1
|
Zhu Y, Guo M, Qi X, Li M, Guo M, Jia X. Enhanced degradation and methane production of food waste anaerobic digestate using an integrated system of anaerobic digestion and microbial electrolysis cells for long-term operation. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:39637-39649. [PMID: 38829499 DOI: 10.1007/s11356-024-33525-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 04/27/2024] [Indexed: 06/05/2024]
Abstract
The integrated system of anaerobic digestion and microbial electrolysis cells (AD-MEC) was a novel approach to enhance the degradation of food waste anaerobic digestate and recover methane. Through long-term operation, the start-up method, organic loading, and methane production mechanism of the digestate have been investigated. At an organic loading rate of 4000 mg/L, AD-MEC increased methane production by 3-4 times and soluble chemical oxygen demand (SCOD) removal by 20.3% compared with anaerobic digestion (AD). The abundance of bacteria Fastidiosipila and Geobacter, which participated in the acid degradation and direct electron transfer in the AD-MEC, increased dramatically compared to that in the AD. The dominant methanogenic archaea in the AD-MEC and AD were Methanobacterium (44.4-56.3%) and Methanocalculus (70.05%), respectively. Geobacter and Methanobacterium were dominant in the AD-MEC by direct electron transfer of organic matter into synthetic methane intermediates. AD-MEC showed a perfect SCOD removal efficiency of the digestate, while methane as clean energy was obtained. Therefore, AD-MEC was a promising technology for deep energy transformation from digestate.
Collapse
Affiliation(s)
- Yusen Zhu
- State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing, 100048, China
| | - Meixin Guo
- State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing, 100048, China
| | - Xuejiao Qi
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China
| | - Mingxiao Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Meng Guo
- State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing, 100048, China
| | - Xuan Jia
- State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing, 100048, China.
| |
Collapse
|
2
|
Lemaigre S, Gerin PA, Adam G, Klimek D, Goux X, Herold M, Frkova Z, Calusinska M, Delfosse P. Potential of acetic acid to restore methane production in anaerobic reactors critically intoxicated by ammonia as evidenced by metabolic and microbial monitoring. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:188. [PMID: 38042839 PMCID: PMC10693713 DOI: 10.1186/s13068-023-02438-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 11/21/2023] [Indexed: 12/04/2023]
Abstract
BACKGROUND Biogas and biomethane production from the on-farm anaerobic digestion (AD) of animal manure and agri-food wastes could play a key role in transforming Europe's energy system by mitigating its dependence on fossil fuels and tackling the climate crisis. Although ammonia is essential for microbial growth, it inhibits the AD process if present in high concentrations, especially under its free form, thus leading to economic losses. In this study, which includes both metabolic and microbial monitoring, we tested a strategy to restore substrate conversion to methane in AD reactors facing critical free ammonia intoxication. RESULTS The AD process of three mesophilic semi-continuous 100L reactors critically intoxicated by free ammonia (> 3.5 g_N L-1; inhibited hydrolysis and heterotrophic acetogenesis; interrupted methanogenesis) was restored by applying a strategy that included reducing pH using acetic acid, washing out total ammonia with water, re-inoculation with active microbial flora and progressively re-introducing sugar beet pulp as a feed substrate. After 5 weeks, two reactors restarted to hydrolyse the pulp and produced CH4 from the methylotrophic methanogenesis pathway. The acetoclastic pathway remained inhibited due to the transient dominance of a strictly methylotrophic methanogen (Candidatus Methanoplasma genus) to the detriment of Methanosarcina. Concomitantly, the third reactor, in which Methanosarcina remained dominant, produced CH4 from the acetoclastic pathway but faced hydrolysis inhibition. After 11 weeks, the hydrolysis, the acetoclastic pathway and possibly the hydrogenotrophic pathway were functional in all reactors. The methylotrophic pathway was no longer favoured. Although syntrophic propionate oxidation remained suboptimal, the final pulp to CH4 conversion ratio (0.41 ± 0.10 LN_CH4 g_VS-1) was analogous to the pulp biochemical methane potential (0.38 ± 0.03 LN_CH4 g_VS-1). CONCLUSIONS Despite an extreme free ammonia intoxication, the proposed process recovery strategy allowed CH4 production to be restored in three intoxicated reactors within 8 weeks, a period during which re-inoculation appeared to be crucial to sustain the process. Introducing acetic acid allowed substantial CH4 production during the recovery period. Furthermore, the initial pH reduction promoted ammonium capture in the slurry, which could allow the field application of the effluents produced by full-scale digesters recovering from ammonia intoxication.
Collapse
Affiliation(s)
- Sébastien Lemaigre
- Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, Rue du Brill 41, L-4422, Belvaux, Luxembourg.
| | - Patrick A Gerin
- Earth and Life Institute, Bioengineering, Université Catholique de Louvain, Croix du Sud 2, Box L7.05.19, B-1348, Louvain-la-Neuve, Belgium
| | - Gilles Adam
- Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, Rue du Brill 41, L-4422, Belvaux, Luxembourg
| | - Dominika Klimek
- Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, Rue du Brill 41, L-4422, Belvaux, Luxembourg
| | - Xavier Goux
- Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, Rue du Brill 41, L-4422, Belvaux, Luxembourg
| | - Malte Herold
- Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, Rue du Brill 41, L-4422, Belvaux, Luxembourg
| | - Zuzana Frkova
- Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, Rue du Brill 41, L-4422, Belvaux, Luxembourg
| | - Magdalena Calusinska
- Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, Rue du Brill 41, L-4422, Belvaux, Luxembourg
| | - Philippe Delfosse
- Université du Luxembourg, Campus Belval, Maison du Savoir, Avenue de l'Université 2, L-4365, Esch-sur-Alzette, Luxembourg
| |
Collapse
|
3
|
Yan M, Hu Z, Duan Z, Sun Y, Dong T, Sun X, Zhen F, Li Y. Microbiome re-assembly boosts anaerobic digestion under volatile fatty acid inhibition: focusing on reactive oxygen species metabolism. WATER RESEARCH 2023; 246:120711. [PMID: 37844339 DOI: 10.1016/j.watres.2023.120711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 10/02/2023] [Accepted: 10/07/2023] [Indexed: 10/18/2023]
Abstract
The accumulation of volatile fatty acids (VFAs) in anaerobic digestion (AD) systems resulting from food waste overload poses a risk of system collapse. However, limited understanding exists regarding the inhibitory mechanisms and effective strategies to address VFAs-induced stress. This study found that accumulated VFAs exert reactive oxygen species (ROS) stress on indigenous microbiota, particularly impacting methanogens due to their lower antioxidant capability compared to bacteria, which is supposed to be the primary reason for methanogenesis failure. To enhance the VFAs-stressed AD process, microbiome re-assembly using customized propionate-degrading consortia and bioaugmentation with concentrated digestate were implemented. Microbiome re-assembly demonstrated superior efficiency, yielding an average methane yield of 563.6±159.8 mL/L·d and reducing VFAs to undetectable levels for a minimum of 80 days. This strategy improved the abundance of Syntrophomonas, Syntrophobacter and Methanothrix, alleviating ROS stress. Conversely, microbial community in reactor with other strategy experienced an escalating intracellular damage, as indicated by the increase of ROS generation-related genes. This study fills knowledge gaps in stress-related metabolic mechanisms of anaerobic microbiomes exposed to VFAs and microbiome re-assembly to boost methanogenesis process.
Collapse
Affiliation(s)
- Miao Yan
- Laboratory of Biomass Bio-Chemical Conversion, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, PR China; Shandong Minhe Biotechnology Co., Ltd
| | - Zhiyuan Hu
- Laboratory of Biomass Bio-Chemical Conversion, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, PR China
| | - Zhenhan Duan
- South China Institute of Environmental Science, Ministry of Ecology and Environment, Guangdong 510655 , PR China
| | - Yongming Sun
- Laboratory of Biomass Bio-Chemical Conversion, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, PR China
| | | | | | - Feng Zhen
- Laboratory of Biomass Bio-Chemical Conversion, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, PR China
| | - Ying Li
- Laboratory of Biomass Bio-Chemical Conversion, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, PR China.
| |
Collapse
|
4
|
Fan L, Peng W, Duan H, Lü F, Zhang H, He P. Presence and role of viruses in anaerobic digestion of food waste under environmental variability. MICROBIOME 2023; 11:170. [PMID: 37537690 PMCID: PMC10401857 DOI: 10.1186/s40168-023-01585-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 05/28/2023] [Indexed: 08/05/2023]
Abstract
BACKGROUND The interaction among microorganisms in the anaerobic digestion of food waste (ADFW) reactors lead to the degradation of organics and the recycling of energy. Viruses are an important component of the microorganisms involved in ADFW, but are rarely investigated. Furthermore, little is known about how viruses affect methanogenesis. RESULTS Thousands of viral sequences were recovered from five full-scale ADFW reactors. Gene-sharing networks indicated that the ADFW samples contained substantial numbers of unexplored anaerobic-specific viruses. Moreover, the viral communities in five full-scale reactors exhibited both commonalities and heterogeneities. The lab-scale dynamic analysis of typical ADFW scenarios suggested that the viruses had similar kinetic characteristics to their prokaryotic hosts. By associating with putative hosts, a majority of the bacteria and archaea phyla were found to be infected by viruses. Viruses may influence prokaryotic ecological niches, and thus methanogenesis, by infecting key functional microorganisms, such as sulfate-reducing bacteria (SRB), syntrophic acetate-oxidizing bacteria (SAOB), and methanogens. Metabolic predictions for the viruses suggested that they may collaborate with hosts at key steps of sulfur and long-chain fatty acid (LCFA) metabolism and could be involved in typical methanogenesis pathways to participate in methane production. CONCLUSIONS Our results expanded the diversity of viruses in ADFW systems and suggested two ways that viral manipulated ADFW biochemical processes. Video Abstract.
Collapse
Affiliation(s)
- Lu Fan
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, 200092, China
| | - Wei Peng
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, 200092, China.
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
- Shanghai Engineering Research Center of Multi-Source Solid Wastes Co-processing and Energy Utilization, Shanghai, 200092, China.
| | - Haowen Duan
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, 200092, China
| | - Fan Lü
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China
- Shanghai Engineering Research Center of Multi-Source Solid Wastes Co-processing and Energy Utilization, Shanghai, 200092, China
| | - Hua Zhang
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China
- Shanghai Engineering Research Center of Multi-Source Solid Wastes Co-processing and Energy Utilization, Shanghai, 200092, China
| | - Pinjing He
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, 200092, China.
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
- Shanghai Engineering Research Center of Multi-Source Solid Wastes Co-processing and Energy Utilization, Shanghai, 200092, China.
| |
Collapse
|
5
|
Zhang M, Li K, Wang P, Gu W, Huang H, Xie B. Comparative insight into the effects of different carbon source supplement on antibiotic resistance genes during whole-run and short-cut nitrification-denitrification processes. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-27412-4. [PMID: 37249772 DOI: 10.1007/s11356-023-27412-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 04/30/2023] [Indexed: 05/31/2023]
Abstract
Mature landfill leachate is known for nitrogen-removal challenging and meantime was considered as an important sink of antibiotic resistance genes (ARGs). The added external carbon sources, enabling the short-cut nitrification and denitrification, may facilitate the proliferation of bacteria that possibly carry ARGs. However, this speculation has yet to be studied. Here, we explored the effects of glucose, sodium acetate, and methanol supplements on ARGs during whole-run and short-cut treatment processes. The results showed that sodium acetate supplement during short-cut process efficiently reduced the abundances of total ARGs (0.84-1.99 copies/16S rRNA) and integrons (0.59-1.20 copies/16S rRNA), which were highly enhanced by methanol addition during whole-run treatment process (total ARGs: 3.60-11.01 copies/16S rRNA, integrons: 1.20-4.69 copies/16S rRNA). Indirect gradient analysis showed that the variation of ARGs was not correlated with the supplement of different external carbon source. Correlation analysis indicated that dominant intl1 (55.99 ± 17.61% of integrons) showed positively significant correlations with all detected ARGs expect for sul2 and ermB (p < 0.05), suggesting the significant role on ARGs dissemination. Redundancy analysis illustrated that the potential hosts of intl1, intl2, sul1, tetQ, tetM, mefA, and mexF were dominant Bacteroidetes and Actinobacteria. Interestingly, the numbers and significant extent of correlations under the supplement of sodium acetate during short-cut denitrification process were obviously declined, and it was in accordance with ARGs reduced by sodium acetate supplement, suggesting sodium acetate displayed the efficient ARGs reduction during short-cut process. In summary, this study provides a comparative understanding of the effects on ARGs by different carbon source supplements during nitrification-denitrification processes of leachate; sodium acetate is the optimal carbon source.
Collapse
Affiliation(s)
- Meilan Zhang
- The State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, People's Republic of China
- Shanghai Laogang Waste Disposal Co., Shanghai, 201302, People's Republic of China
- Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, People's Republic of China
| | - Kaiyi Li
- Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, People's Republic of China
| | - Panliang Wang
- Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, People's Republic of China
| | - Wenchao Gu
- Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, People's Republic of China
| | - Huang Huang
- Shanghai Laogang Waste Disposal Co., Shanghai, 201302, People's Republic of China
| | - Bing Xie
- Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, People's Republic of China.
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, People's Republic of China.
| |
Collapse
|
6
|
Duan H, He P, Zhang H, Shao L, Lü F. Metabolic Regulation of Mesophilic Methanosarcina barkeri to Ammonium Inhibition. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:8897-8907. [PMID: 35588324 DOI: 10.1021/acs.est.2c01212] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Undesirable ammonium concentrations can lead to unstable anaerobic digestion processes, and Methanosarcina spp. are the representative methanogens under inhibition. However, no known work seems to exist for directly exploring the detailed metabolic regulation of pure cultured representative Methanosarcina spp. to ammonium inhibition. We used transcriptomics and proteomics to profile the metabolic regulation of Methanosarcina barkeri to 1, 4, and 7 g N/L of total ammoniacal nitrogen (TAN), where free ammonia concentrations were between 1.5 and 36.1 mg N/L. At the initial stages of ammonium inhibition, the genes participating in the acquisition and assimilation of reduced nitrogen sources showed significant upregulation where the minimal fold change of gene transcription was about 2. Apart from nitrogen metabolism, the transcription of some genes in methanogenesis also significantly increased at the initial stages. For example, the genes encoding alternative heterodisulfide reductase subunits (HdrAB), energy-converting hydrogenase subunit (EchC), and methanophenazine-dependent hydrogenase subunits (VhtAC) were significantly upregulated by at least 2.05 times. For the element translocation at the initial stages, the genes participating in the uptake of ferrous iron, potassium ion, and molybdate were significantly upregulated with a minimal fold change of 2.10. As the cultivation proceeded, the gene encoding the cell division protein subunit (FtsH) was significantly upregulated by 13.0 times at 7 g N/L of TAN; meanwhile, an increment in OD600 was observed at the terminal sampling point of 7 g N/L of TAN. The present study explored the metabolic regulation of M. barkeri in stress response, protein synthesis, signal transduction, nitrogen metabolism, methanogenesis, and element translocation. The results would contribute to the understanding of the metabolic effects of ammonium inhibition on methanogens and have significant practical implication in inhibited anaerobic digestion.
Collapse
Affiliation(s)
- Haowen Duan
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China
| | - Pinjing He
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai 200092, China
- Shanghai Multi-Source Solid Waste Collaborative Treatment and Energy Engineering Technology Research Center, Shanghai 200092, China
| | - Hua Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Liming Shao
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai 200092, China
| | - Fan Lü
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| |
Collapse
|
7
|
Kavan Kumar V, Mahendiran R, Subramanian P, Karthikeyan S, Surendrakumar A. Optimization of inoculum to substrate ratio for enhanced methane yield from leather fleshings in a batch study. J INDIAN CHEM SOC 2022. [DOI: 10.1016/j.jics.2022.100384] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
8
|
Yan M, Zhu X, Treu L, Ravenni G, Campanaro S, Goonesekera EM, Ferrigno R, Jacobsen CS, Zervas A, Angelidaki I, Fotidis IA. Comprehensive evaluation of different strategies to recover methanogenic performance in ammonia-stressed reactors. BIORESOURCE TECHNOLOGY 2021; 336:125329. [PMID: 34052546 DOI: 10.1016/j.biortech.2021.125329] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/20/2021] [Accepted: 05/21/2021] [Indexed: 06/12/2023]
Abstract
In this study, strategies for recovery of ammonia-stressed AD reactors were attempted, by addition of preserved bioaugmentation consortium in gel (BioG), fresh consortium in liquid medium (BioL), woodchip biochar (BW), and straw biochar (BS). In comparison to control group with ammonia, effective treatments, i.e., BioG, BioL, BW and BS raised the maximum methane production rate by 77%, 23%, 35%, and 24%, respectively. BW possibly acted as interspecies electrical conduits for Direct Electron Transfer based on conductivity and SEM analysis. BioG facilitated slow release of bioaugmentation inocula from gel into the AD system, which protected them from a direct environmental shock. According to microbial analysis, both BioG, BioL and BW resulted in increased relative abundance of Methanothermobacter thermautotrophicus; and BS induced selective raise of Methanosarcina thermophila. The increase of methanogens via these strategies led to the faster recovery of the AD process.
Collapse
Affiliation(s)
- Miao Yan
- Department of Environmental Engineering, Technical University of Denmark, Building 115, Kgs. Lyngby DK-2800, Denmark
| | - Xinyu Zhu
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, Building 227, Kgs. Lyngby DK-2800, Denmark
| | - Laura Treu
- Department of Biology, University of Padova, Via U. Bassi 58/b, Padova 35121, Italy
| | - Giulia Ravenni
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, Building 313, Roskilde 4000, Denmark
| | - Stefano Campanaro
- Department of Biology, University of Padova, Via U. Bassi 58/b, Padova 35121, Italy
| | - Estelle Maria Goonesekera
- Department of Environmental Engineering, Technical University of Denmark, Building 115, Kgs. Lyngby DK-2800, Denmark
| | - Rosa Ferrigno
- Department of Environmental Engineering, Technical University of Denmark, Building 115, Kgs. Lyngby DK-2800, Denmark
| | - Carsten S Jacobsen
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, Roskilde DK-4000, Denmark
| | - Athanasios Zervas
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, Roskilde DK-4000, Denmark
| | - Irini Angelidaki
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, Building 227, Kgs. Lyngby DK-2800, Denmark
| | - Ioannis A Fotidis
- Department of Environmental Engineering, Technical University of Denmark, Building 115, Kgs. Lyngby DK-2800, Denmark; Faculty of Engineering and Natural Sciences, Tampere University, Tampere, Finland; School of Civil Engineering Southeast University Nanjing, 210096, China.
| |
Collapse
|
9
|
Lee J, Kim E, Hwang S. Effects of inhibitions by sodium ion and ammonia and different inocula on acetate-utilizing methanogenesis: Methanogenic activity and succession of methanogens. BIORESOURCE TECHNOLOGY 2021; 334:125202. [PMID: 33957457 DOI: 10.1016/j.biortech.2021.125202] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 04/15/2021] [Accepted: 04/16/2021] [Indexed: 06/12/2023]
Abstract
Acetate-fed anaerobic sequential batch experiments with four different inhibitory conditions (non-inhibitory (Lo), sodium-ion inhibitory (Na), ammonia inhibitory (Am), combined inhibitory (Hi)) were conducted using thirteen different inocula to investigate the inhibition effects by sodium-ion and ammonia and different inocula on acetate-utilizing methanogenesis and succession of methanogens. Sodium-ion and ammonia significantly extended lag-time λ and reduced specific-methanogenic-activity RCH4, and caused synergistic inhibition. The inhibition differed according to the initial methanogen community structures: the inhibition effects on λ and RCH4 were strongest ininocula with Methanosaeta concilii dominant and weakest in inocula with Methanoculleus bourgensis dominant. These inhibitory conditions determined the succession of methanogens: the most competitive methanogens were Methanosaeta concilii in Lo, Methanosarcina sp. in Na, Methanosarcina sp. and Methanoculleus bourgensis in Am, Methanoculleus bourgensis in Hi. This study provides valuable information for microbial management and optimization for AD processes treating wastewater that is rich in protein and/or salt.
Collapse
Affiliation(s)
- Joonyeob Lee
- Department of Environmental Engineering, Pukyong National University, Busan 48513, Republic of Korea
| | - Eunji Kim
- Division of Environmental Science and Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Seokhwan Hwang
- Division of Environmental Science and Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea.
| |
Collapse
|
10
|
Zhao R, Liu J, Feng J, Li X, Li B. Microbial community composition and metabolic functions in landfill leachate from different landfills of China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 767:144861. [PMID: 33422962 DOI: 10.1016/j.scitotenv.2020.144861] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 12/24/2020] [Accepted: 12/25/2020] [Indexed: 06/12/2023]
Abstract
Landfill leachate usually harbors complex microbial communities responsible for the decomposition of municipal solid waste. However, the diversity and metabolic functions of the microbial communities in landfill leachate as well as the factors that influence them are still not well understood. In this study, Illumina MiSeq high-throughput sequencing was used to investigate the microbial community composition and metabolic functions in landfill leachate from 11 cities in China. The microbial diversity and structure of different leachate samples exhibited obvious differences. In general, Bacteroidetes, Firmicutes and Proteobacteria were the three dominant microbial communities among the 26 bacterial phyla identified in landfill leachate, regardless of the geographical locations. Diverse bacterial genera associated with various functions such as cellulolytic bacteria (e.g., Sphaerochaeta and Defluviitoga), acidifying bacteria (e.g., Prevotella and Trichococcus) and sulfate-reducing bacteria (e.g., Desulfuromonas and Desulfobacterium) were detected abundantly in the landfill leachate. Moreover, the archaeal community in all leachate samples was dominated by the orders Methanomicrobiales and Methanosarcinales belonging to the Euryarchaeota phylum. Notably, the archaea-specific primer pair covered more diverse archaeal communities than the universal bacteria-archaea primer pair. Seventeen archaeal genera belonging to acetoclastic, hydrogenotrophic, and methylotrophic methanogens were identified, and the composition of the dominant genera in these samples varied greatly. The canonical correlation analysis indicated that landfill age, electrical conductivity, ammonia nitrogen, and total nitrogen were significantly correlated with the microbial community structure. Based on PICRUSt2, a total of 41 metabolic pathways belonging to six metabolic pathway groups were predicted, and the KEGG pathway Metabolism was the most abundant group across all leachate samples. This study provides an important insight into the composition and functional characteristics of the microbial communities in landfill leachate.
Collapse
Affiliation(s)
- Renxin Zhao
- Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; Shenzhen Engineering Research Laboratory for Sludge and Food Waste Treatment and Resource Recovery, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Jie Liu
- Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; State Key Laboratory of Grassland Agro-ecosystems, Center for Grassland Microbiome, Lanzhou University, Lanzhou 730000, China
| | - Jie Feng
- Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; State Environmental Protection Key Laboratory of Drinking Water Source Management and Technology, Shenzhen Research Academy of Environmental Sciences, Shenzhen 518001, China
| | - Xiaoyan Li
- Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; Shenzhen Engineering Research Laboratory for Sludge and Food Waste Treatment and Resource Recovery, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; Shenzhen Environmental Science and New Energy Laboratory, Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518055, China
| | - Bing Li
- Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; Shenzhen Engineering Research Laboratory for Sludge and Food Waste Treatment and Resource Recovery, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China.
| |
Collapse
|
11
|
Cai Y, Zheng Z, Wang X. Obstacles faced by methanogenic archaea originating from substrate-driven toxicants in anaerobic digestion. JOURNAL OF HAZARDOUS MATERIALS 2021; 403:123938. [PMID: 33264986 DOI: 10.1016/j.jhazmat.2020.123938] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 09/01/2020] [Accepted: 09/02/2020] [Indexed: 06/12/2023]
Abstract
Anaerobic digestion (AD) is used to treat waste and produce bioenergy. However, toxicants, which originate from the substrate, can inhibit or damage the digestion process. Methanogenic archaea (MA), which are the executor in the methanogenesis stage, are more sensitive than bacteria to these toxicants. This review discusses the effects of substrate-driven toxicants, namely, antibiotics, H2S and sulfate, heavy metals (HMs), long-chain fatty acids (LCFAs), and ammonia nitrogen, on the activity of MAs, methanogenic pathways, and the inter-genus succession of MAs. The adverse effects of these five toxicants on MA include effects on pH, damages to cell membranes, the prevention of protein synthesis, changes in hydrogen partial pressure, a reduction in the bioavailability of trace elements, and hindrance of mass transfer. These effects cause a reduction in MA activity and the succession of MAs and methanogenic pathways, which affect AD performance. Under the stress of these toxicants, succession occurs among HA (hydrogenotrophic methanogen), AA (acetoclastic methanogen), and MM (methylotrophic methanogen), especially HA gradually replaces AA as the dominant MA. Simultaneously, the dominant methanogenic pathway also changes from the aceticlastic pathway to other methanogenic pathways. A comprehensive understanding of the impact of toxicants on MA permits more specific targeting when developing strategies to mitigate or eliminate the effects of these toxicants.
Collapse
Affiliation(s)
- Yafan Cai
- College of Agronomy and Biotechnology/Biomass Engineering Center, China Agricultural University, Beijing 100193, China; Department of Biochemical conversion, Deutsches Biomassforschungszentrum gemeinnütziges GmbH, Torgauer Straße116, 04347 Leipzig, Germany
| | - Zehui Zheng
- College of Agronomy and Biotechnology/Biomass Engineering Center, China Agricultural University, Beijing 100193, China
| | - Xiaofen Wang
- College of Agronomy and Biotechnology/Biomass Engineering Center, China Agricultural University, Beijing 100193, China.
| |
Collapse
|
12
|
Lagoa-Costa B, Kennes C, Veiga MC. Cheese whey fermentation into volatile fatty acids in an anaerobic sequencing batch reactor. BIORESOURCE TECHNOLOGY 2020; 308:123226. [PMID: 32251864 DOI: 10.1016/j.biortech.2020.123226] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/16/2020] [Accepted: 03/19/2020] [Indexed: 06/11/2023]
Abstract
The present research explored the optimization of volatile fatty acids (VFA) production from cheese whey in an anaerobic sequencing batch reactor (AnSBR). For that purpose, changes of solid and hydraulic retention times (SRT and HRT) were applied. Moreover, the experiments were coupled to metagenomic analyses by 16S rRNA sequencing. The results showed an enhancement of the process effectiveness at longer SRT and shorter HRT. The degree of acidification (DA) improved from 0.73 to 0.83 when increasing the SRT from 5 to 15 days. It also increased from 0.79 to 0.83 when lowering the HRT from 3 to 1 day. The acidification yield (YVFA/S) improved from 0.78 to 0.87 and from 0.86 to 0.90 g COD-VFA g COD-Lactose-1 when increasing the SRT from 5 to 15 days and decreasing the HRT from 3 to 1 day, respectively. Hydrolytic bacteria dominated the microbial community at the shortest SRT, although they were replaced by acidogenic bacteria at longer SRT.
Collapse
Affiliation(s)
- Borja Lagoa-Costa
- Chemical Engineering Laboratory, Faculty of Sciences and Centre for Advanced Scientific Research (CICA), University of A Coruña, Rúa da Fraga 10, E - 15008 A Coruña, Spain
| | - Christian Kennes
- Chemical Engineering Laboratory, Faculty of Sciences and Centre for Advanced Scientific Research (CICA), University of A Coruña, Rúa da Fraga 10, E - 15008 A Coruña, Spain
| | - María C Veiga
- Chemical Engineering Laboratory, Faculty of Sciences and Centre for Advanced Scientific Research (CICA), University of A Coruña, Rúa da Fraga 10, E - 15008 A Coruña, Spain.
| |
Collapse
|
13
|
Tian H, Yan M, Treu L, Angelidaki I, Fotidis IA. Hydrogenotrophic methanogens are the key for a successful bioaugmentation to alleviate ammonia inhibition in thermophilic anaerobic digesters. BIORESOURCE TECHNOLOGY 2019; 293:122070. [PMID: 31491648 DOI: 10.1016/j.biortech.2019.122070] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 08/20/2019] [Accepted: 08/24/2019] [Indexed: 05/20/2023]
Abstract
Bioaugmentation to alleviate ammonia inhibition under thermophilic anaerobic digestion has never been reported, as well as the working mechanism that allows a fast and successful bioaugmentation. Thus two bioaugmentation inocula (an enriched culture, and a mixed culture composed 50/50 by Methanoculleus thermophilus and the enriched culture) on the recovery of ammonia-inhibited thermophilic continuous reactors was assessed. The results showed that bioaugmentation improved methane yield by 11-13% and decreased the volatile fatty acids (VFA) by 45-52% compared to the control reactor (abiotic augmentation). Moreover, the importance of hydrogenotrophic methanogens to a fast and successful bioaugmentation was recognized. Specifically, the instant hydrogen partial pressure reduction by the bioaugmented hydrogenotroph created thermodynamically favourable conditions for the acetate oxidation process and consequently, the catabolism of other VFA. High-throughput sequencing results strengthened this explanation by showing that the bioaugmented M. thermophilus stimulated the growth of syntrophic acetate oxidising bacterium Thermacetogenium phaeum, immediately after bioaugmentation.
Collapse
Affiliation(s)
- Hailin Tian
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet Bygning 115, 2800 Kgs. Lyngby, Denmark; Environmental Research Institute, National University of Singapore, 1 Create Way, Create Tower, Singapore 138602, Singapore
| | - Miao Yan
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet Bygning 115, 2800 Kgs. Lyngby, Denmark
| | - Laura Treu
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet Bygning 115, 2800 Kgs. Lyngby, Denmark; Department of Biology, University of Padua, 35131 Padua, Italy
| | - Irini Angelidaki
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet Bygning 115, 2800 Kgs. Lyngby, Denmark
| | - Ioannis A Fotidis
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet Bygning 115, 2800 Kgs. Lyngby, Denmark.
| |
Collapse
|
14
|
Shi J, Han Y, Xu C, Han H. Enhanced biodegradation of coal gasification wastewater with anaerobic biofilm on polyurethane (PU), powdered activated carbon (PAC), and biochar. BIORESOURCE TECHNOLOGY 2019; 289:121487. [PMID: 31279321 DOI: 10.1016/j.biortech.2019.121487] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 05/11/2019] [Accepted: 05/13/2019] [Indexed: 06/09/2023]
Abstract
The primary objective was to explore the feasibility of anaerobic biofilm on polyurethane (PU), powdered activated carbon (PAC), and biochar in strengthening anaerobic degradation of phenolic compounds and selected nitrogen heterocyclic compounds (NHCs) in coal gasification wastewater (CGW). When total phenols (TPh) was less than 300 mg/L, PAC-based biofilm was more efficient. Whereas, when the TPh concentration was more than 450 mg/L, PU-based biofilm performed the optimal degradation efficiency. Furthermore, microbial community structure analysis showed that PAC and biochar had little effect on the microbial community structure after 120 days of operation, while the addition of PU could lead to the enrichment of Giesbergeria, Caldisericum, Thauera, Methanolinea, and Methanoregula.
Collapse
Affiliation(s)
- Jingxin Shi
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Yuxing Han
- School of Engineering, South China Agriculture University, Guangzhou 510642, China
| | - Chunyan Xu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Hongjun Han
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| |
Collapse
|
15
|
Gao M, Guo B, Zhang L, Zhang Y, Liu Y. Microbial community dynamics in anaerobic digesters treating conventional and vacuum toilet flushed blackwater. WATER RESEARCH 2019; 160:249-258. [PMID: 31152950 DOI: 10.1016/j.watres.2019.05.077] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 05/06/2019] [Accepted: 05/24/2019] [Indexed: 06/09/2023]
Abstract
Decentralized wastewater treatment represents a promising sustainable option for future wastewater management. Blackwater collected from toilets contains high concentrations of organic matter, ideal for energy recovery using anaerobic digestion. Up-flow anaerobic sludge blanket (UASB) reactors treating conventional toilet (CT, 9 L water per flush) and vacuum toilet (VT, 1 L water per flush) blackwater with increments of loadings were successfully operated to steady state in three phases. The organic loading rates were maintained at comparable levels between the two reactors. The methanisation rates were 0.23-0.29 and 0.41-0.48 gCH4-COD/gfeedCOD in the CT and VT reactors, and the COD removal rates were 72% and 89%, respectively. The enriched microbial consortia and the community dynamics under different loading phases were compared. The rank abundance distributions and alpha-diversity showed that archaeal communities were predominated by mono-enrichments in both CT and VT reactors, while bacterial communities showed lower diversity in the VT reactor. Through principal coordinates analysis (beta-diversity), clear divergences of archaeal and bacterial communities between the CT and VT reactors were revealed, and the archaeal community developed at a slower rate than the bacterial community. The enriched archaea were hydrogenotrophic methanogens, Methanolinea in the CT reactor (56.6%), and Methanogenium in the VT reactor (62.3%). The enriched bacteria were Porphyromonadaceae in both CT (15.9%) and VT (13.4%) reactors, sulfate-reducing bacteria in the CT reactor, and Fibrobacteraceae in the VT reactor (13.8%). Links between enriched consortia and ammonia stress were discussed. Isotope fraction analysis of the biogas showed a slight shift from acetoclastic methanogenesis to hydrogenotrophic methanogenesis. A closer look into the predicted metagenomic functional profiles showed agreeing results, where hydrogenotrophic methanogenesis and fhs gene abundances were higher in the VT reactor. We demonstrated that different blackwater types enriched different microbial consortia, probably due to ammonia concentrations and sulfate loadings, which should be taken into consideration for practical applications.
Collapse
Affiliation(s)
- Mengjiao Gao
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada
| | - Bing Guo
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada
| | - Lei Zhang
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada
| | - Yingdi Zhang
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada
| | - Yang Liu
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada.
| |
Collapse
|
16
|
Zheng M, Zhu H, Han Y, Xu C, Zhang Z, Han H. Comparative investigation on carbon-based moving bed biofilm reactor (MBBR) for synchronous removal of phenols and ammonia in treating coal pyrolysis wastewater at pilot-scale. BIORESOURCE TECHNOLOGY 2019; 288:121590. [PMID: 31195361 DOI: 10.1016/j.biortech.2019.121590] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 05/27/2019] [Accepted: 05/30/2019] [Indexed: 06/09/2023]
Abstract
By regulating the extraction solvent and alkali in pretreatment, two carbon-based MBBRs were compared in pilot-scale to synchronously remove phenols and ammonia of coal pyrolysis wastewater (CPW) under fluctuant phenols-ammonia loadings. It revealed that lignite activated coke (LAC)-based MBBR performed more stable with phenols increasing (250-550 mg/L), and reached higher tolerance limit to ammonia (>320 mg/L) than activated carbon (AC)-based MBBR under fluctuant ammonia loadings. During the phenols-ammonia synchronous removal process, the LAC provided the firm basis for shock resistance due to superior resilient adsorption capacity, enhanced sludge property and microbial cooperation. Furthermore, microbial analysis revealed that the strengthened collaboration between archaea and facultative bacteria played the primary role in phenols-ammonia synchronous degradation. Specifically, the heterotrophic bacteria consumed phenols-ammonia by partial nitrification process and ammonia assimilation, following by denitrifying process to further eliminate phenols. The multifunctional Comamonas was the critical genus participating in all procedures.
Collapse
Affiliation(s)
- Mengqi Zheng
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Hao Zhu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Yuxing Han
- School of Engineering, South China Agriculture University, Guangzhou 510642, China
| | - Chunyan Xu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Zhengwen Zhang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Hongjun Han
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| |
Collapse
|
17
|
Mahdy A, Wandera SM, Bi S, Song Y, Qiao W, Dong R. Response of the microbial community to the methanogenic performance of biologically hydrolyzed sewage sludge with variable hydraulic retention times. BIORESOURCE TECHNOLOGY 2019; 288:121581. [PMID: 31158775 DOI: 10.1016/j.biortech.2019.121581] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Revised: 05/26/2019] [Accepted: 05/27/2019] [Indexed: 06/09/2023]
Abstract
Hyperthermophilic biological hydrolysis of sewage sludge was applied before long-term anaerobic digestion to investigate how shortening hydraulic retention times (HRT, 20-5d) affected methanogenic performances and microbial dynamics. Results indicated that although the three different HRTs provided a stable process with a steady-state of methane production, both methane yield (161 L kg-VSin-1, 25% higher) and volatile solids removal (VS, 50%, 2-fold higher) increased during longer HRTs. Redundancy analysis results indicated that Sporosarcina and Methnosarcina positively correlated to VS removal and methane yield, and negatively correlated to volatile fatty acids (VFAs) accumulation. The relative abundance of Coprothermobacter (>60%), syntrophic acetate oxidation bacteria (SAOB), and Methanospirillum (8-15%), increased during shorter HRTs. A slight shift to two-stage acetate conversion was observed during shorter HRTs. The results demonstrated that HRTs played a key role in shaping microbial structure, leading to a new steady-state of microbial community profiles and process performances at variable HRTs.
Collapse
Affiliation(s)
- Ahmed Mahdy
- College of Engineering, China Agricultural University, Beijing 100083, China; Department of Agricultural Microbiology, Faculty of Agriculture, Zagazig University, 44511 Zagazig, Egypt
| | - Simon M Wandera
- College of Engineering, China Agricultural University, Beijing 100083, China
| | - Shaojie Bi
- College of Engineering, China Agricultural University, Beijing 100083, China; State R&D Center for Efficient Production and Comprehensive Utilization of Biobased Gaseous Fuels, Energy Authority, National Development, and Reform Committee, Beijing 100083, China
| | - Yunlong Song
- College of Engineering, China Agricultural University, Beijing 100083, China; State R&D Center for Efficient Production and Comprehensive Utilization of Biobased Gaseous Fuels, Energy Authority, National Development, and Reform Committee, Beijing 100083, China
| | - Wei Qiao
- College of Engineering, China Agricultural University, Beijing 100083, China; State R&D Center for Efficient Production and Comprehensive Utilization of Biobased Gaseous Fuels, Energy Authority, National Development, and Reform Committee, Beijing 100083, China
| | - Renjie Dong
- College of Engineering, China Agricultural University, Beijing 100083, China; State R&D Center for Efficient Production and Comprehensive Utilization of Biobased Gaseous Fuels, Energy Authority, National Development, and Reform Committee, Beijing 100083, China
| |
Collapse
|