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Song Z, Zhang L, Yang J, Ni SQ, Peng Y. Achieving high nitrogen and antibiotics removal efficiency by nZVI-C in partial nitritation/anammox system with a single-stage membrane-aerated biofilm reactor. JOURNAL OF HAZARDOUS MATERIALS 2024; 473:134626. [PMID: 38759403 DOI: 10.1016/j.jhazmat.2024.134626] [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: 04/26/2024] [Accepted: 05/13/2024] [Indexed: 05/19/2024]
Abstract
This study innovated constructed an activated carbon-loaded nano-zero-valent iron (nZVI-C) enhanced membrane aerated biofilm reactor (MABR) coupled partial nitritation/anammox (PN/A) system for optimizing nitrogen and antibiotics removal. Results showed that nitrogen and antibiotic removal efficiencies of 88.45 ± 0.14% and 89.90 ± 3.07% were obtained by nZVI-C, respectively. nZVI-C hastened Nitrosomonas enrichment (relative abundance raised from 2.85% to 12.28%) by increasing tryptophan content in EPS. Furthermore, nZVI-C proliferated amo gene by 3.92 times and directly generated electrons, stimulating Ammonia monooxygenase (AMO) co-metabolism activity. Concurrently, via antibiotic resistance genes (ARGs) horizontal transfer, Nitrosomonas synergized with Arenimonas and Comamonadaceae for efficient antibiotic removal. Moreover, nZVI-C mitigated antibiotics inhibition of electron transfer by proliferating genes for PN and anammox electron production (hao, hdh) and utilization (amo, hzs, nir). That facilitated electron transfer and synergistic substrate conversion between ammonia oxidizing bacteria (AOB) and anaerobic ammonia oxidizing bacteria (AnAOB). Finally, the high nitrogen removal efficiency of the MABR-PN/A system was achieved.
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Affiliation(s)
- Zixuan Song
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing 100124, China
| | - Li Zhang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing 100124, China.
| | - Jiachun Yang
- China Coal Technology & Engineering Group Co. Ltd., Tokyo 100-0011, Japan
| | - Shou-Qing Ni
- School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266237, China
| | - Yongzhen Peng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing 100124, China
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2
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Zheng P, Li W, Li Y, Cheng Y, Wang J, Mu Y, Shen J. Ammonia monooxygenase-mediated cometabolic biotransformation of volatile 4-chlorophenol in nitrifying counter-diffused biofilms: A combined molecular dynamics simulation, DFT calculation and experimental study. WATER RESEARCH 2024; 262:122090. [PMID: 39032340 DOI: 10.1016/j.watres.2024.122090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 07/01/2024] [Accepted: 07/12/2024] [Indexed: 07/23/2024]
Abstract
Ammonia monooxygenase (AMO)-mediated cometabolism of organic pollutants has been widely observed in biological nitrogen removal process. However, its molecular mechanism remains unclear, hindering its practical application. Furthermore, conventional nitrification systems encounter significant challenges such as air pollution and the loss of ammonia-oxidizing bacteria, when dealing with wastewater containing volatile organic pollutants. This study developed a nitrifying membrane-aerated biofilm reactor (MABR) to enhance the biodegradation of volatile 4-chlorophenol (4-CP). Results showed that 4-CP was primarily removed via Nitrosomonas nitrosa-mediated cometabolism in the presence of NH4+-N, supported by the increased nicotinamide adenine dinucleotide (NADH) and adenosine triphosphate (ATP) content, AMO activity and the related genes abundance. Hydroquinone, detected for the first time and produced via oxidative dechlorination, as well as 4-chlorocatechol was primary transformation products of 4-CP. Nitrosomonas nitrosa AMO structural model was constructed for the first time using homology modeling. Molecular dynamics simulation suggested that the ortho-carbon in the benzene ring of 4-CP was more prone to metabolismcompared to the ipso-carbon. Density functional theory calculation revealed that 4-CP was metabolized by AMO via H-abstraction-OH-rebound reaction, with a significantly higher rebound barrier at the ipso-carbon (16.37 kcal·mol-1) as compared to the ortho-carbon (6.7 kcal·mol-1). This study fills the knowledge gap on the molecular mechanism of AMO-mediated cometabolism of organic pollutants, providing practical and theoretical foundations for improving volatile organic pollutants removal through nitrifying MABR.
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Affiliation(s)
- Peng Zheng
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Wenqiang Li
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Yan Li
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
| | - Youpeng Cheng
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Jing Wang
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Yang Mu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Jinyou Shen
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
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Guo Y, Askari N, Smets I, Appels L. A review on co-metabolic degradation of organic micropollutants during anaerobic digestion: Linkages between functional groups and digestion stages. WATER RESEARCH 2024; 256:121598. [PMID: 38663209 DOI: 10.1016/j.watres.2024.121598] [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: 08/18/2023] [Revised: 03/13/2024] [Accepted: 04/09/2024] [Indexed: 05/12/2024]
Abstract
The emerging presence of organic micropollutants (OMPs) in water bodies produced by human activities is a source of growing concern due to their environmental and health issues. Biodegradation is a widely employed treatment method for OMPs in wastewater owing to its high efficiency and low operational cost. Compared to aerobic degradation, anaerobic degradation has numerous advantages, including energy efficiency and superior performance for certain recalcitrant compounds. Nonetheless, the low influent concentrations of OMPs in wastewater treatment plants (WWTPs) and their toxicity make it difficult to support the growth of microorganisms. Therefore, co-metabolism is a promising mechanism for OMP biodegradation in which co-substrates are added as carbon and energy sources and stimulate increased metabolic activity. Functional microorganisms and enzymes exhibit significant variations at each stage of anaerobic digestion affecting the environment for the degradation of OMPs with different structural properties, as these factors substantially influence OMPs' biodegradability and transformation pathways. However, there is a paucity of literature reviews that explicate the correlations between OMPs' chemical structure and specific metabolic conditions. This study provides a comprehensive review of the co-metabolic processes which are favored by each stage of anaerobic digestion and attempts to link various functional groups to their favorable degradation pathways. Furthermore, potential co-metabolic processes and strategies that can enhance co-digestion are also identified, providing directions for future research.
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Affiliation(s)
- Yutong Guo
- KU Leuven, Department of Chemical Engineering, Chemical and Biochemical Reactor Engineering and Safety (CREaS) Campus De Nayer, Jan Pieter De Nayerlaan 5, Sint-Katelijne-Waver 2860, Belgium
| | - Najmeh Askari
- KU Leuven, Department of Chemical Engineering, Chemical and Biochemical Reactor Engineering and Safety (CREaS) Campus De Nayer, Jan Pieter De Nayerlaan 5, Sint-Katelijne-Waver 2860, Belgium
| | - Ilse Smets
- KU Leuven, Department of Chemical Engineering, Chemical and Biochemical Reactor Engineering and Safety (CREaS), Celestijnenlaan 200F box 2424, Heverlee 3001, Belgium
| | - Lise Appels
- KU Leuven, Department of Chemical Engineering, Chemical and Biochemical Reactor Engineering and Safety (CREaS) Campus De Nayer, Jan Pieter De Nayerlaan 5, Sint-Katelijne-Waver 2860, Belgium.
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4
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Rui D, Liu K, Ma Y, Huang K, Chen M, Wu F, Zhang X, Ye L. Pilot-scale investigation of performance and microbial community in a novel system combining fixed and suspended activated sludge. ENVIRONMENTAL RESEARCH 2024; 246:118141. [PMID: 38191046 DOI: 10.1016/j.envres.2024.118141] [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: 10/19/2023] [Revised: 12/20/2023] [Accepted: 01/05/2024] [Indexed: 01/10/2024]
Abstract
The conventional activated sludge (CAS) process is a widely used method for wastewater treatment due to its effectiveness and affordability. However, it can be prone to sludge abnormalities such as sludge bulking/foaming and sludge loss, which can lead to a decrease in treatment efficiency. To address these issues, a novel bag-based fixed activated sludge (BBFAS) system utilizing mesh bags to contain the sludge was developed for low carbon/nitrogen ratio wastewater treatment. Pilot-scale experiments demonstrated that the BBFAS system could successfully avoid the sludge abnormalities. Moreover, it was not affected by mass transfer resistance and exhibited significantly higher nitrogen removal efficiency, surpassing that of the CAS system by up to 78%. Additionally, the BBFAS system demonstrated comparable organic matter removal efficiency to CAS system. 16S rRNA gene high-throughput sequencing revealed that the bacterial community structure within the BBFAS system was significantly different from that of the CAS system. The bacteria associated with ammonium removal were more abundant in the BBFAS system than in the CAS system. The abundance of Nitrospira in the BBFAS could reach up to 6% and significantly higher than that in the CAS system, and they were likely responsible for both ammonia-oxidizing and nitrite-oxidizing functions. Clear stratification of microbial communities was observed from the outer to inner layers of the bag components due to the gradients of dissolved oxygen and other substrates. Overall, this study presents a promising approach for avoiding activated sludge abnormalities while maintaining high pollutant removal performance.
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Affiliation(s)
- Dongni Rui
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China
| | - Kunlong Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China
| | - Yanyan Ma
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China
| | - Kailong Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China; Nanjing Jiangdao Institute of Environmental Research, Nanjing, 210019, China
| | - Mengxue Chen
- Nanjing Gaoke Environmental Technology Co., Ltd., Nanjing, 210038, China
| | - Fei Wu
- Nanjing Gaoke Environmental Technology Co., Ltd., Nanjing, 210038, China
| | - Xuxiang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China
| | - Lin Ye
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China.
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Zhang Y, Sang P, Wang K, Gao J, Liu Q, Wang J, Qian F, Shu Y, Hong P. Enhanced chromium and nitrogen removal by constructing a biofilm reaction system based on denitrifying bacteria preferential colonization theory. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 273:116156. [PMID: 38412631 DOI: 10.1016/j.ecoenv.2024.116156] [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: 01/04/2024] [Revised: 02/12/2024] [Accepted: 02/24/2024] [Indexed: 02/29/2024]
Abstract
Understanding the developmental characteristics of microbial communities in biofilms is crucial for designing targeted functional microbial enhancements for the remediation of complex contamination scenarios. The strong prioritization effect of microorganisms confers the ability to colonize strains that arrive first dominantly. In this study, the auto-aggregating denitrifying bacterial Pseudomonas stutzeri strain YC-34, which has both nitrogen and chromium removal characteristics, was used as a biological material to form a stable biofilm system based on the principle of dominant colonization and biofortification. The effect of the biofilm system on nitrogen and chromium removal was characterized by measuring the changes in the quality of influent and effluent water. The pattern of biofilm changes was analyzed by measuring biofilm content and thickness and characterizing extracellular polymer substances (EPS). Further analysis of the biofilm microbiota characteristics and potential functions revealed the mechanism of strain YC-34 biofortified biofilm. The results revealed that the biofilm system formed could achieve 90.56% nitrate-nitrogen removal with an average initial nitrate-nitrogen concentration of 51.9 mg/L and 40% chromium removal with an average initial hexavalent chromium Cr(VI) concentration of 7.12 mg/L. The biofilm properties of the system were comparatively analyzed during the biofilm formation period, the fluctuation period of Cr(VI)-stressed water quality, and the stabilization period of Cr(VI)-stressed water quality. The biofilm system may be able to increase the structure of hydrogen bonds, the type of protein secondary structure, and the abundance of amino acid-like components in the EPS, which may confer biofilm tolerance to Cr(VI) stress and allow the system to maintain a stable biofilm structure. Furthermore, microbial characterization indicated an increase in microbial diversity in the face of chromium stress, with an increase in the abundance of nitrogen removal-associated functional microbiota and an increasing trend in the abundance of nitrogen transfer pathways. These results demonstrate that the biofilm system is stable in nitrogen and chromium removal. This bioaugmentation method may provide a new way for the remediation of heavy metal-polluted water bodies and also provides theoretical and application parameters for the popularization and application of biofilm systems.
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Affiliation(s)
- Yancheng Zhang
- College of Life Sciences, School of Ecology and Environment, Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, Anhui Normal University, Wuhu 241002, China
| | - Pengcheng Sang
- College of Life Sciences, School of Ecology and Environment, Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, Anhui Normal University, Wuhu 241002, China
| | - Kuan Wang
- Wuhu Three Gorges Water Co., Ltd., Wuhu 241000, China
| | - Jingyi Gao
- College of Life Sciences, School of Ecology and Environment, Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, Anhui Normal University, Wuhu 241002, China
| | - Qiang Liu
- College of Life Sciences, School of Ecology and Environment, Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, Anhui Normal University, Wuhu 241002, China
| | - Jihong Wang
- Wuhu Three Gorges Water Co., Ltd., Wuhu 241000, China
| | - Fangping Qian
- China National Chemical Communication Construction Group Co., Ltd., Jinan 250102, China
| | - Yilin Shu
- College of Life Sciences, School of Ecology and Environment, Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, Anhui Normal University, Wuhu 241002, China
| | - Pei Hong
- College of Life Sciences, School of Ecology and Environment, Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, Anhui Normal University, Wuhu 241002, China.
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Tao H, Cao X, Song R, Zhou Z, Cheng F. Preparation of PDMS and PDMS-UiO-66 oxygen-rich membranes and modules for membrane-aerated biofilm reactors. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2024; 89:873-886. [PMID: 38423606 PMCID: wst_2024_043 DOI: 10.2166/wst.2024.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
A membrane-aerated biofilm reactor (MABR) combines membrane technology with biofilm processes and has unique advantages in the treatment of organic wastewater and volatile wastewater. The common membranes for MABR systems usually have relatively uneven pore structures and low bubble point pressure, resulting in unsatisfactory O2 utilization and wastewater treatment efficiency. In this work, polydimethylsiloxane (PDMS) and UiO-66 (a Zr-based metal organic framework) were coated on the surface of a commercial polypropylene (PP) hollow fiber membrane to prepare oxygen-rich MABR membranes and modules, which showed an attractive O2 utilization rate and wastewater treatment efficiency. The bubble points of the PDMS and PDMS-UiO-66 membranes were significantly higher than those of the PP membranes, and the PDMS-UiO-66 membranes had better oxygen enrichment capacity and biological affinity. The optimal PDMS-UiO-66 membrane modules had an O2 permeance of 31.65 GPU (1 GPU = 3.35 × 10-10 mol m-2 s-1 Pa-1), with O2/N2 selectivity of 2.21. The membrane hanging effect and processing capacity for domestic sewage were greatly improved. This study may provide insights and guidelines to fabricate porous mixed matrix membranes and modules in the industry for MABR. The developed products are expected to be applied in the actual separation process.
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Affiliation(s)
- Haiyan Tao
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China; Tianjin Key Laboratory of Aquatic Science and Technology, Tianjin Chengjian University, Tianjin 300384, China E-mail:
| | - Xiaochang Cao
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China; Tianjin Key Laboratory of Aquatic Science and Technology, Tianjin Chengjian University, Tianjin 300384, China
| | - Rujie Song
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China; Tianjin Key Laboratory of Aquatic Science and Technology, Tianjin Chengjian University, Tianjin 300384, China
| | - Zebin Zhou
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China; Tianjin Key Laboratory of Aquatic Science and Technology, Tianjin Chengjian University, Tianjin 300384, China
| | - Fang Cheng
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China; Tianjin Key Laboratory of Aquatic Science and Technology, Tianjin Chengjian University, Tianjin 300384, China
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Akkoyunlu B, Daly S, Cerrone F, Casey E. Investigating Mass Transfer and Reaction Engineering Characteristics in a Membrane Biofilm Using Cupriavidus necator H16. MEMBRANES 2023; 13:908. [PMID: 38132912 PMCID: PMC10744831 DOI: 10.3390/membranes13120908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 11/23/2023] [Accepted: 12/11/2023] [Indexed: 12/23/2023]
Abstract
Membrane biofilm reactors are a growing trend in wastewater treatment whereby gas-transfer membranes provide efficient bubbleless aeration. Recently, there has been a growing interest in using these bioreactors for industrial biotechnology using microorganisms that can metabolise gaseous substrates. Since gas fermentation is limited by the low solubilities of gaseous substrates in liquid media, it is critical to characterise mass transfer rates of gaseous substrates to enable the design of membrane biofilm reactors. The objective of this study is to measure and analyse mass transfer rates and reaction engineering characteristics for a single tube membrane biofilm reactor using Cupriavidus necator H16. At elevated Reynolds numbers, the dominant resistance for gas diffusion shifts from the liquid boundary layer to the membrane. The biofilm growth rate was observed to decrease after 260 μm at 96 h. After 144 h, some sloughing of the biofilm occurred. Oxygen uptake rate and substrate utilisation rate for the biofilm developed showed that the biofilm changes from a single-substrate limited regime to a dual-substrate-limited regime after 72 h which alters the localisation of the microbial activity within the biofilm. This study shows that this platform technology has potential applications for industrial biotechnology.
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Affiliation(s)
- Burcu Akkoyunlu
- School of Chemical and Bioprocess Engineering, University College Dublin, D04 V1W8 Dublin, Ireland; (B.A.); (S.D.)
- BiOrbic Bioeconomy SFI Research Centre, University College Dublin, D04 V1W8 Dublin, Ireland;
| | - Sorcha Daly
- School of Chemical and Bioprocess Engineering, University College Dublin, D04 V1W8 Dublin, Ireland; (B.A.); (S.D.)
- BiOrbic Bioeconomy SFI Research Centre, University College Dublin, D04 V1W8 Dublin, Ireland;
- School of Engineering, Faculty of Engineering and Science, University of Greenwich, Medway Campus, Chatham ME4 4AG, UK
| | - Federico Cerrone
- BiOrbic Bioeconomy SFI Research Centre, University College Dublin, D04 V1W8 Dublin, Ireland;
- UCD Earth Institute, School of Biomolecular and Biomedical Sciences, University College Dublin, D04 V1W8 Dublin, Ireland
- School of Biotechnology, Dublin City University, Glasnevin Campus, D09 N920 Dublin, Ireland
| | - Eoin Casey
- School of Chemical and Bioprocess Engineering, University College Dublin, D04 V1W8 Dublin, Ireland; (B.A.); (S.D.)
- BiOrbic Bioeconomy SFI Research Centre, University College Dublin, D04 V1W8 Dublin, Ireland;
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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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