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Zhang J, Xu Z, Chu W, Ma L, He H, Jin W, Fang C. Optimizing the placement of medical wastewater outlets in sewer systems to reduce chemical consumption at wastewater treatment plants. WATER RESEARCH 2024; 264:122205. [PMID: 39116612 DOI: 10.1016/j.watres.2024.122205] [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: 06/19/2024] [Revised: 07/30/2024] [Accepted: 08/01/2024] [Indexed: 08/10/2024]
Abstract
The severely low influent chemical oxygen demand (COD) concentration at wastewater treatment plants (WWTPs) has become a critical issue. A key factor is the excessive biodegradation of organic matter by microbial communities within sewer systems. Intense disinfection commonly adopted for medical wastewater leads to abundant residual chlorine entering sewers, likely causing significant changes in microbial communities and sewage quality in sewers, yet our understanding is limited. Through long-term sewer simulation batch tests, this study revealed the response mechanism of microbial communities to residual chlorine and its impact on organic matter concentration in sewage. Under residual chlorine stress, microbial community structure rapidly changed, and more complex microbial interactions were observed. Besides, pathways related to stress response such as two-component system were significantly enriched; pathways related to energy metabolism (such as carbon fixation in prokaryotes and citrate cycle) in microbial communities were inhibited, and carbon metabolism shifted from the Embden-Meyerhof pathway to the pentose phosphate pathway to enhance cellular reducing power, reduce oxidative stress, and consequently decrease organic matter degradation. Therefore, compared to sewers with normal disinfection, concentrations of COD and dissolved organic carbon in sewage under chlorine stress increased by 12.6 % and 7.4 %, respectively. Besides, the decay and transformation of residual chlorine in sewers were explored. These findings suggest a new approach to medical wastewater discharge management: placing the medical wastewater outlet at the upstream in sewer systems, which ensures that residual chlorine consumption reaches maximum during long-distance transportation, mitigating its harmful effects on WWTPs, and increases the influent organic matter concentration, thereby reducing the need for additional carbon sources.
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Affiliation(s)
- Jingyi Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Zuxin Xu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
| | - Wenhai Chu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
| | - Liping Ma
- School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Huan He
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Wei Jin
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Chao Fang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
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Liu Q, Chen J, Zhou Q, Hou Y, Li Z, Li W, Lv S, Ren N, Wang AJ, Huang C. Multi-omics analysis of nitrifying sludge under carbon disulfide stress: Nitrification performance and molecular mechanisms. WATER RESEARCH 2024; 258:121780. [PMID: 38761598 DOI: 10.1016/j.watres.2024.121780] [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: 03/11/2024] [Revised: 05/10/2024] [Accepted: 05/13/2024] [Indexed: 05/20/2024]
Abstract
Carbon disulfide (CS2) is a widely used enzyme inhibitor with cytotoxic properties, commonly employed in viscose fibers and cellophane production due to its non-polar characteristics. In industry, CS2 is often removed by aeration, however, residual CS2 may enter the wastewater treatment plants, impacting the performance of nitrifying sludge. Currently, there is a notable dearth of research on the response of nitrifying sludge to CS2-induced stress. This study delves into the alterations in the performance of nitrifying sludge under short-term and long-term CS2 stress, scrutinizes the toxic effects of CS2 on microbial cells, elucidates the succession of microbial community structure, and delineates changes in microbial metabolic products. The findings from short-term CS2 stress revealed that low concentrations of CS2 induced oxidative stress damage, which was subsequently repaired in cells. However, at concentrations of 100-200 mg/L, CS2 inhibited reactive oxygen species, superoxide dismutase, and catalase, which are associated with metabolic and antioxidant activities. The inhibition of nitrite oxidoreductase activity by high concentrations of CS2 was attributed to its impact on the enzyme's conformation. Prolonged CS2 stress resulted in an increase in the secretion of soluble extracellular polymeric substances in sludge, while CS2 was assimilated into sulfate. The analysis of sludge microbial community structure revealed a decline in the relative abundance of Rhodanobacter, which is associated with nitrification, and an increase in Sinomonas, involved in sulfur oxidation. Metabolite analysis results demonstrated that high concentrations of CS2 affect pantothenate and CoA biosynthesis, purine metabolism, and glutathione metabolism. This study elucidated the microbial response mechanism of nitrifying sludge under short-term and long-term CS2 stress. It also clarified the composition and function of microbial ecosystems, and identified key bacterial species and metabolites. It provides a basis for future research to reduce CS2 inhibition through approaches such as the addition of metal ions, the selection of efficient CS2-degrading strains, and the modification of strain metabolic pathways.
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Affiliation(s)
- Qian Liu
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, 523808, China
| | - Jie Chen
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, 523808, China
| | - Qi Zhou
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Yanan Hou
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin, 300384, China
| | - Zhiling Li
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Wei Li
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, 523808, China
| | - Sihao Lv
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, 523808, China
| | - Nanqi Ren
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China; School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China
| | - Ai-Jie Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China; School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China; Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China.
| | - Cong Huang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China.
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Xiong YT, Liao XW, Guo JS, Fang F, Chen YP, Yan P. Potential Role of the Anammoxosome in the Adaptation of Anammox Bacteria to Salinity Stress. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:6670-6681. [PMID: 38564406 DOI: 10.1021/acs.est.4c01417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
The underlying adaptative mechanisms of anammox bacteria to salt stress are still unclear. The potential role of the anammoxosome in modulating material and energy metabolism in response to salinity stress was investigated in this study. The results showed that anammox bacteria increased membrane fluidity and decreased mechanical properties by shortening the ladderane fatty acid chain length of anammoxosome in response to salinity shock, which led to the breakdown of the proton motive force driving ATP synthesis and retarded energy metabolism activity. Afterward, the fatty acid chain length and membrane properties were recovered to enhance the energy metabolic activity. The relative transmission electron microscopy (TEM) area proportion of anammoxosome decreased from 55.9 to 38.9% under salinity stress. The 3D imaging of the anammox bacteria based on Synchrotron soft X-ray tomography showed that the reduction in the relative volume proportion of the anammoxosome and the concave surfaces was induced by salinity stress, which led to the lower energy expenditure of the material transportation and provided more binding sites for enzymes. Therefore, anammox bacteria can modulate nitrogen and energy metabolism by changing the membrane properties and morphology of the anammoxosome in response to salinity stress. This study broadens the response mechanism of anammox bacteria to salinity stress.
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Affiliation(s)
- Yu-Tong Xiong
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Xi-Wen Liao
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Jin-Song Guo
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Fang Fang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - You-Peng Chen
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Peng Yan
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China
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Cheng M, Fu HM, Mao Z, Yan P, Weng X, Ma TF, Xu XW, Guo JS, Fang F, Chen YP. Motility behavior and physiological response mechanisms of aerobic denitrifier, Enterobacter cloacae strain HNR under high salt stress: Insights from individual cells to populations. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 914:170002. [PMID: 38220024 DOI: 10.1016/j.scitotenv.2024.170002] [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: 10/23/2023] [Revised: 12/20/2023] [Accepted: 01/06/2024] [Indexed: 01/16/2024]
Abstract
The motility behaviors at the individual-cell level and the collective physiological responsive behaviors of aerobic denitrifier, Enterobacter cloacae strain HNR under high salt stress were investigated. The results revealed that as salinity increased, electron transport activity and adenosine triphosphate content decreased from 15.75 μg O2/g/min and 593.51 mM/L to 3.27 μg O2/g/min and 5.34 mM/L, respectively, at 40 g/L, leading to a reduction in the rotation velocity and vibration amplitude of strain HNR. High salinity stress (40 g/L) down-regulated genes involved in ABC transporters (amino acids, sugars, metal ions, and inorganic ions) and activated the biofilm-related motility regulation mechanism in strain HNR, resulting in a further decrease in flagellar motility capacity and an increase in extracellular polymeric substances secretion (4.08 mg/g cell of PS and 40.03 mg/g cell of PN at 40 g/L). These responses facilitated biofilm formation and proved effective in countering elevated salt stress in strain HNR. Moreover, the genetic diversity associated with biofilm-related motility regulation in strain HNR enhanced the adaptability and stability of the strain HNR populations to salinity stress. This study enables a deeper understanding of the response mechanism of aerobic denitrifiers to high salt stress.
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Affiliation(s)
- Meng Cheng
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - Hui-Min Fu
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China; National Research Base of Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing 400067, China
| | - Zheng Mao
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China; Chongqing Institute of Geology and Mineral Resources, Chongqing 400042, China
| | - Peng Yan
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - Xun Weng
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - Teng-Fei Ma
- National Research Base of Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing 400067, China
| | - Xiao-Wei Xu
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - Jin-Song Guo
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - Fang Fang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - You-Peng Chen
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China.
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Li Z, Liu W, Rahaman MH, Chen Z, Yan J, Zhai J. Polystyrene microplastics accumulation in lab-scale vertical flow constructed wetlands: impacts and fate. JOURNAL OF HAZARDOUS MATERIALS 2024; 461:132576. [PMID: 37738848 DOI: 10.1016/j.jhazmat.2023.132576] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/29/2023] [Accepted: 09/16/2023] [Indexed: 09/24/2023]
Abstract
Microplastics (MPs) are ubiquitous pollutants that significantly threaten organisms and ecosystems. Constructed wetlands (CWs), a nature-based treatment technology, can effectively remove MPs from wastewater. However, the responses of CWs when exposed to MPs remain unclear. In this study, lab-scale vertical flow constructed wetlands (VFCWs) were installed for receiving polystyrene (PS) MPs at concentrations of 100 μg/L and 1000 μg/L. The results showed that exposure to PS-MPs has no effects on COD and TP removal in VFCWs, but TN removal decreased by 3.69-5.37 %. Further investigation revealed that PS-MPs significantly impacted microbial communities and metabolic functions. The abundances of predominant nitrifiers (Nitrospira and Nitrosomonas) and denitrifiers (Nakamurella, Bradyrhizobium, and Bacillus) in VFCWs were significantly reduced, aligning with the responses of key enzymes. The presence of PS-MPs also decreased nitrogen removal by plant uptake, leading to decreased plant biomass and chlorophyll by 39.32-48.75 % and 5.92-32.19 %, respectively. Notably, > 90 % removal rates were observed for PS-MPs within VFCWs. In addition to PS-MPs interception by VFCWs substrate, the increase of released benzenes indicated that the PS-MPs biodegradation occurred. Such insights are vital for developing sustainable solutions to mitigate MPs' adverse effects on ecosystems.
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Affiliation(s)
- Zhenchen Li
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Wenbo Liu
- Institute for Smart City of Chongqing University in Liyang, Chongqing University, Jiangsu 213300, China
| | - Md Hasibur Rahaman
- Institute for Smart City of Chongqing University in Liyang, Chongqing University, Jiangsu 213300, China
| | - Zhongbing Chen
- Department of Applied Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcka 129, Praha-Suchdol 16500, Czech Republic
| | - Jixia Yan
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Jun Zhai
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China; Institute for Smart City of Chongqing University in Liyang, Chongqing University, Jiangsu 213300, China.
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Liu M, Mahata C, Wang Z, Kumar S, Zheng Y. Comparative exploration of biological treatment of hydrothermal liquefaction wastewater from sewage sludge: Effects of culture, fermentation conditions, and ammonia stripping. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 349:119527. [PMID: 37951111 DOI: 10.1016/j.jenvman.2023.119527] [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: 08/15/2023] [Revised: 10/31/2023] [Accepted: 11/01/2023] [Indexed: 11/13/2023]
Abstract
Hydrothermal liquefaction wastewater from sewage sludge (sludge HTLWW) is an emerging waste stream that requires treatment before being discharged into the environment. Biological treatment of sludge HTLWW is an attractive option due to the low cost and operational flexibility. In this study, we investigated and compared the performance of three bacterial strains and four fungal strains for biodegradation of sludge HTLWW. Our screening experiments established pH and mineral supplementation (iron, magnesium, calcium, and phosphorus) conditions that greatly improved COD removal and chemical compound degradation by the microbes. An ammonia stripping pretreatment improved COD removal efficiency of Rhodococci jostii RHA1 by 44%. All tested bacterial strains can tolerate 10× dilution of HTLWW and remove 35-44% of COD in 2-15 days, while all tested fungal strains were able to tolerate 20× dilution and were better at degrading phenolic compounds than bacteria. HTLWW treatment with biomass pellets of fungus Aspergillus niger NRRL 2001 achieved the best COD removal efficiency of 47% in 12 days without the need of nutrient supplementation. Comparisons on chemical compound degradation by the tested microbes suggested that organic acids in HTLWW were highly degradable, followed by phenolic compounds. N-heterocyclic compounds were resistant to biodegradation and were removed by 38%. This study demonstrated pure culture biological treatment of sludge HTLWW with diverse types of microorganisms, which would guide the culture development and bioprocess parameter optimization for treating HTLWW of different compositions.
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Affiliation(s)
- Meicen Liu
- Department of Grain Science and Industry, Kansas State University, 1980 Kimball Avenue, Manhattan, KS, 66506, USA.
| | - Chandan Mahata
- Department of Biological Systems Engineering, Virginia Tech, 1230 Washington St. SW, Blacksburg, VA, 24061, USA
| | - Zhiwu Wang
- Department of Biological Systems Engineering, Virginia Tech, 1230 Washington St. SW, Blacksburg, VA, 24061, USA
| | - Sandeep Kumar
- Department of Civil and Environmental Engineering, Old Dominion University, Norfolk, VA, 23529, USA
| | - Yi Zheng
- Department of Grain Science and Industry, Kansas State University, 1980 Kimball Avenue, Manhattan, KS, 66506, USA.
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Wang L, Wang S, Chen C, Tang Y, Liu B. Multi-omics analysis to reveal key pathways involved in low C/N ratio stress response in Pseudomonas sp. LW60 with superior nitrogen removal efficiency. BIORESOURCE TECHNOLOGY 2023; 389:129812. [PMID: 37776911 DOI: 10.1016/j.biortech.2023.129812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 09/24/2023] [Accepted: 09/27/2023] [Indexed: 10/02/2023]
Abstract
In practical engineering, nitrogen removal at low temperatures or low C/N ratios is difficult. Although strains can remove nitrogen well at low temperatures, there is no research on the performance and deep mechanism of strains under low C/N ratio stress. In this study, Pseudomonas sp. LW60 with superior nitrogen removal efficiency under low C/N ratio stress was isolated at 4 °C. With a C/N ratio of 2-10, the NH4+-N removal efficiency was 40.02 %-100 % at 4 °C. Furthermore, the resistance mechanism of Pseudomonas sp. LW60 to low C/N ratio stress was deeply investigated by multi-omics. The results of transcriptome, proteome, and metabolome revealed that the resistance of strain LW60 to low C/N ratio stress was attributed to enhanced central carbon metabolism, amino acid metabolism, and ABC transporters, rather than nitrogen removal pathways. This study isolated a strain with low C/N ratio tolerance and deeply explored its tolerance mechanism by multi-omics.
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Affiliation(s)
- Li Wang
- College of Architecture and Environment, Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu, Sichuan 610207, China; Yibin Institute of Industrial Technology, Sichuan University Yibin Park, Section 2, Lingang Ave., Cuiping District, Yibin, Sichuan 644000, China
| | - Shipeng Wang
- College of Architecture and Environment, Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu, Sichuan 610207, China
| | - Chen Chen
- Litree Purifying Technology Co., Ltd, Haikou, Hainan 571126, China
| | - Yueqin Tang
- College of Architecture and Environment, Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu, Sichuan 610207, China
| | - Baicang Liu
- College of Architecture and Environment, Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu, Sichuan 610207, China; Yibin Institute of Industrial Technology, Sichuan University Yibin Park, Section 2, Lingang Ave., Cuiping District, Yibin, Sichuan 644000, China.
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Huang W, Li Y, Wang F, Feng L, Wang D, Ma Y, Wu Y, Luo J. Disinfectant sodium dichloroisocyanurate synergistically strengthened sludge acidogenic process and pathogens inactivation: Targeted upregulation of functional microorganisms and metabolic traits via self-adaptation. WATER RESEARCH 2023; 247:120787. [PMID: 37918196 DOI: 10.1016/j.watres.2023.120787] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 10/18/2023] [Accepted: 10/26/2023] [Indexed: 11/04/2023]
Abstract
Harmless and resourceful treatment of waste activated sludge (WAS) have been the crucial goal for building environmental-friendly and sustainable society, while the synergistic realization approach is currently limited. This work skillfully utilized the disinfectant sodium dichloroisocyanurate (NaDCC) to simultaneously achieve the pathogenic potential inactivation (decreased by 60.1 %) and efficient volatile fatty acids (VFAs) recovery (increased by 221.9 %) during WAS anaerobic fermentation in rather cost-effective way (Chemicals costs:0.4 USD/kg VFAs versus products benefits: 2.68 USD/kg chemical). Mechanistic analysis revealed that the C=O and NCl bonds in NaDCC could spontaneously absorb sludge (binding energy -4.9 kJ/mol), and then caused the sludge disintegration and organic substrates release for microbial utilization due to the oxidizability of NaDCC. The disruption of sludge structure along with the increase of bioavailable fermentation substrates contributed to the selectively regulation of microbial community via enriching VFAs-forming microorganisms (e.g., Pseudomonas and Streptomyces) and reducing VFAs-consuming microorganisms, especially aceticlastic methanogens (e.g., Methanothrix and Methanospirillum). Correspondingly, the metabolic functions of membrane transport, substrate metabolism, pyruvate metabolism, and fatty acid biosynthesis locating in the central pathway of VFAs production were all upregulated while the methanogenic step was inhibited (especially acetate-type methanogenic pathway). Further exploration unveiled that for those enriched functional anaerobes were capable to activate the self-adaptive systems of DNA replication, SOS response, oxidative stress defense, efflux pump, and energy metabolism to counteract the unfavorable NaDCC stress and maintain high microbial activities for efficient VFAs yields. This study would provide a novel strategy for synergistic realization of harmless and resourceful treatment of WAS, and identify the interrelations between microbial metabolic regulations and adaptive responses.
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Affiliation(s)
- Wenxuan Huang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Yi Li
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Feng Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Leiyu Feng
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Dongbo Wang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China
| | - Yingqun Ma
- Shaanxi Key Laboratory of Energy Chemical Process Intensification, School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Yang Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
| | - Jingyang Luo
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China.
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Mishra S, Cheng L, Lian Y. Response of biofilm-based systems for antibiotics removal from wastewater: Resource efficiency and process resiliency. CHEMOSPHERE 2023; 340:139878. [PMID: 37604340 DOI: 10.1016/j.chemosphere.2023.139878] [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: 05/28/2023] [Revised: 07/23/2023] [Accepted: 08/17/2023] [Indexed: 08/23/2023]
Abstract
Biofilm-based systems have efficient stability to cope-up influent shock loading with protective and abundant microbial assemblage, which are extensively exploited for biodegradation of recalcitrant antibiotics from wastewater. The system performance is subject to biofilm types, chemical composition, growth and thickness maintenance. The present study elaborates discussion on different type of biofilms and their formation mechanism involving extracellular polymeric substances secreted by microbes when exposed to antibiotics-laden wastewater. The biofilm models applied for estimation/prediction of biofilm-based systems performance are explored to classify the application feasibility. Further, the critical review of antibiotics removal efficiency, design and operation of different biofilm-based systems (e.g. rotating biological contactor, membrane biofilm bioreactor etc.) is performed. Extending the information on effect of various process parameters (e.g. hydraulic retention time, pH, biocarrier filling ratio etc.), the microbial community dynamics responsible of antibiotics biodegradation in biofilms, the technological problems, related prospective and key future research directions are demonstrated. The biofilm-based system with biocarriers filling ratio of ∼50-70% and predominantly enriched with bacterial species of phylum Proteobacteria protected under biofilm thickness of ∼1600 μm is effectively utilized for antibiotic biodegradation (>90%) when operated at DO concentration ≥3 mg/L. The C/N ratio ≥1 is best suitable condition to eliminate antibiotic pollution from biofilm-based systems. Considering the significance of biofilm-based systems, this review study could be beneficial for the researchers targeting to develop sustainable biofilm-based technologies with feasible regulatory strategies for treatment of mixed antibiotics-laden real wastewater.
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Affiliation(s)
- Saurabh Mishra
- Yangtze Institute for Conservation and Development, Hohai University, Nanjing, 210098, Jiangsu, China; Institute of Water Science and Technology, Hohai University, Nanjing, Jiangsu, 210098, China; State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, 210098, Jiangsu, China.
| | - Liu Cheng
- College of Environment, Hohai University, Nanjing, Jiangsu Province, 210098, China
| | - Yanqing Lian
- Yangtze Institute for Conservation and Development, Hohai University, Nanjing, 210098, Jiangsu, China; State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, 210098, Jiangsu, China.
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