denitrification were 1.82-1.93 in the EBT and 2.01-2.02 in the EBT+AS systems, with both ratios being lower (i.e. more efficient) than 6 typically required in traditional activated sludge bioreactors. Both systems demonstrate promise for polishing removal of COD and TN.

    更新日期:2018-07-20
  • Succession of bacteria diversity in the poultry manure composted mixed with clay: Studies upon its dynamics and associations with physicochemical and gaseous parameters
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-19
    Mukesh Kumar Awasthi, Hongyu Chen, Quan Wang, Tao Liu, Yumin Duan, Sanjeev Kumar Awasthi, Xiuna Ren, Zhineng Tu, Jiao Li, Junchao Zhao, Zengqiang Zhang

    In this study, the bacterial community succession and variations were investigated in poultry manure(PM)compost by the using high-throughput sequencing in six different concentration of clay [at 0% (T1), 2%(T2), 4%(T3), 6%(T4), 8%(T5) and 10% (T6) on PM dry weight basis] applied compost. The results indicated that dominant phylum were Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes, while Bacillus, Paenibacillus, Virgibacillus, Oceanobacillus and Clostridium were the dominant genera in all the treatments. Correlation analyses provided useful tools for insight into the bacterial interactions with environmental factors and also extension of the compost maturation and resistance of bacteria. During the course of study, the diversity of bacteria similar but relative abundance variable in each treatments. However, the average and the normalized (to bacterial RAs or copies of sequences)both remained greater in higher dosage of clay applied treatments. Finally, the RAs of various bacterial community composition was affected in PM compost by the clay application.

    更新日期:2018-07-20
  • Intracellular carbonic anhydrase from Citrobacter freundii and its role in bio- sequestration
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-19
    Anand Giri, Uttam Chand Banerjee, Manoj Kumar, Deepak Pant

    The aim of this work was to study the CO2 bio-sequestration application of indigenous Citrobacter species and its carbonic anhydrase (CA). Intracellular CA was purified from Citrobacter freundii (CF; accession no: MH283871) isolated from limestone rock site in Kumaun region of Indian Himalaya studied for the sequestration of carbon dioxide and the formation of calcite. CF showed maximum CA enzyme activity at 11.3U/ml at pH 7.0 and 37°C. Hydration of CO2 into carbonate was characterized by calcite phase of calcium carbonate using absorption spectroscopy and imaging technique. Purified CA showed a significantly high CO2 sequestration capacity of 230mg CaCO3/mg of purified as compared to crude enzyme (50mg CaCO3/ml of enzyme).

    更新日期:2018-07-20
  • Economic and life-cycle greenhouse gas optimization of microalgae-to-biofuels chains
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-18
    Wei Wu, Keng-Hsien Lin, Jo-Shu Chang

    The new microalgae-to-biofuels chains for producing diesel and ethanol simultaneously are presented. The techno-economic analysis shows that the break-even prices of diesel and ethanol are estimated about US$0.49/kg and US$2.61/kg, respectively, the internal rate of return (IRR) is close to 29.21%, and the commercial prices and yield of products dominate the profitability of this project. According to life cycle analysis (LCA) standards, the life-cycle greenhouse gas (GHG) emissions for producing diesel and ethanol are 0.039 kg CO2-eq/MJ FAME and 0.112 kg CO2-eq/MJ EtOH, respectively. It is verified that the process integration of the heat recovery scheme, the entrainer recovery tower, and CO2 recycling can effectively reduce life-cycle GHG emissions of this design. Through a specific optimization algorithm under different lipid contents and 180 scenario combinations for the cultivation and pretreatment processes, the compromise solutions between the maximum total revenue and the minimum environmental impact can be found.

    更新日期:2018-07-18
  • Investigation of Representative Components of Flue Gas Used as Torrefaction Pretreatment Atmosphere and Its Effects on Fast Pyrolysis Behaviors
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-17
    Yinhai Su, Shuping Zhang, Lingqin Liu, Dan Xu, Yuanquan Xiong

    In this study, three torrefaction atmosphere (N2, CO2 and 2 vol.% O2 with N2 balance) were used to study effects of representative main components of flue gas during torrefaction and subsequent pyrolysis. Torrefaction pretreatment was carried out in a fixed-bed reactor at 230 °C and 250 °C, respectively. Results showed after torrefaction, torrefied samples from oxygenated atmosphere presented severer hemicellulose decomposition. And its effects on fast pyrolysis were investigated in thermogravimetry analysis and bench-scale fixed-bed reactor. It was found that oxygenated atmosphere preferred to give higher relative content of phenols at 230 °C and furans at 250 °C. For CO2, higher relative content of ketones and lowest phenols were got. The result also indicated that it's the O2 in flue gas which significantly improved the char yield. These results will be beneficial reference to predict and interpret alterations of pyrolysis behaviors when flue gas constitution changes in industrial application.

    更新日期:2018-07-18
  • Adaptive evolution of microalgae Schizochytrium sp. under high salinity stress to alleviate oxidative damage and improve lipid biosynthesis
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-17
    Xiao-Man Sun, Lu-Jing Ren, Zhi-Qian Bi, Xiao-Jun Ji, Quan-Yu Zhao, He Huang

    Lipid accumulation of Schizochytrium sp. can be induced by stress condition, but this stress-induction usually reduce cell growth and cause oxidative damage, which can eventually lower the lipid yield. Here, adaptive laboratory evolution (ALE) combined high salinity was performed to enhance the antioxidant system and lipid accumulation. The final strain ALE150, which was obtained after 150 days, showed a maximal cell dry weight (CDW) of 134.5g/L and lipid yield of 80.14g/L, representing a 32.7 and 53.31% increase over the starting strain, respectively. Moreover, ALE150 exhibited an overall higher total antioxidant capacity (T-AOC) and lower reactive oxygen species (ROS) levels than the starting strain. Furthermore, the regulatory mechanisms responsible for the improved performance of ALE150 were analyzed by transcriptomic analysis. Genes related to the antioxidant enzymes and central carbon metabolism were up-regulation. Moreover, the metabolic fluxes towards the fatty acid synthase (FAS) and polyketide synthase (PKS) pathways were also changed.

    更新日期:2018-07-18
  • Metabolic engineering of Escherichia coli for 1,3-propanediol biosynthesis from glycerol
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-17
    Bo Yang, Shaoxiong Liang, Huanhuan Liu, Jiao Liu, Zhenzhen Cui, Jianping Wen

    In this study, the engineered E. coli was constructed for efficient transformation of glycerol to 1,3-propanediol (1,3-PDO). To regenerate NADPH, the key bottleneck in 1,3-PDO production, heterologous NADP+-dependent glyceraldehyde-3-phosphate dehydrogenase (GAPDN, encoded by gapN) pathway was introduced, and the gapN expression level was fine-tuned with specific 5’-untranslated regions (5’-UTR) sequences to balance the carbon flux distribution between the metabolic pathways of NADPH regeneration and 1,3-PDO biosynthesis. Additionally, glucose was added to the medium to promote glycerol utilization and cell growth. To elevate the utilization of glycerol in the presence of glucose, E. coli JA11 was constructed through destroying PEP-dependent glucose transport system while strengthening the ATP-dependent transport system. Subsequent optimization of nitrogen sources further improved 1,3-PDO production. Finally, under the optimal fermentation condition, E. coli JA11 produced 13.47 g/L 1,3-PDO, with a yield of 0.64 mol/mol, increased by 325% and 100% compared with the original engineered E. coli JA03, respectively.

    更新日期:2018-07-18
  • Recent achievement in enhancing anaerobic digestion with carbon- based functional materials
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-17
    Jishi Zhang, Wenqian Zhao, Huiwen Zhang, Zejie Wang, Chuanfang Fan, Lihua Zang

    Carbon-based materials such as graphite, graphene, biochar, activated carbon, carbon cloth and nano-tube, and maghemite and magnetite carbons are capable for adsorbing chemicals onto their surfaces. Currently, this review is to highlight the relevance of carbons in enhancing hydrogen or methane production. Some key roles of carbons in improving cell growth, enrichment and activity, and accelerating their co-metabolisms were elaborated with regard to their effects on syntrophic communities, interspecies electron transfer, buffering capacity, biogas upgrading, and fertilizer nutrient retention and land application. Carbons can serve as a habitation for microbial immobilization, and a provision for bioelectrical connections among cells, and provide some essential elements for anaerobes. Besides, an outlook on the possible options towards the large scale and improvement solutions has been provided. Further studies in this area could be encouraged to intend and operate continuous mode by designing carbon-amended bioreactor with stability and reliability.

    更新日期:2018-07-18
  • Isolation of a novel strain of Monoraphidium sp. and characterization of its potential for α-linolenic acid and biodiesel production
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-17
    Yimeng Lin, Jingping Ge, Hongzhi Ling, Yunye Zhang, Xiufeng Yan, Wenxiang Ping

    α-Linolenic acid (ALA) is an essential fatty acid which cannot be synthesized de novo in mammals and must be ingested regularly in the diet. In this study, a microalgal strain named HDMA-11 was isolated from Lake Ming, China, and was found to accumulate a high ALA content (39.2% of total lipids). Phylogenetic neighbor-joining analysis indicated that HDMA-11 belongs to the genus Monoraphidium (Selenastraceae, Sphaeropleales) and its 18S ribosomal DNA sequence seemed to be a new molecular record of a Monoraphidium species. The fatty acid profiles, biomass productivity and lipid content of HDMA-11 were also investigated in autotrophic conditions. The high levels of polyunsaturated fatty acids in HDMA-11, especially ALA, make it suitable as a source of nutritional supplementation for human health. Furthermore, HDMA-11 exhibited good properties for biodiesel production, characterized by high lipid content (28.5% of dry weight), moderate biomass productivity (31.5 mg L−1 day−1) and a promising lipid profile.

    更新日期:2018-07-18
  • Microbial lipid production and organic matters removal from cellulosic ethanol wastewater through coupling Oleaginous yeasts and activated sludge biological method
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-17
    Xueling Zhang, Meng Liu, Xu Zhang, Tianwei Tan

    In this paper, a novel strategy for lipid production through coupling oleaginous yeasts and activated sludge biological methods by cultivation of Rhodotorula glutinis in cellulosic ethanol wastewater was studied. Under optimal conditions in wastewater medium (dilution ratio of 1:2 and glucose supplement of 40 g/L), the maximum biomass and lipid content as well as the lipid yield reached 11.31 g/L, 18.35% and 2.08 g/L, with the associated removal rates of COD, TOC, NH4+-N, TN and TP reaching 83.15%, 81.81%, 85.49%, 70.52% and 67.46%, respectively. Cellulosic ethanol wastewater treated by the anaerobic-aerobic biological process resulted in removal of COD, NH4+-N, TP and TN reaching 67.55%, 94.17%, 90.16% and 48.89%, respectively. The reused water was used to dilute medium of R. glutinis for microbial lipid production reaching 2.38 g/L and caused positive effects on the accumulation of biomass and lipid.

    更新日期:2018-07-18
  • Biological removal of pharmaceuticals from hospital wastewater in a pilot-scale staged moving bed biofilm reactor (MBBR) utilising nitrifying and denitrifying processes
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-17
    Gordon T.H. Ooi, Kai Tang, Ravi K. Chhetri, Kamilla M.S. Kaarsholm, Kim Sundmark, Caroline Kragelund, Klaus Litty, Alice Christensen, Sabine Lindholst, Christina Sund, Magnus Christensson, Kai Bester, Henrik R. Andersen

    Hospital wastewater contains high concentrations of pharmaceuticals, which pose risks to receiving waters. In this study, a pilot plant consisting of six MBBRs in series (with the intention to integrate BOD removal, nitrification and denitrification as well as prepolishing COD for ozonation) was built to integrate pharmaceutical removal and intermittent feeding of the latter reactors aimed for micropollutant removal. Based on the experiments, nitrifying MBBRs achieved higher removal as compared to denitrifying MBBRs except for azithromycin, clarithromycin, diatrizoic acid, propranolol and trimethoprim. In the batch experiment, nitrifying MBBRs showed the ability to remove most of the analysed pharmaceuticals, with degradation rate constants ranging from 5.0 × 10-3 h-1 to 2.6 h-1. In general, the highest degradation rate constants are from the nitrifying MBBRs while the latter MBBRs showed lower degradation rate constant. However, when the degradation rate constants were normalised to the respective biomass, the intermittently fed reactors presented the highest specific activity. Out of the 22 compounds studied, 17 compounds were removed with more than 20%.

    更新日期:2018-07-18
  • Bead milling disruption kinetics of microalgae: process modeling, optimization and application to biomolecules recovery from Chlorella sorokiniana
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-17
    Téné Rosine Zinkoné, Imma Gifuni, Laurence Lavenant, Jérémy Pruvost, Luc Marchal

    Industrial development of microalgae biomass valorization relies on process optimization and controlled scale-up. Both need robust modeling: (i) for biomass production and (ii) for integrated processes in the downstream processing (DSP). Cell disruption and primary fractionation are key steps in DSP. In this study, a kinetic model, including microalgal cell size distribution, was developed for Chlorella sorokiniana disruption in continuous bead milling. Glass beads of 0.4 mm size at impeller tip velocity of 14 m.s-1 were used as optimal conditions for efficient cell disruption. These conditions allowed faster disruption of big cells than small ones. A modified expression of the Stress Number, including cell size effect, was then proposed and validated. Separation of starch, proteins and chlorophyll by mild centrifugation was studied as function of the disruption parameters. Low energy consumption conditions led to extreme comminution. An intermediate zone drew attention for allowing moderate energy consumption and efficient metabolites separation by centrifugation.

    更新日期:2018-07-18
  • Application of ionic liquid and alkali pretreatment for enhancing saccharification of sunflower stalk biomass for potential biofuel-ethanol production
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-17
    Parushi Nargotra, Vishal Sharma, Mahak Gupta, Simranjeet Kour, Bijender Kumar Bajaj

    Biorefining of lignocellulosic biomass to fuels/chemicals has recently gained immense research momentum. Current study reports sequential pretreatment of sunflower stalk biomass in a combinatorial regime involving alkali (NaOH) and ionic liquid 1-butyl-3-methyl imidazolium chloride. The pretreatment enhanced the enzymatic digestibility, and resulted in increased sugar yield (163.42 mg/g biomass) as compared to standalone pretreatment using alkali (97.38 mg/g biomass) or ionic liquid (79.6 mg/g biomass). Ultrastructural and morphological analysis (FTIR and SEM) of pretreated biomass showed that the combined ionic liquid and alkali pretreatment causes more drastic alterations in the biomass ultrastructure as compared to alone ionic liquid or alkali pretreatment. Thus, combined pretreatment led to ease of enzymatic saccharification and consequent increased sugar yield, and this observation was corroborated by physicochemical analysis of the pretreated biomass. The pretreated SFS biomass was subjected to consolidated bioprocessing for its direct conversion to bioethanol in a single vessel.

    更新日期:2018-07-18
  • Influence of sugar beet pulp and paper waste as bulking agents on physical, chemical, and microbial properties during green waste composting
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-10
    Lu Zhang, Xiangyang Sun

    Composting is considered to be a natural, sustainable, and highly beneficial method for solid waste disposal. The objective of this study was to investigate the two-stage composting of green waste (GW) as affected by the addition of sugar beet pulp (SBP; at 0, 25, and 35%) and/or paper waste (PW; at 0, 5, and 10%) as bulking agents. The combination of SBP and PW greatly improved the composting conditions and the final compost quality in terms of composting temperature; pH; emissions of ammonia, nitrite nitrogen, and carbon dioxide; lignocellulose degradation; microbial abundance; enzyme activities; particle-size distribution; the ratio of water-soluble organic carbon to organic nitrogen; and phytotoxicity. The optimal two-stage composting process of GW and the highest quality compost product were obtained with the combination of 25% SBP and 10% PW. This optimal combination of bulking agents produced a mature and stable final compost product in only 20 days.

    更新日期:2018-07-12
  • Novel insights into scalability of biosurfactant combined microwave disintegration of sludge at alkali pH for achieving profitable bioenergy recovery and net profit
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-10
    J. Rajesh Banu, R. Yukesh Kannah, S. Kavitha, M. Gunasekaran, Gopalakrishnan Kumar

    In the present study, a novel alkali rhamnolipid combined microwave disintegration (ARMD) was employed to achieve net energy production, increased liquefaction and to increase the amenability of sludge towards biomethanation. Additionaly, biosurfactant rhamnolipid under alkali conditions enhances the liquefaction at alkali pH of 10 with a maximal liquefaction of 55 % with reduced energy consumption (1620 kJ/kg TS) than RMD (45.7 % and 3240 kJ/kg TS specific energy) and MD (33.7 % and 6480 kJ/kg TS specific energy). A higher biomethane production of 379 mL/g COD was achieved for ARMD when compared to RMD (329 mL/g COD) and MD (239 mL/g COD). The scalable studies imply that the ARMD demands input energy of -282.27 kWh. A net yield of (0.39 USD/ton) was probably achieved via novel ARMD technique indicating its suitability at large scale execution when compared to RMD (net cost -31.34 USD/ton) and MD (-84.23 net cost USD/ton), respectively.

    更新日期:2018-07-12
  • Effects of hydraulic retention time on process performance of anaerobic side-stream reactor coupled membrane bioreactors: kinetic model, sludge reduction mechanism and microbial community structures
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-10
    Lu-Man Jiang, Zhen Zhou, Tianhao Niu, Lingyan Jiang, Guang Chen, Hongjian Pang, Xiaodan Zhao, Zhan Qiu

    An anoxic/oxic membrane bioreactor (AO-MBR) and three anaerobic side-stream reactor (ASSR) coupled MBRs (ASSR-MBR) were operated to investigate the effects of hydraulic retention time of ASSR (HRTA) and to elucidate sludge reduction mechanisms in ASSR-MBRs. Increasing HRTA from 3.3 to 6.6 h improved nitrogen removal, and enhanced sludge reduction from 8.0% to 40.9% in ASSR-MBR. The sludge decay coefficient was 0.0221 d-1 in MBRs, and 0.0231-0.0345 d-1 in ASSRs. The measured lysis rate coefficient of heterotrophic biomass was 0.083-0.112 d-1 in MBRs and 0.079-0.111 d-1 in ASSRs. The hydrolysis rate coefficient of inactive particulate organic matters (POMs) in ASSRs significantly exceeded that in the MBR. At HRTA of 6.6 h, POMs hydrolysis in ASSR (38.6%) is the dominant route of sludge reduction, and cell lysis occurred principally in aerobic tanks. Illumina-MiSeq sequencing showed ASSR-MBRs enriched hydrolytic and fermentative bacteria, and confirmed that anaerobic hydrolysis contributed most to sludge reduction.

    更新日期:2018-07-12
  • Feasibility of enhancing short-chain fatty acids production from waste activated sludge after free ammonia pretreatment: Role and significance of rhamnolipid
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-10
    Qiuxiang Xu, Xuran Liu, Yingying Fu, Yifu Li, Dongbo Wang, Qilin Wang, Yiwen liu, Hongxue An, Jianwei Zhao, Yanxin Wu, Xiaoming Li, Qi Yang, Guangming Zeng

    This study reported a new, renewable and high-efficient strategy for anaerobic fermentation, i.e., using free ammonia (FA) to pretreat waste activated sludge (WAS) for 1 d and then combining with rhamnolipid (RL), by which the short-chain fatty acids (SCFA) production was remarkably improved. Experimental results showed the maximal SCFA production of 324.7 ± 13.9 mg COD/g VSS was achieved at 62.6 mg FA/L pretreatment combined with 0.04g RL/g TSS, which was respectively 5.95-fold, 1.63-fold and 1.41-fold of that from control, FA pretreatment and RL pretreatment. Mechanism investigations revealed that FA + RL enhanced sludge solubilization and hydrolysis, providing more organics for subsequent SCFA production. It was also found that the combined method inhibited acidogenesis and methanogenesis, but the inhibition to methanogenesis was much severer than that to acidogenesis. Finally, the feasibility of NH+ 4-N and PO3- 4-P, released in fermentation liquor, being recovered as magnesium ammonium phosphate (MAP) was confirmed.

    更新日期:2018-07-12
  • Biofiltration of methane
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-10
    Helen La, J. Patrick A. Hettiaratchi, Gopal Achari, Peter F. Dunfield

    The on-going annual increase in global methane (CH4) emissions can be largely attributed to anthropogenic activities. However, as more than half of these emissions are diffuse and possess a concentration less than 3% (v/v), physical-chemical treatments are inefficient as an abatement technology. In this regard, biotechnologies, such as biofiltration using methane-oxidizing bacteria, or methanotrophs, are a cost-effective and efficient means of combating diffuse CH4 emissions. In this review, a number of abiotic factors including temperature, pH, water content, packing material, empty-bed residence time, inlet gas flow rate, CH4 concentration, as well biotic factors, such as biomass development, are reviewed based on empirical findings on CH4 biofiltration studies that have been performed in the last decades.

    更新日期:2018-07-12
  • Upgrading methane fermentation of food waste by using a hollow fiber type anaerobic membrane bioreactor
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-10
    Hui Cheng, Yutaka Hiro, Toshimasa Hojo, Yu-You Li

    In this study, the effects of organic loading rates (OLRs) on anaerobic fermentation of food waste were comprehensively evaluated using a hollow fiber type anaerobic membrane bioreactor (HF-AnMBR). Compared to other OLRs, biogas production rate was highest at the OLR of 9.72 g-COD/L/d, the organic matter removal efficiency was also significantly higher and VFA was in lower concentration. COD conversion efficiency was as high as 92.9%, 85.3%, 82.6% and 80.4% at OLRs of 2.43, 4.86, 7.29 and 9.72 g-COD/L/d, respectively. The major membrane fouling was caused by organic pore blocking, accounting for 59.6% of the total hydraulic resistance after long-term operation. The performance of HF-AnMBR was compared with a continuously stirred tank reactor (CSTR) and a self-agitated reactor (SAR). The higher operation OLRs, COD conversion efficiency and better effluent quality achieved by the HF-AnMBR are evidences of a significant improvement in reactor performance compared to CSTR and SAR.

    更新日期:2018-07-12
  • The potential of microalgae biorefineries in Belgium and India: an environmental techno-economic assessment
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-10
    Gwenny Thomassen, Miet Van Dael, Steven Van Passel

    This study performs an environmental techno-economic assessment (ETEA) for multiple microalgae biorefinery concepts at different locations, those being Belgium and India. The ETEA methodology, which integrates aspects of the TEA and LCA methodologies and provides a clear framework for an integrated assessment model, has been proposed and discussed. The scenario in India has a higher profitability with a NPV of €40 million over a period of 10 years, while the environmental impact in Belgium is lower. The inclusion of a medium recycling step provides the best scenario from both perspectives. The crucial parameters for feasibility are the β-carotene price and content, the upstream environmental impact of electricity and the maximum biomass concentration during cultivation. The identification of these parameters by the ETEA guides future technology developments and shortens the time-to-market for microalgal-based biorefineries.

    更新日期:2018-07-12
  • Pretreatment with concurrent UV photocatalysis and alkaline H2O2 enhanced the enzymatic hydrolysis of sisal waste
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-10
    Yishuo Yang, Jian Yang, Jing cao, Zhaomei Wang

    This work studied a concurrent UV photocatalysis and alkaline H2O2 pretreatment (UHP) to enhance the subsequent enzymatic hydrolysis of sisal waste in comparison with alkaline H2O2 pretreatment (AHP). An optimal condition was identified for UHP at H2O2 charge 0.1 g/g dried sisal waste, pH 10.0, and UV radiation for 6 h. Under this condition, UHP led to a delignification rate of 76.6%, a conversion to reducing sugar at 71.2%, and a conversion to glucose at 91.6%, respectively. XRD, FT-IR and SEM analysis showed an increase in crystalline degree and significant changes in the structure of sisal during UHP. The current study implicates that UHP is more efficient than AHP in pretreating sisal waste, with reduced H2O2 charge, shortened pretreatment time, and enhanced enzymatic digestibility.

    更新日期:2018-07-12
  • Impact of lignin content on alkaline-sulfite pretreatment of Hybrid Pennisetum
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-10
    Jingfeng Wang, Xixun Hao, Ming Yang, Yujie Qin, Lili Jia, Jie Chu, Junhua Zhang

    This work focuses to investigate the impact of lignin content on chemical compositions, crystallinity, surface characterizations, cellulase adsorption profiles and hydrolysability of Hybrid Pennisetum (HP) after alkaline sulfite pretreatment (ASP). For the HP with lower lignin content, the increase of the cellulose content by ASP was more obvious than raw HP. ASP decreased total lignin content and surface lignin content of HP substrates. HP with lower lignin content (e.g., ∼15%) is suitable for ASP, because a pretty perfect glucose yield (91%) was obtained using a low dosage of enzyme loadings (5 FPU of cellulases/g dry matter). The study provides a potential strategy to efficiently produce platform sugars from HP with reduced lignin content, indicating the importance of reduction HP lignin content properly by breeding or transgenesis programs. The work could also help elucidate the mechanism of alkaline sulfite pretreatment for efficient production of fermentable sugars from lignocelluloses.

    更新日期:2018-07-12
  • Phosphoric acid-activated wood biochar for catalytic conversion of starch-rich food waste into glucose and 5-hydroxymethylfurfural
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-10
    Leichang Cao, Iris K.M. Yu, Daniel C.W. Tsang, Shicheng Zhang, Yong Sik Ok, Eilhann E. Kwon, Hocheol Song, Chi Sun Poon

    The catalytic activity of engineered biochar was scrutinized for generation of glucose and hydroxymethylfurfural (HMF) from starch-rich food waste (bread, rice, and spaghetti). The biochar catalysts were synthesized by chemical activation of pinewood sawdust with phosphoric acid at 400-600 °C. Higher activation temperatures enhanced the development of porosity and acidity (characterized by C–O–PO3 and C–PO3 surface groups), which imparted higher catalytic activity of H3PO4-activated biochar towards starch hydrolysis and fructose dehydration. Positive correlations were observed between HMF selectivity and ratio of mesopore to micropore volume, and between fructose conversion and total acid density. High yields of glucose (86.5 Cmol% at 150 °C, 20 min) and HMF (30.2 Cmol% at 180 °C, 20 min) were produced from rice starch and bread waste, respectively, over H3PO4-activated biochar. These results highlighted the potential of biochar catalyst in biorefinery as an emerging application of engineered biochar.

    更新日期:2018-07-12
  • Performances Study of UV/O3-aMBR Recirculation System in Treating Polluted Surface Water
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-10
    Lu Li, Kang Song, C. Visvanathan

    This study used UV/O3-aMBR system for treating polluted surface water with CODMn around 10 mg/L, to improve the removal of non-biodegradable components. UV/O3 was used in the recirculation stream, partially treating the recalcitrant in aMBR permeate to improve its biodegradability, and then send back to aMBR for biodegradation. Removal performance of UV/O3-aMBR system with recirculation ratio 20, 40, 60 and 80% was tested and compared. The removal of CODMn, UV254, NH3-N and color increased with the increment of recirculation ratio. UV/O3-aMBR system has higher recalcitrant removal performance and less membrane fouling. The fluorescent dissolved organic matter (FDOM) was largely reduced in UV/O3-aMBR system, and the system hydrophilicity was higher than aMBR system. The Modified Stover Kincanoon model was able to describe UV/O3-aMBR system; and has higher Umax than aMBR system. UV/O3-aMBR can be develop as an effective technology in improving recalcitrant removal in polluted surface water treatment.

    更新日期:2018-07-12
  • Application of anaerobic membrane bioreactors to municipal wastewater treatment at ambient temperature: a review of achievements, challenges, and perspectives
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-10
    Zhen Lei, Shuming Yang, Yuyou Li, Wen Wen, Xiaochang C. Wang, Rong Chen

    This review surveys the implementation of anaerobic membrane bioreactors in municipal wastewater treatment at ambient temperature. High chemical oxygen demand (COD) removal efficiencies and methane conversion rates were achieved under various conditions, while also achieving a low sludge yield of 0.04–0.09 g volatile suspended solids (VSS)/g COD. A survey of energy demands for pilot-scale anaerobic membrane bioreactors showed that they could be energy neutral or even positive, even though high energy (0.08–0.35 kWh/ m3) is required to clear membrane fouling. Thus, the use of anaerobic membrane bioreactors in municipal wastewater treatment at ambient temperature is very promising. However, some challenges such as membrane fouling control, methane in effluent, low COD/ SO42–-S ratio, and deficiencies in alkalinity should be addressed, especially the latter. Future research perspectives relating to the challenges and further research are proposed.

    更新日期:2018-07-12
  • A new process for simultaneous nitrogen removal and phosphorus recovery using an anammox expanded bed reactor
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-11
    Haiyuan Ma, Yanlong Zhang, Yi Xue, Yu-You Li

    Phosphorus recovery from wastewater is an important approach for sustainable phosphorus use. In this work, a process combining anammox and hydroxyapatite (HAp) precipitation in an expanded bed reactor for simultaneous nitrogen removal and phosphorus recovery was developed by applying specific Ca/P ratio and pH control. A high phosphorus removal rate (0.14±0.01 kg-P/m3/d) was obtained while a stable nitrogen removal efficiency (87.4±2.9%) maintained with an effluent recirculation system applied. Average 13.4% phosphorus (30.7% in P2O5) accumulation in the dry sludge and a Ca/P ratio very close to HAp was observed by quantitative elemental analysis. In this work, different analysis revealed the two layers structure with anammox biofilm attached to inorganic core of the granules. Different spectral analysis determined the major phase of the inorganic content as hydroxyapatite. With proper Ca/P ratio and pH control, anammox expanded bed reactor was transformed into an efficient process to simultaneously remove nitrogen and recover phosphorus.

    更新日期:2018-07-12
  • Improving the co-digestion performance of waste activated sludge and wheat straw through ratio optimization and ferroferric oxide supplementation
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-11
    Zisheng Zhao, Yang Li, Xie Quan, Yaobin Zhang

    Low anaerobic digestion efficiency of wheat straw (WS) has been an intractable problem owing to its high C/N ratio and complex structure. In this study, co-digestion of WS and waste activated sludge (WAS) at different ratios was performed to identify conditions that would elevate the acidic pH and increase methane production. The results showed that using a 1:1 ratio of WS and WAS, methane production in the co-digester was 26.9% higher than the sum of equal WAS and WS mono-digestion. When Fe3O4 was added to the co-digester, the acidic pH was further relieved and the anaerobic digestion efficiency was additionally enhanced. Microbial analysis showed that the ethanol-type fermentative bacterial genus Ethanoligenens was enriched in the WAS+WS-Fe3O4 reactor, in which the production of propionate was notably reduced, indicating that Fe3O4 could prevent the accumulation of volatile fatty acids by changing the types of fermentative bacteria present and promote anaerobic digestion efficiency.

    更新日期:2018-07-12
  • Bio-based volatile fatty acid production and recovery from waste streams: current status and future challenges
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-11
    Merve Atasoy, Isaac Owusu-Agyeman, Elzbieta Plaza, Zeynep Cetecioglu

    Bio-based volatile fatty acid (VFA) production from waste-stream is getting attention due to increasing market demand and wide range usage area as well as its cost-effective and environmentally friendly approach. The aim of this paper is to give a comprehensive review of bio-based VFA production and recovery methods and to give an opinion on future research outlook. Effects of operation conditions including pH, temperature, retention time, type of substrate and mixed microbial cultures on VFA production and composition were reviewed. The recovery methods in terms of gas stripping with absorption, adsorption, solvent extraction, electrodialysis, reverse osmosis, nanofiltration, and membrane contractor of VFA were evaluated. Furthermore, strategies to enhance bio-based VFA production and recovery from waste streams, specifically, in-line VFA recovery and bioaugmentation which are currently not used in common practice, are seen as some of the approaches to enhance bio-based VFA production.

    更新日期:2018-07-12
  • Response of antibiotic and heavy metal resistance genes to two different temperature sequences in anaerobic digestion of waste activated sludge
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-11
    Hyun Min Jang, Jangwoo Lee, Sangki Choi, Jingyeong Shin, Eunsung Kan, Young Mo Kim

    Response of antibiotic resistance genes (ARGs) and heavy metal resistance genes (HMRGs) to two different temperature sequences (i.e., mesophilic-thermophilic and thermophilic-mesophilic) were investigated. Higher removal of total ARGs (twenty-one targeted subtypes) and HMRGs (three targeted subtypes) was achieved by the mesophilic-thermophilic sequence than by the thermophilic-mesophilic sequence. The sequence of mesophilic-thermophilic showed the highest removal of total ARGs, but the sequence of thermophilic-mesophilic proved more suitable for removal of class 1 integrons (intI1). Correlation analysis indicated that intI1 correlated significantly with tetG, tetQ, tetX, sul2, aac(6')-lb-cr, blaTEM, ermB and floR. High-throughput sequencing revealed that the mesophilic-thermophilic sequence TPAD removed more human bacterial pathogens (HBPs) than did the thermophilic-mesophilic sequence. Also, significantly positive correlation was observed between ARGs and HBPs. For instance, Mycoplasma pneumonia showed significantly positive correlation with several ARGs including tetE, tetQ, tetX, tetZ, sul1, sul2, aac(6')-lb-cr and floR.

    更新日期:2018-07-12
  • Dual function of ammonium acetate in acetone-butanol-ethanol fermentation by Clostridium acetobutylicum
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-11
    Shubo Li, Yuan Zhou, Zhiting Luo, Yanyan Cui, Yu Xu, Lihua Lin, Mouming Zhao, Yuan Guo, Zongwen Pang

    In this study, a compound nitrogen source, integrating the advantages of ammonium acetate and soybean meal, was proposed to further improve acetone-butanol-ethanol fermentation. Unfortunately, this compound nitrogen source was found to effectively inhibit cellular performance, as the introduction of NH4+ significantly decreased the yield of butanol and total solvents by 34.78% and 35.14%, to only 6.62 g/L and 10.76 g/L, respectively. Meanwhile, the regulatory mechanism was further elucidated at different levels. As a result, the NH4+ could down-regulate the transcriptional levels of key genes involved in butanol synthesis, and the activity of acetoacetyl-CoA/acyl-CoA transferase, and then decrease the accumulation of key intermediates. Therefore, ammonium acetate has a dual function in ABE fermentation, as it effectively improves ABE fermentation when it is the sole nitrogen source but significantly decreases fermentation performance in the presence of soybean meal, broadening the understanding of nitrogen regulation mechanism of C. acetobutylicum.

    更新日期:2018-07-12
  • Insights into the economic viability of cellulases recycling on bioethanol production from recycled paper sludge
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-12
    Daniel G. Gomes, Sebastián Serna-Loaiza, Carlos A. Cardona, Miguel Gama, Lucília Domingues

    The economics of Recycled Paper Sludge conversion into ethanol was here assessed with emphasis on integrating a cellulase recycling system. Without cellulases recycling this process presented positive economic outputs (payback period of 7.85 years; 10.90 Million US$ of accumulated NPV) despite the modest ethanol titers. Recycling both free and solid-bound enzymes allowed considerable savings of enzyme but also an increase on annual costs (0.88 %), resulting on a superior economic output: payback period decreased to 7.25 years; accumulated NPV increased to 14.44 Million US$. Recycling exclusively the liquid fraction enabled a clear costs reduction, however, also total ethanol decreased, attenuating the abovementioned benefits. Targeting higher ethanol concentrations, superior solids consistencies were also evaluated. Despite a costs reduction, total ethanol decreased due to a higher ethanol retention on the solid. A sensitivity analysis further revealed that the cost of enzymes and ultrafiltration membrane may be critical on enzyme recycling economic feasibility.

    更新日期:2018-07-12
  • Arundo donax L. can substitute traditional energy crops for more efficient, environmentally-friendly production of biogas: a Life Cycle Assessment approach
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-12
    Giuliana D'Imporzano, Roberto Pilu, Luca Corno, Fabrizio Adani

    Maize silage contributes to biogas production in Lombardy Region (400 anaerobic digestion plants) employing 47,000 Ha (Production Model – PM1). Reducing the area devoted to this energy crop is a goal to free soil for food production. Double cropping (PM2) and Arundo donax L. (PM3) have been proposed and tested to measure the impacts for the three Production Models by Life Cycle Assessment (LCA). The impact category related to Climate Change remained stable for PM2 while it decreased by 17% for Arundo donax L. (PM3) in comparison with PM1. Impact categories related to nutrient management (acidification, particulate matter eutrophication) showed an increase in the range of 3-5% for PM2 in comparison with PM1, while Arundo donax L. allowed the same impact categories to be reduced by 31%, 24%, 17% and 33%, respectively.

    更新日期:2018-07-12
  • Relationships between galvanic interaction, copper extraction and community dynamics during bioleaching of chalcopyrite by a moderately thermophilic culture
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-05
    Yuguang Wang, Xinhua Chen, Hongbo Zhou

    A moderately thermophilic culture was enriched and adapted to bioleach chalcopyrite at high pulp density. In order to further improve copper extraction, effects of galvanic interaction on bioleaching performance and community dynamics were investigated by adding pyrite. Copper extractions were improved by 2.91 and 1.97 times in the initial and the final stages when pyrite was present, respectively. However, it did not benefit chalcopyrite dissolution in the middle stage. Community dynamics analysis showed that succession of the attached cells was significantly different from community dynamics of the planktonic cells. One of planktonic populations always dominated the communities in most cases, while no species had absolutely competitive advantages in the attached communities. In addition, the presence of pyrite had significant effects on planktonic and attached community structures, and could accelerate planktonic community succession.

    更新日期:2018-07-08
  • New insight of tertiary-amine modified bentonite amendment on the nitrogen transformation and volatile fatty acids during the chicken manure composting
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-05
    Xiuna Ren, Mukesh Kumar Awasthi, Quan Wang, Junchao Zhao, Ronghua Li, Zhineng Tu, Hongyu Chen, Sanjeev Kumar Awasthi, Zengqiang Zhang

    In this study, the main objective was to investigate the potential effect of tertiary-amine modified bentonite (TAMB) on the nitrogen transformation and the volatile fatty acids (VFAs) degradation during the chicken manure (CM) composting. Six dosages of TAMB (0%, 2%, 4%, 6%, 8% and 10%) were amended into the mixture of CM and wheat straw and then composted for 50 days. The results revealed the TAMB amendment could prolong the thermophilic phase and enhance the organic matter (OM) degradation. With the increasing dosage of TAMB, the ammonia volatilization was reduced by 15.41%-65.35%. Meanwhile, the TAMB addition had a positive effect on VFAs degradation and reducing odor unitMAX (OUMAX) by 17.61%-59.24%. Moreover, CH4 was reduced by 12.15%-32.78% in TAMB applied treatments compared to control. Finally, combined with all results, it indicated that TAMB amendment could reduce VFAs, CH4 emission and nitrogen loss to improve the compost quality.

    更新日期:2018-07-08
  • Bioprocess development for biolubricant production using microbial oil derived via fermentation from confectionery industry waste
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-06
    Aikaterini Papadaki, Keysson Vieira Fernandes, Afroditi Chatzifragkou, Erika Cristina Gonçalves Aguieiras, José André Cavalcanti da Silva, Roberto Fernandez-Lafuente, Seraphim Papanikolaou, Apostolis Koutinas, Denise Maria Guimarães Freire

    Microbial oil produced from confectionery and wheat milling side streams has been evaluated as novel feedstock for biolubricant production. Nutrient-rich fermentation media were produced by a two-step bioprocess involving crude enzyme production by solid state fermentation followed by enzymatic hydrolysis of confectionery industry waste. Among 5 yeast strains and 2 fungal strains cultivated on the crude hydrolysate, Rhodosporidium toruloides and Cryptococcus curvatus were selected for further evaluation for biolubricant production based on fermentation efficiency and fatty acid composition. The extracted microbial oils were enzymatically hydrolysed and the free fatty acids were esterified by Lipomod 34-MDP in a solvent-free system with trimethylolpropane (TMP) and neopentyl glycol (NPG). The highest conversion yields were 88% and 82.7% for NPG esters of R. toruloides and C. curvatus, respectively. This study also demonstrates that NPG esters produced from microbial oil have promising physicochemical properties for bio-based lubricant formulations that could substitute for conventional lubricants.

    更新日期:2018-07-08
  • Reduction of Gibbs free energy and enhancement of Methanosaeta by bicarbonate to promote anaerobic syntrophic butyrate oxidation
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-06
    Yupeng Zhang, Jianzheng Li, Fengqin Liu, Han Yan, Jiuling Li, Xue Zhang

    Bicarbonate (HCO3–) has been extensively researched as a buffer in anaerobic digestion. The effect of HCO3– concentration on syntrophic butyrate oxidation process was evaluated by batch culturing of anaerobic activated sludge, and the mechanism was further revealed by the changes of Gibbs free energy (ΔG) and the interspecies transfers of electron and proton. The results showed that butyrate degradation rate was enhanced by 32.07% when the supplement of HCO3– increased from 0 to 0.20 mol/L. However, methane production and acetate degradation were strongly inhibited by HCO3– more than 0.10 mol/L. More function of HCO3– was found as 1) decreasing the ΔG of syntrophic methanogenesis of butyrate while increasing the ΔG of methanogenesis of acetate, 2) enriching M. harundinacea and M. concilii, 3) increasing the diffusion rate of protons between the syntrophic consortia. This work would increase the anaerobic digestion efficiency by enhancing the interaction of the syntrophic consortia.

    更新日期:2018-07-08
  • Effect of Nickel-containing Activated Carbon on Food Waste Anaerobic Digestion
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-06
    Jae Hac Ko, Ning Wang, Tugui Yuan, Fan Lü, Pinjing He, Qiyong Xu

    Anaerobic digestion (AD) is frequently restricted with the long lag phase and low methane (CH4) production rate. Laboratory batch experiments were conducted to investigate the impact of different supplements on the performance of food waste AD, including AC-Ni, AC, and Ni. Results showed that the lag phase of AD was reduced with the addition of those supplementations. Compared with the control group without any supplementation, the AC-Ni could shorten the lag phase by 67% and increase the maximum CH4 production rate by 50%, respectively. The speciation analysis indicated that the environmental risks of the AC-Ni was reduced by 30% after digestion. Microbial community structure analysis revealed that the AC-Ni promoted the evolution and activity of the hydrolytic-fermentative bacteria (e.g. Firmicutes and Bacteroidetes) and methanogens (e.g. Methanobacterium, Methanoregula and Methanomassiliicoccus). This study suggested that the AC-Ni waste could be feasible to be applied to enhance the performance of AD.

    更新日期:2018-07-08
  • Synthesis of novel modified magnetic chitosan particles and their adsorption performance toward Cr(VI)
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-06
    Chaofan Zheng, Huaili Zheng, Yongjuan Wang, Yili Wang, Wenqi Qu, Qiang An, Yongzhi Liu

    Novel adsorbents, poly([2-(methacryloxy)ethyl]trimethylammonium chloride) modified magnetic chitosan particles (DMCPs), were synthesized via free radical polymerization and applied to adsorb Cr(VI) from aqueous solution. The effects of pH (2-11), Cr(VI) concentration (10-200 mg/L) and contact time (0-420 min) on the adsorption performance were evaluated. The results showed that the adsorption capacity of DMCPs was much larger than that of magnetic chitosan particles (MCPs) in the examined pH range and decreased with Cl- concentration increasing, indicating that electrostatic interaction and ion exchange are the governing mechanisms of Cr(VI) adsorption by DMCPs. The Langmuir isotherm model and pseudo-second-order kinetic model fitted the experimental data well. The maximum adsorption capacity of DMCPs is 153.85 mg/g. Besides, Cr(VI)-loaded DMCPs could be easily separated and efficiently regenerated. Therefore, DMCPs are promising candidates for Cr(VI) adsorption owing to their excellent performance in a wide pH range, easy separation and good reusability.

    更新日期:2018-07-08
  • A Critical Review of One-stage Anammox Processes for Treating Industrial Wastewater: Optimization Strategies Based on Key Functional Microorganisms
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-06
    Jianwei Li, Jialin Li, Ruitao Gao, Ming Wang, Lan Yang, Xiaoling Wang, Liang Zhang, Yongzhen Peng

    The one-stage nitritation/anammox (anaerobic ammonium oxidation) process is an energy-saving technology, which has been successfully developed and widely applied to treat industrial wastewaters. For the one-stage nitritation/anammox process, key functional microbes generally include anaerobic ammonia oxidation bacteria (AnAOB), ammonia-oxidizing bacteria (AOB), nitrite oxidizing bacteria (NOB), and heterotrophic bacteria (HB). Cooperation and competition among the key functional microbes are critical to the stability and performance of anammox process. Based upon key functional microorganisms, this review summarizes and discusses the optimized strategies that promote the operation of one-stage nitritation/anammox process. In particular, the review focuses on strategies related to: (1) the retention of anammox biomass through granular sludge or biofilm, (2) the balanced relationship between AOB and AnAOB, (3) the NOB suppression and (4) the HB management by controlling the influent organic matter. In addition, the review proposes further research to address the existing challenges.

    更新日期:2018-07-08
  • Simultaneous removal of thiocyanate and nitrogen from wastewater by autotrophic denitritation process
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-06
    Jianxin Pan, Jingde Ma, Haizhen Wu, Yuan Ren, Bingbing Fu, Meiling He, Shuang Zhu, Chaohai Wei

    Pollutants containing sulfur as electron donors will play an important role in the energy-saving denitritation process when organic carbon source was insufficient in wastewater. However, thiocyanate (SCN-), a hazardous pollutant, has not been characterized in denitritation. In this study, the effects of key environmental factors on removal of thiocyanate and nitrogen were investigated in denitritation. The results showed that the maximum removal efficiency of nitrogen was observed in complete removal of thiocyanate and nitrite. The elemental sulfur was observed prior to complete depletion of thiocyanate. The efficiency of denitritation was promoted by NaHCO3 and weakly-alkaline environment. In the sludge containing dominant Thiobacillus genus, nitrite was reduced in the conversion of thiocyanate into elemental sulfur and further into sulfate. The stoichiometric ratio of NO2--N to SCN--N was close to 2.0 when thiocyanate was converted completely into sulfate, which verified complete removal of thiocyanate and nitrite at the NO2--N/SCN--N ratio of 2.0.

    更新日期:2018-07-08
  • Intensified heterotrophic denitrification in constructed wetlands using four solid carbon sources: Denitrification efficiency and bacterial community structure
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-07
    Zhihao Si, Xinshan Song, Yunhui Wang, Xin Cao, Yufeng Zhao, Bodi Wang, Yan Chen, Awet Arefe

    Biodenitrification using solid carbon sources is a cost-effective way for nitrate removal. In the study, wheat straw, cotton, poly(butylene succinate), and newspaper was chosen as the carbon source to compare the denitrification efficiency and bacterial communities in constructed wetlands. Parameters including COD, NO3--N, NO2--N and total nitrogen (TN) were analyzed. Results indicated that newspaper provided significantly higher NO3--N and TN removal efficiency than the other three solid carbon sources in low-temperature condition. Moreover, both newspaper and wheat straw allowed high NO3--N and TN removal efficiency in high-temperature condition. According to pyrosequencing analysis, denitrifying bacteria Dechloromonas and Thauera were the predominant genus in the anaerobic zone of CO- (3.92 and 2.35%, respectively), WS- (1.97 and 1.02%, respectively) and NP-CWs (1.71 and 1.31%, respectively). Genus of Levilinea was enriched in NP- (1.02%) and WS-CWs (0.91%). Furthermore, genus Paludibacter (2.69%) and Saccharofermentans (3.14%) showed high relative abundance in WS-CWs.

    更新日期:2018-07-08
  • Approaches and processes for ammonia removal from side-streams of municipal effluent treatment plants
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-07
    Cigdem Eskicioglu, Giampiero Galvagno, Caroline Cimon

    The main objective of this review article is to provide a comprehensive view on various conventional and emerging side-stream ammonia removal treatment options for municipal wastewater treatment plants (WWTPs). Optimization of wastewater treatment facilities from an energy and emissions stand-point necessitates consideration of the impact of the various internal side-streams. Side-streams from anaerobic sludge digesters in particular have the potential to be a significant ammonium load to the mainstream treatment process. However, the literature suggests that managing side-streams through their treatment in the mainstream process is not the most energy efficient approach, nor does it allow for practical recovery of nutrients. Furthermore, as effluent criteria become more stringent in some jurisdictions and sludge hydrolysis pre-treatment for digesters more common, an understanding of treatment options for ammonia in digester supernatant becomes more important. Given these considerations, a variety of side-stream treatment processes described in the literature are reviewed.

    更新日期:2018-07-08
  • Disintegration of waste activated sludge with composite ferrate solution: sludge reduction and settleability
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-07
    Yanping Zhang, Ruiqi Hu, Jiayu Tian, Tiantian Li

    Sludge reduction has been a key issue in waste activated sludge (WAS) treatment. In this study, composite ferrate solution (CFS) has been used to disintegrate WAS. The results showed that CFS could effectively disrupt sludge flocs and cells and caused the release of intracellular matter such as SCOD, cations and organic acids. These results showed that the sludge disintegration process could be divided into a rapid reaction stage (0-2 hours) and a slow reaction stage (2-24 hours). It was determined that at a CFS dosage of 50 mg Fe/g SS and a reaction time of 24 hours, the sludge reduction was 55.4% and SV and SVI were reduced by 12.1% and 46.4%, respectively. The Fe(VI), ClO- and OH- in CFS all played important roles in sludge decomposition, but they did not have synergistic effects. The small-particle sludge, in situ formed Fe3+ and released Ca2+ could improve the sludge settleability.

    更新日期:2018-07-08
  • The effects of algal extracellular substances on algal growth, metabolism and long-term medium recycle, and inhibition alleviation through ultrasonication
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-07
    Ze Yu, Haiyan Pei, Qingjie Hou, Changliang Nie, Lijie Zhang, Zhigang Yang, Xiaodong Wang

    The algal extracellular substances (AESs), mainly excreted in the lag and stationary phases, inhibited the algal growth and culture recycle. The AESs consisted of protein-like substances and saccharides, which restrained the algal lipid and protein biosynthesis. Moreover, the increasing reactive oxygen species and anti-oxidative enzymes caused by AESs led to the oxidative damage and suppressed the cell activity. The AESs affected the cells through two possible ways: one is the AESs adhered to the cell surfaces; another is the cells yielded signal molecules in response to the AESs. Fortunately, the ultrasound degraded the AESs into small molecules, which clearly alleviated the limitation and recovered the algal biomass and metabolism to recover. This study demonstrated that ultrasonication is a promising way to alleviate the AESs, which facilitating the medium recycle for long-term continuous microalgae production.

    更新日期:2018-07-08
  • Micro-oxygen bioanode: an efficient strategy for enhancement of phenol degradation and current generation in mix-cultured MFCs
    Bioresource Technol. (IF 5.807) Pub Date : 2018-07-07
    Li-Hui Yang, Ting-Ting Zhu, Wei-Wei Cai, Muhammad Rizwan Haider, Hong-Cheng Wang, Hao-Yi Cheng, Ai-Jie Wang

    It is controversial to introduce oxygen into anode chamber as oxygen would decrease the CE (Coulombic efficiency) while it could also enhance the degradation of aromatics in microbial fuel cell (MFCs). Therefore, it is important to balance the pros and cons of oxygen in aromatics driven MFCs. A RMO (micro-oxygen bioanode MFC) was designed to determine the effect of oxygen on electricity output and phenol degradation. The RMO showed 6-fold higher phenol removal efficiency, 4-fold higher current generation than the RAN (anaerobic bioanode MFC) at a cost of 26.9% decline in CE. The Zoogloea and Geobacter, which account for phenol degradation and current generation, respectively, were dominated in the RMO bioanode biofilm. The biomass also showed great difference between RMO and RAN (114.3±14.1 vs. 2.2±0.5 nmol/g). Therefore, different microbial community, higher biomass as well as the different degradation pathway were suggested as reasons for the better performance in RMO.

    更新日期:2018-07-08
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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