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Lin C, Liang H, Yang X, Zhan J, Yang Q. Voltage recovery from frozen microbial fuel cells in the laboratory and outdoor field reactors. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 942:173751. [PMID: 38839000 DOI: 10.1016/j.scitotenv.2024.173751] [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: 02/28/2024] [Revised: 05/21/2024] [Accepted: 06/02/2024] [Indexed: 06/07/2024]
Abstract
Extreme temperature variations are a problem that must be faced in the practical application of microbial fuel cells (MFCs), but MFCs are not extensively described for low and even freezing temperatures. This study assessed the effect of low-temperature shock on the power generation performance and microbial community structure of MFCs. Two scales of MFCs, the small (mL-MFC) and the large (L-MFC), were constructed in the laboratory and their performance was evaluated before and after freezing at -18 °C. The experimental results demonstrate that both MFCs were capable of rapidly restoring their voltage to the previous level after thawing. For the mL-MFC (rGO/Ag), the power density recovered from 194.30 ± 10.84 mW/m2 to 195.57 ± 4.02 mW/m2 after thawing. For L-MFC (carbon felt electrodes), the power density increased significantly from the initial 1.79 mW/m2 to 173.90 mW/m2 after thawing, but the performance degradation problem after reactor amplification still needs to be solved. The sediment microbial fuel cell (SMFC) was successfully constructed and operated in a natural outdoor environment to maintain high voltage output after the period of frost. Microbial analysis indicated after the frost period, psychrotolerant microorganisms enriched on the anode, such as Flavobacterium and Psychrobacter, while the relative abundance of anaerobic methanogenic bacterium decreased. Overall, freeze-thaw operations had a non-negative impact on the performance of MFCs and provided some references for their practical applications.
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Affiliation(s)
- Chunyang Lin
- School of Chemical Engineering, Ocean and Life Sciences, Dalian University of Technology, Panjin 124221, China
| | - Haoran Liang
- School of Chemical Engineering, Ocean and Life Sciences, Dalian University of Technology, Panjin 124221, China
| | - Xiaojing Yang
- School of Chemical Engineering, Ocean and Life Sciences, Dalian University of Technology, Panjin 124221, China
| | - Jingjing Zhan
- School of Chemical Engineering, Ocean and Life Sciences, Dalian University of Technology, Panjin 124221, China
| | - Qiao Yang
- School of Chemical Engineering, Ocean and Life Sciences, Dalian University of Technology, Panjin 124221, China.
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2
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Chen A, Li H, Wu H, Song Z, Chen Y, Zhang H, Pang Z, Qin Z, Wu Y, Guan X, Huang H, Li Z, Qiu G, Wei C. Anaerobic cyanides oxidation with bimetallic modulation of biological toxicity and activity for nitrite reduction. JOURNAL OF HAZARDOUS MATERIALS 2024; 472:134540. [PMID: 38733787 DOI: 10.1016/j.jhazmat.2024.134540] [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: 02/29/2024] [Revised: 04/26/2024] [Accepted: 05/03/2024] [Indexed: 05/13/2024]
Abstract
Cyanide is a typical toxic reducing agent prevailing in wastewater with a well-defined chemical mechanism, whereas its exploitation as an electron donor by microorganisms is currently understudied. Given that conventional denitrification requires additional electron donors, the cyanide and nitrogen can be eliminated simultaneously if the reducing HCN/CN- and its complexes are used as inorganic electron donors. Hence, this paper proposes anaerobic cyanides oxidation for nitrite reduction, whereby the biological toxicity and activity of cyanides are modulated by bimetallics. Performance tests illustrated that low toxicity equivalents of iron-copper composite cyanides provided higher denitrification loads with the release of cyanide ions and electrons from the complex structure by the bimetal. Both isotopic labeling and Density Functional Theory (DFT) demonstrated that CN--N supplied electrons for nitrite reduction. The superposition of chemical processes reduces the biotoxicity and enhances the biological activity of cyanides in the CN-/Fe3+/Cu2+/NO2- coexistence system, including complex detoxification of CN- by Fe3+, CN- release by Cu2+ from [Fe(CN)6]3-, and NO release by nitrite substitution of -CN groups. Cyanide is the smallest structural unit of C/N-containing compounds and serves as a probe to extend the electron-donating principle of anaerobic cyanides oxidation to more electron-donor microbial utilization.
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Affiliation(s)
- Acong Chen
- School of Environment and Energy, South China University of Technology, Guangzhou, Guangdong 510006, PR China
| | - Haoling Li
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, Guangdong 510006, PR China
| | - Haizhen Wu
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, Guangdong 510006, PR China.
| | - Zhaohui Song
- School of Environment and Energy, South China University of Technology, Guangzhou, Guangdong 510006, PR China
| | - Yao Chen
- School of Environment and Energy, South China University of Technology, Guangzhou, Guangdong 510006, PR China
| | - Heng Zhang
- School of Environment and Energy, South China University of Technology, Guangzhou, Guangdong 510006, PR China
| | - Zijun Pang
- School of Environment and Energy, South China University of Technology, Guangzhou, Guangdong 510006, PR China
| | - Zhi Qin
- School of Environment and Energy, South China University of Technology, Guangzhou, Guangdong 510006, PR China
| | - Yulun Wu
- School of Environment and Energy, South China University of Technology, Guangzhou, Guangdong 510006, PR China
| | - Xianghong Guan
- School of Environment and Energy, South China University of Technology, Guangzhou, Guangdong 510006, PR China
| | - Hua Huang
- School of Environment and Energy, South China University of Technology, Guangzhou, Guangdong 510006, PR China
| | - Zemin Li
- School of Environment and Energy, South China University of Technology, Guangzhou, Guangdong 510006, PR China; School of Environment, South China Normal University, Guangzhou, Guangdong 510006, PR China
| | - Guanglei Qiu
- School of Environment and Energy, South China University of Technology, Guangzhou, Guangdong 510006, PR China
| | - Chaohai Wei
- School of Environment and Energy, South China University of Technology, Guangzhou, Guangdong 510006, PR China; School of Environment and Energy, Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, South China University of Technology, Guangzhou, Guangdong 510006, PR China.
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Gao M, Guo B, Zou X, Guo H, Yao Y, Chen Y, Guo J, Liu Y. Mechanisms of anammox granular sludge reactor effluent as biostimulant: Shaping microenvironment for anammox metabolism. BIORESOURCE TECHNOLOGY 2024; 406:130962. [PMID: 38876278 DOI: 10.1016/j.biortech.2024.130962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 06/01/2024] [Accepted: 06/11/2024] [Indexed: 06/16/2024]
Abstract
Effluent from anammox granular sludge (AnGS) bioreactor contains microbes and microbial products. This study explored mechanisms of utilizing AnGS-effluent as biostimulant for anammox process enhancement. Compared with no AnGS-effluent supplemented control reactor, 5.0 and 1.3 times higher ammonium nitrogen and total inorganic nitrogen removal rates, respectively were obtained with continuous AnGS-effluent supplementation after 98 days' operation. Anammox bacteria from Candidatus Brocadia accounted for 0.1 % (DNA level) and 1.3 %-1.5 % (RNA level) in control reactor, and 2.9 % (DNA level) and 54.5 %-55.4 % (RNA level) in the AnGS-effluent-fed reactor. Influent microbial immigration evaluation showed that bacterial immigration via AnGS-effluent supplementation was not the main contributor to active anammox community development. Amino acids biosynthesis, B-vitamins and coenzymes metabolism related pathways were facilitated by AnGS-effluent supplementation. AnGS-effluent supplementation aided anammox metabolic activity by shaping microenvironment and microbial interactions. This study provides insights into enhancing anammox bacterial metabolism with AnGS-effluent microbial products as biostimulant.
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Affiliation(s)
- Mengjiao Gao
- College of Environment and Ecology, Chongqing University, Chongqing 400044, China; Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Bing Guo
- Centre for Environmental Health and Engineering (CEHE), School of Sustainability, Civil and Environmental Engineering, University of Surrey, Guildford GU2 7XH, UK
| | - Xin Zou
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada; School of Civil & Environmental Engineering, Queensland University of Technology, Brisbane QLD 4001, Queensland, Australia
| | - Hengbo Guo
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Yiduo Yao
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Youpeng Chen
- College of Environment and Ecology, Chongqing University, Chongqing 400044, China
| | - Jinsong Guo
- College of Environment and Ecology, Chongqing University, Chongqing 400044, China
| | - Yang Liu
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada; School of Civil & Environmental Engineering, Queensland University of Technology, Brisbane QLD 4001, Queensland, Australia.
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Wang H, Zhou Q. Potential application of bioelectrochemical systems in cold environments. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 927:172385. [PMID: 38604354 DOI: 10.1016/j.scitotenv.2024.172385] [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: 02/06/2024] [Revised: 03/17/2024] [Accepted: 04/08/2024] [Indexed: 04/13/2024]
Abstract
Globally, more than half of the world's regions and populations inhabit psychrophilic and seasonally cold environments. Lower temperatures can inhibit the metabolic activity of microorganisms, thereby restricting the application of traditional biological treatment technologies. Bioelectrochemical systems (BES), which combine electrochemistry and biocatalysis, can enhance the resistance of microorganisms to unfavorable environments through electrical stimulation, thus showing promising applications in low-temperature environments. In this review, we focus on the potential application of BES in such environments, given the relatively limited research in this area due to temperature limitations. We select microbial fuel cells (MFC), microbial electrolytic cells (MEC), and microbial electrosynthesis cells (MES) as the objects of analysis and compare their operational mechanisms and application fields. MFC mainly utilizes the redox potential of microorganisms during substance metabolism to generate electricity, while MEC and MES promote the degradation of refractory substances by augmenting the electrode potential with an applied voltage. Subsequently, we summarize and discuss the application of these three types of BES in low-temperature environments. MFC can be employed for environmental remediation as well as for biosensors to monitor environmental quality, while MEC and MES are primarily intended for hydrogen and methane production. Additionally, we explore the influencing factors for the application of BES in low-temperature environments, including operational parameters, electrodes and membranes, external voltage, oxygen intervention, and reaction devices. Finally, the technical, economic, and environmental feasibility analyses reveal that the application of BES in low-temperature environments has great potential for development.
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Affiliation(s)
- Hui Wang
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Qixing Zhou
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
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5
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Feng K, Lu Y, Zhou W, Xu Z, Ye J, Zhang S, Chen J, Zhao J. Metagenomics revealing biomolecular insights into the enhanced toluene removal and electricity generation in PANI@CNT bioanode. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 927:172402. [PMID: 38608888 DOI: 10.1016/j.scitotenv.2024.172402] [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: 02/04/2024] [Revised: 03/28/2024] [Accepted: 04/09/2024] [Indexed: 04/14/2024]
Abstract
Microbial fuel cells (MFCs) have significant potential for environmental remediation and energy recycling directly from refractory aromatic hydrocarbons. To boost the capacities of toluene removal and the electricity production in MFCs, this study constructed a polyaniline@carbon nanotube (PANI@CNT) bioanode with a three-dimensional framework structure. Compared with the control bioanode based on graphite sheet, the PANI@CNT bioanode increased the output voltage and toluene degradation kinetics by 2.27-fold and 1.40-fold to 0.399 V and 0.60 h-1, respectively. Metagenomic analysis revealed that the PANI@CNT bioanode promoted the selective enrichment of Pseudomonas, with the dual functions of degrading toluene and generating exogenous electrons. Additionally, compelling genomic evidence elucidating the relationship between functional genes and microorganisms was found. It was interesting that the genes derived from Pseudomonas related to extracellular electron transfer, tricarboxylic acid cycle, and toluene degradation were upregulated due to the existence of PANI@CNT. This study provided biomolecular insights into key genes and related microorganisms that effectively facilitated the organic pollutant degradation and energy recovery in MFCs, offering a novel alternative for high-performance bioanode.
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Affiliation(s)
- Ke Feng
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Yi Lu
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Weikang Zhou
- Zhejiang Engineering Survey and Design Institute Group Co., Ltd., Ningbo 315012, China
| | - Zijiong Xu
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jiexu Ye
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Shihan Zhang
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jianmeng Chen
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jingkai Zhao
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.
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6
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Cheng S, Li H, He X, Chen H, Li L. Improving anammox activity and reactor start-up speed by using CO 2/NaHCO 3 buffer. J Environ Sci (China) 2024; 139:60-71. [PMID: 38105078 DOI: 10.1016/j.jes.2023.05.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/28/2023] [Accepted: 05/12/2023] [Indexed: 12/19/2023]
Abstract
Anammox bacteria grow slowly and can be affected by large pH fluctuations. Using suitable buffers could make the start-up of anammox reactors easy and rapid. In this study, the effects of three kinds of buffers on the nitrogen removal and growth characteristics of anammox sludge were investigated. Reactors with CO2/NaHCO3 buffer solution (CCBS) performed the best in nitrogen removal, while 4-(2-hydroxyerhyl)piperazine-1-ethanesulfonic acid (HEPES) and phosphate buffer solution (PBS) inhibited the anammox activity. Reactors with 50 mmol/L CCBS could start up in 20 days, showing the specific anammox activity and anammox activity of 1.01±0.10 gN/(gVSS·day) and 0.83±0.06 kgN/(m3·day), respectively. Candidatus Kuenenia was the dominant anammox bacteria, with a relative abundance of 71.8%. Notably, anammox reactors could also start quickly by using 50 mmol/L CCBS under non-strict anaerobic conditions. These findings are meaningful for the quick start-up of engineered anammox reactors and prompt enrichment of anammox bacteria.
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Affiliation(s)
- Shaoan Cheng
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering, Zhejiang University, Hangzhou 310027, China.
| | - Huahua Li
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering, Zhejiang University, Hangzhou 310027, China
| | - Xinyuan He
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering, Zhejiang University, Hangzhou 310027, China
| | - Hua Chen
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering, Zhejiang University, Hangzhou 310027, China
| | - Longxin Li
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering, Zhejiang University, Hangzhou 310027, China
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7
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Zhao C, Jiao T, Zhang W, Zhang W, Jia M, Liu S, Zhang M, Han F, Han Y, Lei J, Wang X, Zhou W. Nutrients recovery by coupled bioreactor of heterotrophic ammonia assimilation and microbial fuel cell in saline wastewater. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 918:170697. [PMID: 38331272 DOI: 10.1016/j.scitotenv.2024.170697] [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: 11/22/2023] [Revised: 01/24/2024] [Accepted: 02/02/2024] [Indexed: 02/10/2024]
Abstract
Heterotrophic ammonia assimilation (HAA) process had been widely used in the treatment of high salt wastewater, but the electro enhanced coupling process and electron transfer process were rarely studied. In this study, a HAA process coupled microbial fuel cell (MFC) system was established to treat ammonia-containing wastewater under increasing salinity to achieve nitrogen recovery and electricity generation. Up to 95.4 % NH4+-N and 96.4 % COD removal efficiencies were achieved at 2 % salinity in HAA-MFC. The maximum power density and current density at 2 % salinity were 29.93 mW/m2 and 182.37 mA/m2, respectively. The residual organic matter in the cathode effluent was effectively removed by the anode. The increase of salinity not only enhanced the sludge settling performance and activity, but also promoted the enzyme activity and amino acid production of the ammonia assimilation pathway. Marinobacter and Halomonas were gradually enriched at the anode and cathode with increased salinity to promote ammonia assimilation and electron production. This research offered a promising solution to overcome salinity-related challenges in wastewater treatment and resource recovery.
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Affiliation(s)
- Chuanfu Zhao
- School of Civil Engineering, Shandong University, Jinan, Shandong, PR China; Laboratory of water-sediment regulation and eco-decontamination, Jinan, Shandong, PR China
| | - Tong Jiao
- School of Civil Engineering, Shandong University, Jinan, Shandong, PR China; Laboratory of water-sediment regulation and eco-decontamination, Jinan, Shandong, PR China
| | - Wenhao Zhang
- School of Civil Engineering, Shandong University, Jinan, Shandong, PR China; Laboratory of water-sediment regulation and eco-decontamination, Jinan, Shandong, PR China
| | - Wenchao Zhang
- School of Civil Engineering, Shandong University, Jinan, Shandong, PR China; Laboratory of water-sediment regulation and eco-decontamination, Jinan, Shandong, PR China
| | - Man Jia
- Shandong Provincial Eco-Environment Monitoring Center, Jinan, Shandong, PR China
| | - Sheng Liu
- School of Civil Engineering, Shandong University, Jinan, Shandong, PR China; Laboratory of water-sediment regulation and eco-decontamination, Jinan, Shandong, PR China
| | - Mengru Zhang
- School of Civil Engineering, Shandong University, Jinan, Shandong, PR China; Laboratory of water-sediment regulation and eco-decontamination, Jinan, Shandong, PR China
| | - Fei Han
- School of Civil Engineering, Shandong University, Jinan, Shandong, PR China; Laboratory of water-sediment regulation and eco-decontamination, Jinan, Shandong, PR China
| | - Yufei Han
- School of Civil Engineering, Shandong University, Jinan, Shandong, PR China; Laboratory of water-sediment regulation and eco-decontamination, Jinan, Shandong, PR China
| | - Jianhua Lei
- School of Civil Engineering, Shandong University, Jinan, Shandong, PR China; Laboratory of water-sediment regulation and eco-decontamination, Jinan, Shandong, PR China
| | - Xianfeng Wang
- Shandong Provincial Eco-Environment Monitoring Center, Jinan, Shandong, PR China.
| | - Weizhi Zhou
- School of Civil Engineering, Shandong University, Jinan, Shandong, PR China; Laboratory of water-sediment regulation and eco-decontamination, Jinan, Shandong, PR China.
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Zhang LH, Zhang J, Hu X. Analyzing the nitrogen removal performance and cold adaptation mechanism of immobilized cold-acclimation ANAMMOX granules at low temperatures. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2024; 96:e10985. [PMID: 38305068 DOI: 10.1002/wer.10985] [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: 12/15/2023] [Revised: 01/01/2024] [Accepted: 01/06/2024] [Indexed: 02/03/2024]
Abstract
To improve the treatment performance of anaerobic ammonium oxidation (ANAMMOX) processes at low temperatures, the immobilized cold-acclimation ANAMMOX granules (R3) were prepared and their low-temperature nitrogen removal ability as well as the cold adaptation mechanism were analyzed. The results indicated that the total inorganic nitrogen (TIN) removal efficiency of R3 was significantly higher than that of R2 (cold-acclimation granules without immobilization) and R1 (common granules), especially at 11 ± 2 and 7 ± 2°C (68% and 54%). These were attributed to the remarkable biomass retention capacity of R3, high up to 4.3-4.9 mg/gVSS even at 5-18°C. Besides, higher protein (PN) content of tightly bound extracellular polymeric substances (TB-EPS) also facilitated microbial aggregation in R3. Meanwhile, R3 granules retained higher ANAMMOX activity and heme c content at 5-25°C. The original dominant ANAMMOX genus (Candidatus Kuenenia) in R3 kept higher abundance (49%-57%) at 23 ± 2 and 16 ± 2°C, whereas Candidatus Brocadia became the dominant ANAMMOX genus (25%-32%) in R3 at 11 ± 2 and 7 ± 2°C. Notably, different ANAMMOX genera in R3 may adapt to cold environment by regulating the expression of cold-stress proteins (CspA, CspB, PpiD, and UspA). PRACTITIONER POINTS: Immobilized cold-acclimation ANAMMOX granules showed higher nitrogen removal efficiency at 23°C → 5°C. Immobilization method effectively retained biomass (Candidatus Kuenenia and Candidatus Brocadia). Immobilization facilitated TB-EPS release and biological aggregation in cold-acclimation granules. Expression of cold-stress proteins in immobilized cold-acclimation granules was more active.
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Affiliation(s)
- Lin-Hua Zhang
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, China
- College of Civil and Architectural Engineering, Hebei Key Laboratory of Earthquake Engineering and Disaster Prevention, North China University of Science and Technology, Tangshan, China
| | - Jing Zhang
- College of Civil and Architectural Engineering, Hebei Key Laboratory of Earthquake Engineering and Disaster Prevention, North China University of Science and Technology, Tangshan, China
| | - Xiang Hu
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, China
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Wang H, Zeng S, Luo L, Xu Y, Yasuo I, Luo F. Metatranscriptome revealed how carbon brush addition affected the fermentation of food wastewater in the low-temperature environment. ENVIRONMENTAL RESEARCH 2023; 239:117382. [PMID: 37832774 DOI: 10.1016/j.envres.2023.117382] [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: 07/01/2023] [Revised: 09/05/2023] [Accepted: 10/10/2023] [Indexed: 10/15/2023]
Abstract
Improving the anaerobic digestion (AD) performance in low-temperature environments has become a key factor in the development of waste treatment and resource recovery in cold regions. The utilization of external carriers to form a biofilm is the simplest and most practical way to enhance the psychrophilic AD performance in cold regions. In this study, the effect of carrier addition on the fermentation performance of low-temperature (15 ± 2 °C) food wastewater was investigated by forming biofilms with carbon brushes. The results showed that although the biofilm formation enhanced methane yields (15.24%), it also caused more accumulation of propionic acid (306.99-626.89 mg/L), and the concentration of acetic acid (86.78-254.71 mg/L) was relatively low. The microbial community revealed the highest abundance of the fermentative bacterium Firmicutes and the carbon brush carrier significantly increased its relative abundance (23.74%). Metatranscriptomic sequencing revealed that the abundance level of Clostridium, Bacteroides, Sedimentibacter and Pelotomaculum was the highest, reaching 80% in all groups. In addition, the abundance level of electroactive microorganisms in biofilms was higher, while the fermentation bacteria and methanogens were lower. This showed that biofilm can enrich more electroactive microorganisms, and granular sludge needs to enrich more fermentation bacteria and methanogens to ensure metabolic activity. Further studies have found that carbon metabolism had the highest activity (27.86%-30.39%) and H+-transporting ATPase (atp) was the most dominant functional enzyme (85.50%-86.65%) involved in electron transport in low-temperature fermentation of food wastewater. Interestingly, these expression levels of active granular sludge were higher than the biofilm formed by carbon brushes. Meanwhile, analysis of the methanogenic pathway found that active granular sludge tends to be directly metabolized to realize acetate to acetyl-CoA by acetyl-CoA synthetase (ACSS), while biofilms were not significantly different in the two metabolic pathways of acetate. These results deepen the understanding of treating low-temperature food wastewater.
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Affiliation(s)
- Hui Wang
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
| | - Shufang Zeng
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
| | - Lijun Luo
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
| | - Yan Xu
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
| | - Igarashi Yasuo
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
| | - Feng Luo
- College of Resources and Environment, Southwest University, Chongqing, 400715, China.
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10
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Zhao C, Chen H, Song Y, Zhu L, Ai T, Wang X, Liu Z, Wei X. Electricity production performance enhancement of microbial fuel cells with double-layer sodium alginate hydrogel bioanodes driven by high-salinity waste leachate. WATER RESEARCH 2023; 242:120281. [PMID: 37422979 DOI: 10.1016/j.watres.2023.120281] [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: 04/20/2023] [Revised: 06/21/2023] [Accepted: 06/27/2023] [Indexed: 07/11/2023]
Abstract
The poor bacterial loading capacity and biocompatibility of the anode lead to weak electricity production performance of microbial fuel cells (MFCs). Inspired by kelp, we developed a double-layer hydrogel bioanode based on sodium alginate (SA). The inner hydrogel layer of encapsulated Fe3O4 and electroactive microorganisms (EAMs) was used as the bioelectrochemical catalytic layer. The outer hydrogel layer formed by cross-linking SA with polyvinyl alcohol (PVA) was used as the protective layer. The 3D porous structure of the inner hydrogel formed based on Fe3O4 facilitated the electroactive bacteria colonization and electron transfer, while the high structural toughness, salt-resistance and antibacterial properties of the outer highly cross-linked hydrogel served to protect the catalytic layer for stable electricity production. When high-salt waste leachate was used as the nutrient, the amazing open-circuit voltage (OCV) of 1.17 V and the operating voltage of 781 mV were brought by the double-layer hydrogel bioanode PVA@SA&Fe3O4/EAMs@SA.
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Affiliation(s)
- Chao Zhao
- Hebei Key Laboratory of Low Carbon and High Efficiency Power Generation Technology, North China Electric Power University, Baoding, Hebei Province, 071003, China
| | - Hongwei Chen
- Hebei Key Laboratory of Low Carbon and High Efficiency Power Generation Technology, North China Electric Power University, Baoding, Hebei Province, 071003, China
| | - Yangfan Song
- Hebei Key Laboratory of Low Carbon and High Efficiency Power Generation Technology, North China Electric Power University, Baoding, Hebei Province, 071003, China.
| | - Lou Zhu
- Hebei Key Laboratory of Low Carbon and High Efficiency Power Generation Technology, North China Electric Power University, Baoding, Hebei Province, 071003, China
| | - Tianchao Ai
- Hebei Key Laboratory of Low Carbon and High Efficiency Power Generation Technology, North China Electric Power University, Baoding, Hebei Province, 071003, China
| | - Xinxin Wang
- Hebei Key Laboratory of Low Carbon and High Efficiency Power Generation Technology, North China Electric Power University, Baoding, Hebei Province, 071003, China
| | - Zhuo Liu
- Hebei Key Laboratory of Low Carbon and High Efficiency Power Generation Technology, North China Electric Power University, Baoding, Hebei Province, 071003, China
| | - Xiang Wei
- Hebei Key Laboratory of Low Carbon and High Efficiency Power Generation Technology, North China Electric Power University, Baoding, Hebei Province, 071003, China
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