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Tan Y, Xiao Y, Hao T. Carbon fixation via volatile fatty acids recovery from sewage sludge through electrochemical-pretreatment-based anaerobic digestion. WATER RESEARCH 2024; 258:121736. [PMID: 38754300 DOI: 10.1016/j.watres.2024.121736] [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: 03/12/2024] [Revised: 04/30/2024] [Accepted: 05/03/2024] [Indexed: 05/18/2024]
Abstract
Capturing the carbon in volatile fatty acids (VFA) produced from the anaerobic digestion (AD) of sewage sludge has the potential to not only provide economic benefits but also reduce greenhouse gas production. This study demonstrates a chemical-free method to collect VFA from an AD instead of methane that involves electrochemical pretreatment (EPT) of sludge. Experimental results show that applying 15 V EPT for 45 min enhances acidogenesis and selectively inhibits methanogenesis, leading to a substantial VFA accumulation (2563.1 ± 307.9 mg COD/L) and achieving 2.5 times more carbon fixation than via methane production. Interfacial thermodynamic analysis shows that EPT induces a decrease in both the repulsive electrostatic energy (from 152.9 kT to 12.2 kT) and the energy barrier (from 57.0 kT to 2.6 kT) in the sludge, leading to increased sludge aggregation and entrapment of microorganisms. Molecular docking sheds lights on how the methanogens interacts with the organic matter released from EPT (e.g., alanine-tRNA ligase), showing that these interactions potentially interfere with the proteins that are associated with the activities of the methanogens and the electron transfer pathways, thereby impeding methanogenesis. Integrating EPT into AD therefore facilitates the recovery of valuable VFA and the capture of carbon from freshwater sludge, providing notable economic and environmental benefits in sewage sludge treatment.
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Affiliation(s)
- Yunkai Tan
- Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau, PR China
| | - Yihang Xiao
- Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau, PR China
| | - Tianwei Hao
- Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau, PR China.
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Liu Y, Zhang Z, Song Y, Peng F, Feng Y. Long-term evaluating the strengthening effects of iron-carbon mediator for coking wastewater treatment in EGSB reactor. JOURNAL OF HAZARDOUS MATERIALS 2024; 474:134701. [PMID: 38824774 DOI: 10.1016/j.jhazmat.2024.134701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 05/05/2024] [Accepted: 05/21/2024] [Indexed: 06/04/2024]
Abstract
Coking wastewater (CWW) treatment is difficult due to its complex composition and high biological toxicity. Iron-carbon mediators was used to enhance the treatment of CWW through iron-carbon microelectrolysis (ICME). The results indicated that the removal rate of COD and phenolic compounds were enhanced by 24.1 % and 23.5 %, while biogas production and methane content were promoted by 50 % and 7 %. Microbial community analysis indicated that iron-carbon mediators had a transformative impact on the reactor's performance and dependability by enriching microorganisms involved in direct and indirect electron transfer, such as Anaerolineae and Methanothrix. The mediator also produced noteworthy gains in LB-EPS and TB-EPS, increasing by roughly 109.3 % and 211.6 %, respectively. PICRISt analysis demonstrated that iron-carbon mediators effectively augment the abundance of functional genes associated with metabolism, Citrate cycle, and EET pathway. This study provides a new approach for CWW treatment.
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Affiliation(s)
- Yanbo Liu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, No73, Huanghe Road, Nangang District, Harbin 150090, China
| | - Zhaohan Zhang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, No73, Huanghe Road, Nangang District, Harbin 150090, China.
| | - Yanfang Song
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, No73, Huanghe Road, Nangang District, Harbin 150090, China
| | - Fangyue Peng
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, No73, Huanghe Road, Nangang District, Harbin 150090, China
| | - Yujie Feng
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, No73, Huanghe Road, Nangang District, Harbin 150090, China
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Zhu X, Li P, Ju F. Microbiome dynamics and products profiles of biowaste fermentation under different organic loads and additives. Eng Life Sci 2024; 24:2300216. [PMID: 38708413 PMCID: PMC11065332 DOI: 10.1002/elsc.202300216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 08/26/2023] [Accepted: 10/05/2023] [Indexed: 05/07/2024] Open
Abstract
Biowaste fermentation is a promising technology for low-carbon print bioenergy and biochemical production. Although it is believed that the microbiome determines both the fermentation efficiency and the product profiles of biowastes, the explicit mechanisms of how microbial activity controls fermentation processes remained to be unexplored. The current study investigated the microbiome dynamics and fermentation product profiles of biowaste fermentation under different organic loads (5, 20, and 40 g-VS/L) and with additives that potentially modulate the fermentation process via methanogenesis inhibition (2-bromoethanesulfonate) or electron transfer promotion (i.e., reduced iron, magnetite iron, and activated carbon). The overall fermentation products yields were 440, 373 and 208 CH4-eq/g-VS for low-, medium- and high-load fermentation. For low- and medium-load fermentation, volatile fatty acids (VFAs) were first accumulated and were gradually converted to methane. For high-load fermentation, VFAs were the main fermentation products during the entire fermentation period, accounting for 62% of all products. 16S rRNA-based analyses showed that both 2-bromoethanesulfonate addition and increase of organic loads inhibited the activity of methanogens and promoted the activity of distinct VFA-producing bacterial microbiomes. Moreover, the addition of activated carbon promoted the activity of H2-producing Bacteroides, homoacetogenic Eubacteriaceae and methanogenic Methanosarcinaceae, whose activity dynamics during the fermentation led to changes in acetate and methane production. The current results unveiled mechanisms of microbiome activity dynamics shaping the biowaste fermentation product profiles and provided the fundamental basis for the development of microbiome-guided engineering approaches to modulate biowaste fermentation toward high-value product recovery.
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Affiliation(s)
- Xinyu Zhu
- Key Laboratory of Coastal Environment and Resources of Zhejiang ProvinceSchool of EngineeringWestlake UniversityHangzhouZhejiang ProvinceChina
- Environmental Microbiome and Biotechnology Laboratory, Center of Synthetic Biology and Integrated BioengineeringWestlake UniversityHangzhouZhejiang ProvinceChina
- Institute of Advanced TechnologyWestlake Institute for Advanced StudyHangzhouZhejiang ProvinceChina
- Westlake Laboratory of Life Sciences and BiomedicineHangzhouChina
| | - Ping Li
- Key Laboratory of Coastal Environment and Resources of Zhejiang ProvinceSchool of EngineeringWestlake UniversityHangzhouZhejiang ProvinceChina
- Environmental Microbiome and Biotechnology Laboratory, Center of Synthetic Biology and Integrated BioengineeringWestlake UniversityHangzhouZhejiang ProvinceChina
- Institute of Advanced TechnologyWestlake Institute for Advanced StudyHangzhouZhejiang ProvinceChina
| | - Feng Ju
- Key Laboratory of Coastal Environment and Resources of Zhejiang ProvinceSchool of EngineeringWestlake UniversityHangzhouZhejiang ProvinceChina
- Environmental Microbiome and Biotechnology Laboratory, Center of Synthetic Biology and Integrated BioengineeringWestlake UniversityHangzhouZhejiang ProvinceChina
- Institute of Advanced TechnologyWestlake Institute for Advanced StudyHangzhouZhejiang ProvinceChina
- Westlake Laboratory of Life Sciences and BiomedicineHangzhouChina
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Wang G, Fu P, Su Y, Zhang B, Zhang M, Li Q, Zhang J, Li YY, Chen R. Comparing the mechanisms of syntrophic volatile fatty acids oxidation and methanogenesis recovery from ammonia stress in regular and biochar-assisted anaerobic digestion: Different roads lead to the same goal. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 352:120041. [PMID: 38219669 DOI: 10.1016/j.jenvman.2024.120041] [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: 09/21/2023] [Revised: 12/19/2023] [Accepted: 12/25/2023] [Indexed: 01/16/2024]
Abstract
Biochar has been recognized as a promising additive to mitigate ammonia inhibition during syntrophic methanogenesis, while the key function of biochar in this process is still in debates. This study clarified the distinct mechanisms of syntrophic volatile fatty acids -oxidizing and methanogenesis recovery from ammonia inhibition in regular and biochar-assisted anaerobic digestion. Under 5 g/L ammonia stress, adding biochar shortened the methanogenic lag time by 10.9% and dramatically accelerated the maximum methane production rate from 60.3 to 94.7 mLCH4/gVSsludge/d. A photometric analysis with a nano-WO3 probe revealed that biochar enhanced the extracellular electron transfer (EET) capacity of suspended microbes (Pearson's r = -0.98), confirming that biochar facilitated methanogenesis by boosting EET between syntrophic butyrate oxidizer and methanogens. Same linear relationship between EET capacity and methanogenic rate was not observed in the control group. Microbial community integrating functional genes prediction analysis uncovered that biochar re-shaped syntrophic partners by enriching Constridium_sensu_stricto/Syntrophomonas and Methanosarcina. The functional genes encoding Co-enzyme F420 hydrogenase and formylmethanofuran dehydrogenase were upregulated by 1.4-2.3 times, consequently enhanced the CO2-reduction methanogenesis pathway. Meanwhile, the abundances of gene encoding methylene-tetrahydrofolate transformation, a series of intermediate processes involved in acetate oxidation, in the biochar-assisted group were 28.2-63.7% higher than these in control group. Comparatively, Methanosaeta played a pivotal role driving aceticlastic methanogenesis in the control group because the abundance of gene encoding acetyl-CoA decarbonylase/synthase complex increased by 1.9 times, suggesting an aceticlastic combining H2-based syntrophic methanogenesis pathway was established in control group to resist ammonia stress. A 2nd period experiment elucidated that although depending on distinct mechanisms, the volatile fatty acid oxidizers and methanogens in both groups developed sustained and stable strategies to resist ammonia stress. These findings provided new insights to understand the distinct methanogenic recovery strategy to resist toxic stress under varied environmental conditions.
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Affiliation(s)
- Gaojun Wang
- Key Lab of Environmental Engineering (Shaanxi Province), School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No.13 Yanta Road, Xi'an 710055, China; International S&T Cooperation Center for Urban Alternative Water Resources Development, Key Laboratory of Northwest Water Resource, Environment and Ecology (Ministry of Education), Xi'an University of Architecture and Technology, No.13 Yanta Road, Xi'an 710055, China
| | - Peng Fu
- Key Lab of Environmental Engineering (Shaanxi Province), School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No.13 Yanta Road, Xi'an 710055, China
| | - Yan Su
- Xi'an TPRI Water-Management & Environmental Protection Co. Ltd., State Key Laboratory of High-Efficiency Flexible Coal Power Generation and Carbon Capture Utilization and Storage, Xi'an 710054, China
| | - Bo Zhang
- Key Lab of Environmental Engineering (Shaanxi Province), School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No.13 Yanta Road, Xi'an 710055, China
| | - Mengyuan Zhang
- Key Lab of Environmental Engineering (Shaanxi Province), School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No.13 Yanta Road, Xi'an 710055, China
| | - Qian Li
- Key Lab of Environmental Engineering (Shaanxi Province), School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No.13 Yanta Road, Xi'an 710055, China; International S&T Cooperation Center for Urban Alternative Water Resources Development, Key Laboratory of Northwest Water Resource, Environment and Ecology (Ministry of Education), Xi'an University of Architecture and Technology, No.13 Yanta Road, Xi'an 710055, China; Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi, 980-8579, Japan
| | - Jianfeng Zhang
- Key Lab of Environmental Engineering (Shaanxi Province), School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No.13 Yanta Road, Xi'an 710055, China
| | - Yu-You Li
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi, 980-8579, Japan
| | - Rong Chen
- Key Lab of Environmental Engineering (Shaanxi Province), School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No.13 Yanta Road, Xi'an 710055, China; International S&T Cooperation Center for Urban Alternative Water Resources Development, Key Laboratory of Northwest Water Resource, Environment and Ecology (Ministry of Education), Xi'an University of Architecture and Technology, No.13 Yanta Road, Xi'an 710055, China.
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