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Mbanga J, Abia ALK, Amoako DG, Essack SY. Longitudinal Surveillance of Antibiotic Resistance in Escherichia coli and Enterococcus spp. from a Wastewater Treatment Plant and Its Associated Waters in KwaZulu-Natal, South Africa. Microb Drug Resist 2021; 27:904-918. [PMID: 33512279 DOI: 10.1089/mdr.2020.0380] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
We assessed the prevalence, distribution, and antibiotic resistance patterns of Escherichia coli and Enterococcus spp. isolated from raw and treated wastewater of a major wastewater treatment plant (WWTP) in KwaZulu-Natal, South Africa and the receiving river water upstream and downstream from the WWTP discharge point. Escherichia coli and enterococci were isolated and counted using the Colilert®-18 Quanti-Tray® 2000 and Enterolert®-18 Quanti-Tray 2000 systems, respectively. A total of 580 quantitative PCR-confirmed E. coli and 579 enterococci were randomly chosen from positive samples and tested for in vitro antibiotic susceptibility using the disk diffusion assay against 20 and 16 antibiotics, respectively. The removal success of the bacterial species through the treatment procedure at the WWTP was expressed as log removal values (LRVs). Most E. coli were susceptible to meropenem (94.8%) and piperacillin-tazobactam (92.9%), with most Enterococcus susceptible to ampicillin (97.8%) and vancomycin (96.7%). In total, 376 (64.8%) E. coli and 468 (80.8%) Enterococcus isolates showed multidrug resistance (MDR). A total of 42.4% (246/580) E. coli and 65.1% (377/579) enterococci isolates had multiple antibiotic resistance indices >0.2. The LRV for E. coli ranged from 2.97 to 3.99, and for enterococci the range was observed from 1.83 to 3.98. A high proportion of MDR E. coli and enterococci were present at all sampled sites, indicating insufficient removal during wastewater treatment. There is a need to appraise the public health risks associated with bacterial contamination of environmental waters arising from such WWTPs to protect the health of users of the receiving water bodies.
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Affiliation(s)
- Joshua Mbanga
- Antimicrobial Research Unit, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
- Department of Applied Biology and Biochemistry, National University of Science and Technology, Bulawayo, Zimbabwe
| | - Akebe Luther King Abia
- Antimicrobial Research Unit, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Daniel Gyamfi Amoako
- Antimicrobial Research Unit, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Sabiha Y Essack
- Antimicrobial Research Unit, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
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Boonnorat J, Kanyatrakul A, Prakhongsak A, Ketbubpha K, Phattarapattamawong S, Treesubsuntorn C, Panichnumsin P. Biotoxicity of landfill leachate effluent treated by two-stage acclimatized sludge AS system and antioxidant enzyme activity in Cyprinus carpio. CHEMOSPHERE 2021; 263:128332. [PMID: 33297261 DOI: 10.1016/j.chemosphere.2020.128332] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 09/09/2020] [Accepted: 09/11/2020] [Indexed: 06/12/2023]
Abstract
This research comparatively investigates the biotoxicity of landfill leachate effluent from acclimatized and non-acclimatized sludge two-stage activated sludge (AS) systems. Both AS systems were operated with two leachate influent concentrations: moderate (condition 1) and elevated (condition 2). The biotoxicity of AS effluent of variable concentrations (10, 20, and 30% (v/v)) was assessed by the mortality rates of common carp (Cyprinus carpio) and glutathione-S-transferase (GST) enzyme activity. The treatment efficiency of the acclimatized sludge AS system for organic and inorganic compounds and nutrients (BOD, COD, TKN, NH4+, PO43-) were 75-96% under condition 1 and 79-93% under condition 2. The non-acclimatized sludge AS system achieved the treatment efficiency of 70-91% under condition 1 and 66-90% under condition 2. The acclimatized sludge AS system also achieved higher biodegradation of trace organic compounds, especially under condition 1. The effluent from acclimatized sludge AS system was less toxic to the common carp, as evidenced by lower mortality rates and higher GST activity. The findings revealed that the acclimatized sludge two-stage AS system could be deployed to effectively treat landfill leachate with moderate concentrations of compounds and trace organic contaminants. The acclimatized sludge AS is an efficient wastewater treatment solution for developing countries with limited technological and financial resources.
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Affiliation(s)
- Jarungwit Boonnorat
- Department of Environmental Engineering, Faculty of Engineering, Rajamangala University of Technology Thanyaburi (RMUTT), Klong 6, Pathum Thani, 12110, Thailand.
| | - Alongkorn Kanyatrakul
- Department of Environmental Engineering, Faculty of Engineering, Rajamangala University of Technology Thanyaburi (RMUTT), Klong 6, Pathum Thani, 12110, Thailand
| | - Apichai Prakhongsak
- Department of Environmental Engineering, Faculty of Engineering, Rajamangala University of Technology Thanyaburi (RMUTT), Klong 6, Pathum Thani, 12110, Thailand
| | - Kanjana Ketbubpha
- Department of Environmental Engineering, Faculty of Engineering, Rajamangala University of Technology Thanyaburi (RMUTT), Klong 6, Pathum Thani, 12110, Thailand
| | - Songkeart Phattarapattamawong
- Department of Environmental Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi (KMUTT), Thung Khru, Bangkok, 10140, Thailand
| | - Chairat Treesubsuntorn
- Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi (KMUTT), Bangkhuntien, Bangkok, 10150, Thailand
| | - Pornpan Panichnumsin
- Excellent Center of Waste Utilization and Management (EcoWaste), King Mongkut's University of Technology Thonburi (KMUTT), Bangkhuntien, Bangkok, 10150, Thailand; National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, 12120, Thailand
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Pei M, Zhang B, He Y, Su J, Gin K, Lev O, Shen G, Hu S. State of the art of tertiary treatment technologies for controlling antibiotic resistance in wastewater treatment plants. ENVIRONMENT INTERNATIONAL 2019; 131:105026. [PMID: 31351383 DOI: 10.1016/j.envint.2019.105026] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 07/15/2019] [Accepted: 07/15/2019] [Indexed: 05/27/2023]
Abstract
Antibiotic resistance genes (ARGs) have been considered as emerging contaminants of concern nowadays. There are no special technologies designed to directly remove ARGs in wastewater treatment plants (WWTPs). In order to reduce the risk of ARGs, it is vital to understand the efficiency of advanced treatment technologies in removing antibiotic resistance genes in WWTPs. This review highlights the application and efficiency of tertiary treatment technologies on the elimination of ARGs, s, based on an understanding of their occurrence and fate in WWTPs. These technologies include chemical-based processes such as chlorination, ozonation, ultraviolet, and advanced oxidation technology, as well as physical separation processes, biological processes such as constructed wetland and membrane bioreactor, and soil aquifer treatment. The merits, limitations and ameliorative measures of these processes are discussed, with the view to optimizing future treatment strategies and identifying new research directions.
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Affiliation(s)
- Mengke Pei
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Bo Zhang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Yiliang He
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jianqiang Su
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Road, Xiamen 361021, China
| | - Karina Gin
- Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576, Singapore
| | - Ovadia Lev
- The Casali Center and the Institute of Chemistry and The Harvey M. Krueger Family Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 91904, Israel
| | - Genxiang Shen
- Shanghai Academy of Environmental Sciences, Shanghai 200233, China
| | - Shuangqing Hu
- Shanghai Academy of Environmental Sciences, Shanghai 200233, China
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Boonnorat J, Kanyatrakul A, Prakhongsak A, Honda R, Panichnumsin P, Boonapatcharoen N. Effect of hydraulic retention time on micropollutant biodegradation in activated sludge system augmented with acclimatized sludge treating low-micropollutants wastewater. CHEMOSPHERE 2019; 230:606-615. [PMID: 31128507 DOI: 10.1016/j.chemosphere.2019.05.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 04/28/2019] [Accepted: 05/04/2019] [Indexed: 06/09/2023]
Abstract
This research investigates the effect of hydraulic retention time (HRT) on micropollutant biodegradation of two-stage activated sludge (AS) system augmented with acclimatized sludge treating low-micropollutants wastewater. The experimental wastewater was a mixture of landfill leachate and agriculture wastewater, and HRT was varied between 24, 18, and 12 h. The results showed that, under 24 h HRT, the micropollutant biodegradation efficiencies were 87-93% for bisphenol A (BPA), 2,6-di-tert-butyl-phenol (2,6-DTBP), di-butyl-phthalate (DBP), di-(ethylhexyl)-phthalate (DEHP); 75-81% for carbamazepine (CBZ), diclofenac (DCF); and 88% for N,N-diethylmeta-toluamide (DEET). The degradation efficiencies were similar under 18 h HRT: 87-93% for BPA, 2,6-DTBP, DBP, DEHP; 75-80% for CBZ, DCF; and 80% for DEET. However, the efficiencies substantially declined under 12 h HRT: 71-93%, 55-60%, and 50%, respectively. Importantly, the findings revealed that HRT plays a crucial part in micropollutant biodegradation of bioaugmented AS system. More specifically, too short an HRT (12 h) results in low micropollutant removal efficiency, and too long an HRT (24 h) contributes to low daily throughput and high treatment operation cost. As a result, moderate HRT (18 h) is operationally and economically optimal for bioaugmented AS system treating low-micropollutants wastewater.
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Affiliation(s)
- Jarungwit Boonnorat
- Division of Environmental Engineering, Faculty of Engineering, Rajamangala University of Technology Thanyaburi (RMUTT), Klong 6, Pathum Thani, 12110, Thailand.
| | - Alongkorn Kanyatrakul
- Division of Environmental Engineering, Faculty of Engineering, Rajamangala University of Technology Thanyaburi (RMUTT), Klong 6, Pathum Thani, 12110, Thailand
| | - Apichai Prakhongsak
- Division of Environmental Engineering, Faculty of Engineering, Rajamangala University of Technology Thanyaburi (RMUTT), Klong 6, Pathum Thani, 12110, Thailand
| | - Ryo Honda
- Faculty of Geosciences and Civil Engineering, Institute of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa, 920-1192, Japan
| | - Pornpan Panichnumsin
- Excellent Center of Waste Utilization and Management (ECoWaste), King Mongkut's University of Technology Thonburi (KMUTT), Bangkhuntien, Bangkok, 10150, Thailand; National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, 12120, Thailand
| | - Nimaradee Boonapatcharoen
- Excellent Center of Waste Utilization and Management (ECoWaste), King Mongkut's University of Technology Thonburi (KMUTT), Bangkhuntien, Bangkok, 10150, Thailand
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Ng C, Tan B, Jiang XT, Gu X, Chen H, Schmitz BW, Haller L, Charles FR, Zhang T, Gin K. Metagenomic and Resistome Analysis of a Full-Scale Municipal Wastewater Treatment Plant in Singapore Containing Membrane Bioreactors. Front Microbiol 2019; 10:172. [PMID: 30833934 PMCID: PMC6387931 DOI: 10.3389/fmicb.2019.00172] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 01/22/2019] [Indexed: 11/23/2022] Open
Abstract
Reclaimed water provides a water supply alternative to address problems of scarcity in urbanized cities with high living densities and limited natural water resources. In this study, wastewater metagenomes from 6 stages of a wastewater treatment plant (WWTP) integrating conventional and membrane bioreactor (MBR) treatment were evaluated for diversity of antibiotic resistance genes (ARGs) and bacteria, and relative abundance of class 1 integron integrases (intl1). ARGs confering resistance to 12 classes of antibiotics (ARG types) persisted through the treatment stages, which included genes that confer resistance to aminoglycoside [aadA, aph(6)-I, aph(3′)-I, aac(6′)-I, aac(6′)-II, ant(2″)-I], beta-lactams [class A, class C, class D beta-lactamases (blaOXA)], chloramphenicol (acetyltransferase, exporters, floR, cmIA), fosmidomycin (rosAB), macrolide-lincosamide-streptogramin (macAB, ereA, ermFB), multidrug resistance (subunits of transporters), polymyxin (arnA), quinolone (qnrS), rifamycin (arr), sulfonamide (sul1, sul2), and tetracycline (tetM, tetG, tetE, tet36, tet39, tetR, tet43, tetQ, tetX). Although the ARG subtypes in sludge and MBR effluents reduced in diversity relative to the influent, clinically relevant beta lactamases (i.e., blaKPC, blaOXA) were detected, casting light on other potential point sources of ARG dissemination within the wastewater treatment process. To gain a deeper insight into the types of bacteria that may survive the MBR removal process, genome bins were recovered from metagenomic data of MBR effluents. A total of 101 close to complete draft genomes were assembled and annotated to reveal a variety of bacteria bearing metal resistance genes and ARGs in the MBR effluent. Three bins in particular were affiliated to Mycobacterium smegmatis, Acinetobacter Iwoffii, and Flavobacterium psychrophila, and carried aquired ARGs aac(2′)-Ib, blaOXA−278, and tet36 respectively. In terms of indicator organisms, cumulative log removal values (LRV) of Escherichia coli, Enterococci, and P. aeruginosa from influent to conventional treated effluent was lower (0–2.4), compared to MBR effluent (5.3–7.4). We conclude that MBR is an effective treatment method for reducing fecal indicators and ARGs; however, incomplete removal of P. aeruginosa in MBR treated effluents (<8 MPN/100 mL) and the presence of ARGs and intl1 underscores the need to establish if further treatment should be applied prior to reuse.
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Affiliation(s)
- Charmaine Ng
- Department of Surgery, National University of Singapore, Singapore, Singapore
| | - Boonfei Tan
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Xiao-Tao Jiang
- Environmental Biotechnology Lab, Department of Civil and Environmental Engineering, The University of Hong Kong, Pokfulam, Hong Kong
| | - Xiaoqiong Gu
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore, Singapore
| | - Hongjie Chen
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore, Singapore
| | - Bradley William Schmitz
- JHU/Stantec Alliance, Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States
| | - Laurence Haller
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore, Singapore
| | - Francis Rathinam Charles
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore, Singapore
| | - Tong Zhang
- Environmental Biotechnology Lab, Department of Civil and Environmental Engineering, The University of Hong Kong, Pokfulam, Hong Kong
| | - Karina Gin
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore, Singapore.,NUS Environmental Research Institute, Singapore, Singapore
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6
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Ma J, Dai R, Chen M, Khan SJ, Wang Z. Applications of membrane bioreactors for water reclamation: Micropollutant removal, mechanisms and perspectives. BIORESOURCE TECHNOLOGY 2018; 269:532-543. [PMID: 30195697 DOI: 10.1016/j.biortech.2018.08.121] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 08/28/2018] [Accepted: 08/29/2018] [Indexed: 06/08/2023]
Abstract
Membrane bioreactors (MBRs) have attracted attention in water reclamation as a result of the recent technical advances and cost reduction in membranes. However, the increasing occurrence of micropollutants in wastewaters has posed new challenges. Therefore, we reviewed the current state of research to identify the outstanding needs in this field. In general, the fate of micropollutants in MBRs relates to sorption, biodegradation and membrane separation processes. Hydrophobic, nonionized micropollutants are favorable in sorption, and the biological degradation shows higher efficiency at relatively long SRTs (30-40 days) and HRTs (20-30 h), as a result of co-metabolism, metabolism and/or ion trapping. Although the membrane rejection rates for micropollutants are generally minor, final water quality can be improved via combination with other technologies. This review highlights the challenges and perspectives that should be addressed to facilitate the extended use of MBRs for the removal of micropollutants in water reclamation.
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Affiliation(s)
- Jinxing Ma
- State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Safety, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052, Australia
| | - Ruobin Dai
- State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Safety, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Mei Chen
- State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Safety, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Stuart J Khan
- UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052, Australia
| | - Zhiwei Wang
- State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Safety, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
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7
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Schoen ME, Jahne MA, Garland J. Human health impact of non-potable reuse of distributed wastewater and greywater treated by membrane bioreactors. MICROBIAL RISK ANALYSIS 2018; 9:72-81. [PMID: 35280215 PMCID: PMC8914979 DOI: 10.1016/j.mran.2018.01.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We assessed the annual probability of infection resulting from non-potable exposures to distributed greywater and domestic wastewater treated by an aerobic membrane bioreactor (MBR) followed by chlorination. A probabilistic quantitative microbial risk assessment was conducted for both residential and office buildings and a residential district using Norovirus, Rotavirus, Campylobacter jejuni, and Cryptosporidium spp. as reference pathogens. A Monte Carlo approach captured variation in pathogen concentration in the collected water and pathogen (or microbial surrogate) treatment performance, when available, for various source water and collection scale combinations. Uncertain inputs such as dose-response relationships and the volume ingested were treated deterministically and explored through sensitivity analysis. The predicted 95th percentile annual risks for non-potable indoor reuse of distributed greywater and domestic wastewater at district and building scales were less than the selected health benchmark of 10-4 infections per person per year (ppy) for all pathogens except Cryptosporidium spp., given the selected exposure (which included occasional, accidental ingestion), dose-response, and treatment performance assumptions. For Cryptosporidium spp., the 95th percentile annual risks for reuse of domestic wastewater (for all selected collection scenarios) and district-collected greywater were greater than the selected health benchmark when using the limited, available MBR treatment performance data; this finding is counterintuitive given the large size of Cryptosporidium spp. relative to the MBR pores. Therefore, additional data on MBR removal of protozoa is required to evaluate the proposed MBR treatment process for non-potable reuse. Although the predicted Norovirus annual risks were small across scenarios (less than 10-7 infections ppy), the risks for Norovirus remain uncertain, in part because the treatment performance is difficult to interpret given that the ratio of total to infectious viruses in the raw and treated effluents remains unknown. Overall, the differences in pathogen characterization between collection type (i.e., office vs. residential) and scale (i.e., district vs. building) drove the differences in predicted risk; and, the accidental ingestion event (although modeled as rare) determined the annual probability of infection. The predicted risks resulting from treatment malfunction scenarios indicated that online, real-time monitoring of both the MBR and disinfection processes remains important for non-potable reuse at distributed scales. The resulting predicted health risks provide insight on the suitability of MBR treatment for distributed, non-potable reuse at different collection scales and the potential to reduce health risks for non-potable reuse.
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Affiliation(s)
- Mary E. Schoen
- Soller Environmental, LLC, 3022 King St., Berkeley, CA 94703, USA
- Corresponding author. (M.E. Schoen)
| | - Michael A. Jahne
- U.S. Environmental Protection Agency, 26 W. Martin Luther King Drive, Cincinnati, OH 45268, USA
| | - Jay Garland
- U.S. Environmental Protection Agency, 26 W. Martin Luther King Drive, Cincinnati, OH 45268, USA
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Cheng H, Hong PY. Removal of Antibiotic-Resistant Bacteria and Antibiotic Resistance Genes Affected by Varying Degrees of Fouling on Anaerobic Microfiltration Membranes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:12200-12209. [PMID: 28957626 DOI: 10.1021/acs.est.7b03798] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
An anaerobic membrane bioreactor was retrofitted with polyvinylidene fluoride (PVDF) microfiltration membrane units, each of which was fouled to a different extent. The membranes with different degrees of fouling were evaluated for their efficiencies in removing three antibiotic-resistant bacteria (ARB), namely, blaNDM-1-positive Escherichia coli PI-7, blaCTX-M-15-positive Klebsiella pneumoniae L7, and blaOXA-48-positive E. coli UPEC-RIY-4, as well as their associated plasmid-borne antibiotic resistance genes (ARGs). The results showed that the log removal values (LRVs) of ARGs correlated positively with the extent of membrane fouling and ranged from 1.9 to 3.9. New membranes with a minimal foulant layer could remove more than 5 log units of ARB. However, as the membranes progressed to subcritical fouling, the LRVs of ARB decreased at increasing operating transmembrane pressures (TMPs). The LRV recovered back to 5 when the membrane was critically fouled, and the achieved LRV remained stable at different operating TMPs. Furthermore, characterization of the surface attributed the removal of both the ARB and ARGs to adsorption, which was facilitated by an increasing hydrophobicity and a decreasing surface ζ potential as the membranes fouled. Our results indicate that both the TMP and the foulant layer synergistically affected ARB removal, but the foulant layer was the main factor that contributed to ARG removal.
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Affiliation(s)
- Hong Cheng
- Division of Biological and Environmental Science & Engineering (BESE), Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology (KAUST) , Thuwal 23955, Saudi Arabia
| | - Pei-Ying Hong
- Division of Biological and Environmental Science & Engineering (BESE), Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology (KAUST) , Thuwal 23955, Saudi Arabia
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Abstract
Broad and increasing interest in sustainable wastewater treatment has led a paradigm shift towards more efficient means of treatment system operation. A key aspect of improving overall sustainability is the potential for direct wastewater effluent reuse. Anaerobic membrane bioreactors (AnMBRs) have been identified as an attractive option for producing high quality and nutrient-rich effluents during the treatment of municipal wastewaters. The introduction of direct effluent reuse does, however, raise several safety concerns related to its application. Among those concerns are the microbial threats associated with pathogenic bacteria as well as the emerging issues associated with antibiotic-resistant bacteria and the potential for proliferation of antibiotic resistance genes. Although there is substantial research evaluating these topics from the perspectives of anaerobic digestion and membrane bioreactors separately, little is known regarding how AnMBR systems can contribute to pathogen and antibiotic resistance removal and propagation in wastewater effluents. The aim of this review is to provide a current assessment of existing literature on anaerobic and membrane-based treatment systems as they relate to these microbial safety issues and utilize this assessment to identify areas of potential future research to evaluate the suitability of AnMBRs for direct effluent reuse.
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Wu B, Wang R, Fane AG. The roles of bacteriophages in membrane-based water and wastewater treatment processes: A review. WATER RESEARCH 2017; 110:120-132. [PMID: 27998784 DOI: 10.1016/j.watres.2016.12.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 11/20/2016] [Accepted: 12/04/2016] [Indexed: 05/04/2023]
Abstract
Membrane filtration processes have been widely applied in water and wastewater treatment for many decades. Concerns related to membrane treatment effectiveness, membrane lifespan, and membrane fouling control have been paid great attention. To achieve sustainable membrane operation with regards to low energy and maintenance cost, monitoring membrane performance and applying suitable membrane control strategies are required. As the most abundant species in water and wastewater, bacteriophages have shown great potential to be employed in membrane processes as (1) indicators to assess membrane performance considering their similar properties to human pathogenic waterborne viruses; (2) surrogate particles to monitor membrane integrity due to their nano-sized nature; and (3) biological agents to alleviate membrane fouling because of their antimicrobial properties. This study aims to provide a comprehensive review on the roles of bacteriophages in membrane-based water and wastewater treatment processes, with focuses on their uses for membrane performance examination, membrane integrity monitoring, and membrane biofouling control. The advantages, limitations, and influencing factors for bacteriophage-based applications are reported. Finally, the challenges and prospects of bacteriophage-based applications in membrane processes for water treatment are highlighted.
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Affiliation(s)
- Bing Wu
- Singapore Membrane Technology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One #06-08, 637141, Singapore.
| | - Rong Wang
- Singapore Membrane Technology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One #06-08, 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore.
| | - Anthony G Fane
- Singapore Membrane Technology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One #06-08, 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore
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11
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Harb M, Hong PY. Molecular-based detection of potentially pathogenic bacteria in membrane bioreactor (MBR) systems treating municipal wastewater: a case study. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:5370-5380. [PMID: 28013467 PMCID: PMC5352760 DOI: 10.1007/s11356-016-8211-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 12/05/2016] [Indexed: 05/23/2023]
Abstract
Although membrane bioreactor (MBR) systems provide better removal of pathogens compared to conventional activated sludge processes, they do not achieve total log removal. The present study examines two MBR systems treating municipal wastewater, one a full-scale MBR plant and the other a lab-scale anaerobic MBR. Both of these systems were operated using microfiltration (MF) polymeric membranes. High-throughput sequencing and digital PCR quantification were utilized to monitor the log removal values (LRVs) of associated pathogenic species and their abundance in the MBR effluents. Results showed that specific removal rates vary widely regardless of the system employed. Each of the two MBR effluents' microbial communities contained genera associated with opportunistic pathogens (e.g., Pseudomonas, Acinetobacter) with a wide range of log reduction values (< 2 to >5.5). Digital PCR further confirmed that these bacterial groups included pathogenic species, in several instances at LRVs different than those for their respective genera. These results were used to evaluate the potential risks associated both with the reuse of the MBR effluents for irrigation purposes and with land application of the activated sludge from the full-scale MBR system.
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Affiliation(s)
- Moustapha Harb
- Water Desalination and Reuse Center, Environmental Science and Engineering, King Abdullah University of Science and Technology (KAUST), 4700 King Abdullah Boulevard, Thuwal, 23955-6900, Saudi Arabia
| | - Pei-Ying Hong
- Water Desalination and Reuse Center, Environmental Science and Engineering, King Abdullah University of Science and Technology (KAUST), 4700 King Abdullah Boulevard, Thuwal, 23955-6900, Saudi Arabia.
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12
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Purnell S, Ebdon J, Buck A, Tupper M, Taylor H. Removal of phages and viral pathogens in a full-scale MBR: Implications for wastewater reuse and potable water. WATER RESEARCH 2016; 100:20-27. [PMID: 27176650 DOI: 10.1016/j.watres.2016.05.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 04/11/2016] [Accepted: 05/03/2016] [Indexed: 05/03/2023]
Abstract
The aim of this study was to demonstrate how seasonal variability in the removal efficacy of enteric viral pathogens from an MBR-based water recycling system might affect risks to human health if the treated product were to be used for the augmentation of potable water supplies. Samples were taken over a twelve month period (March 2014-February 2015), from nine locations throughout a water recycling plant situated in East London and tested for faecal indicator bacteria (thermotolerant coliforms, intestinal enterococci n = 108), phages (somatic coliphage, F-specific RNA phage and Bacteroides phage (GB-124) n = 108), pathogenic viruses (adenovirus, hepatitis A, norovirus GI/GII n = 48) and a range of physico-chemical parameters (suspended solids, DO, BOD, COD). Thermotolerant coliforms and intestinal enterococci were removed effectively by the water recycling plant throughout the study period. Significant mean log reductions of 3.9-5.6 were also observed for all three phage groups monitored. Concentrations of bacteria and phages did not vary significantly according to season (P < 0.05; Kruskal-Wallis), though recorded levels of norovirus (GI) were significantly higher during autumn/winter months (P = 0.027; Kruskal-Wallis). Log reduction values for norovirus and adenovirus following MBR treatment were 2.3 and 4.4, respectively. However, both adenovirus and norovirus were detected at low levels (2000 and 3240 gene copies/L, respectively) post chlorination in single samples. Whilst phage concentrations did correlate with viral pathogens, the results of this study suggest that phages may not be suitable surrogates, as viral pathogen concentrations varied to a greater degree seasonally than did the phage indicators and were detected on a number of occasions on which phages were not detected (false negative sample results).
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Affiliation(s)
- Sarah Purnell
- Environment and Public Health Research Group, Aquatic Research Centre, School of Environment and Technology, University of Brighton, Cockcroft Building, Lewes Road, Brighton, BN2 4GJ, United Kingdom.
| | - James Ebdon
- Environment and Public Health Research Group, Aquatic Research Centre, School of Environment and Technology, University of Brighton, Cockcroft Building, Lewes Road, Brighton, BN2 4GJ, United Kingdom
| | - Austen Buck
- Environment and Public Health Research Group, Aquatic Research Centre, School of Environment and Technology, University of Brighton, Cockcroft Building, Lewes Road, Brighton, BN2 4GJ, United Kingdom
| | - Martyn Tupper
- Thames Water Utilities Limited, Clearwater Court, Vastern Road, Reading, Berkshire RG1 8DB, United Kingdom
| | - Huw Taylor
- Environment and Public Health Research Group, Aquatic Research Centre, School of Environment and Technology, University of Brighton, Cockcroft Building, Lewes Road, Brighton, BN2 4GJ, United Kingdom
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13
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Mayer RE, Bofill-Mas S, Egle L, Reischer GH, Schade M, Fernandez-Cassi X, Fuchs W, Mach RL, Lindner G, Kirschner A, Gaisbauer M, Piringer H, Blaschke AP, Girones R, Zessner M, Sommer R, Farnleitner AH. Occurrence of human-associated Bacteroidetes genetic source tracking markers in raw and treated wastewater of municipal and domestic origin and comparison to standard and alternative indicators of faecal pollution. WATER RESEARCH 2016; 90:265-276. [PMID: 26745175 PMCID: PMC4884448 DOI: 10.1016/j.watres.2015.12.031] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 12/13/2015] [Accepted: 12/17/2015] [Indexed: 05/19/2023]
Abstract
This was a detailed investigation of the seasonal occurrence, dynamics, removal and resistance of human-associated genetic Bacteroidetes faecal markers (GeBaM) compared with ISO-based standard faecal indicator bacteria (SFIB), human-specific viral faecal markers and one human-associated Bacteroidetes phage in raw and treated wastewater of municipal and domestic origin. Characteristics of the selected activated sludge wastewater treatment plants (WWTPs) from Austria and Germany were studied in detail (WWTPs, n = 13, connected populations from 3 to 49000 individuals), supported by volume-proportional automated 24-h sampling and chemical water quality analysis. GeBaM were consistently detected in high concentrations in raw (median log10 8.6 marker equivalents (ME) 100 ml(-1)) and biologically treated wastewater samples (median log10 6.2-6.5 ME 100 ml(-1)), irrespective of plant size, type and time of the season (n = 53-65). GeBaM, Escherichia coli, and enterococci concentrations revealed the same range of statistical variability for raw (multiplicative standard deviations s* = 2.3-3.0) and treated wastewater (s* = 3.7-4.5), with increased variability after treatment. Clostridium perfringens spores revealed the lowest variability for raw wastewater (s* = 1.5). In raw wastewater correlations among microbiological parameters were only detectable between GeBaM, C. perfringens and JC polyomaviruses. Statistical associations amongst microbial parameters increased during wastewater treatment. Two plants with advanced treatment were also investigated, revealing a minimum log10 5.0 (10th percentile) reduction of GeBaM in the activated sludge membrane bioreactor, but no reduction of the genetic markers during UV irradiation (254 nm). This study highlights the potential of human-associated GeBaM to complement wastewater impact monitoring based on the determination of SFIB. In addition, human-specific JC polyomaviruses and adenoviruses seem to be a valuable support if highly specific markers are needed.
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Affiliation(s)
- R E Mayer
- Institute of Chemical Engineering, Research Division Biotechnology and Microbiology, Research Group Environmental Microbiology and Molecular Ecology, Vienna University of Technology, Gumpendorfer Straße 1a/166-5-2, A-1060, Vienna, Austria; InterUniversity Cooperation Centre for Water and Health, Austria
| | - S Bofill-Mas
- Laboratory of Virus Contaminants of Water and Food, Department of Microbiology, Faculty of Biology, University of Barcelona, Av. Diagonal 643, Barcelona, 08028, Spain
| | - L Egle
- Institute for Water Quality Resources and Waste Management, Vienna University of Technology, Karlsplatz 13/226, 1040, Vienna, Austria; Center of Water Resource Systems, Vienna University of Technology, Karlsplatz 13/222, 1040, Vienna, Austria
| | - G H Reischer
- Institute of Chemical Engineering, Research Division Biotechnology and Microbiology, Research Group Environmental Microbiology and Molecular Ecology, Vienna University of Technology, Gumpendorfer Straße 1a/166-5-2, A-1060, Vienna, Austria; InterUniversity Cooperation Centre for Water and Health, Austria
| | - M Schade
- Bavarian Environment Agency, Bürgermeister-Ulrich-Straße 160, 86179, Augsburg, Germany
| | - X Fernandez-Cassi
- Laboratory of Virus Contaminants of Water and Food, Department of Microbiology, Faculty of Biology, University of Barcelona, Av. Diagonal 643, Barcelona, 08028, Spain
| | - W Fuchs
- Department of Environmental Biotechnology at IFA, University of Natural Resources and Life Sciences, Gregor-Mendel-Straße 33, 1180, Vienna, Austria
| | - R L Mach
- Institute of Chemical Engineering, Research Division Biotechnology and Microbiology, Research Group Environmental Microbiology and Molecular Ecology, Vienna University of Technology, Gumpendorfer Straße 1a/166-5-2, A-1060, Vienna, Austria; InterUniversity Cooperation Centre for Water and Health, Austria
| | - G Lindner
- InterUniversity Cooperation Centre for Water and Health, Austria; Medical University Vienna, Institute for Hygiene and Applied Immunology, Water Hygiene, Kinderspitalgasse 15, A-1090, Vienna, Austria
| | - A Kirschner
- InterUniversity Cooperation Centre for Water and Health, Austria; Medical University Vienna, Institute for Hygiene and Applied Immunology, Water Hygiene, Kinderspitalgasse 15, A-1090, Vienna, Austria
| | - M Gaisbauer
- Schreiber-AWATEC Umwelttechnik GmbH, Bergmillergasse 3/1, 1140, Vienna, Austria
| | - H Piringer
- VRVis Research Center, Donau-City-Strasse 1, 1220, Vienna, Austria
| | - A P Blaschke
- InterUniversity Cooperation Centre for Water and Health, Austria; Center of Water Resource Systems, Vienna University of Technology, Karlsplatz 13/222, 1040, Vienna, Austria
| | - R Girones
- Laboratory of Virus Contaminants of Water and Food, Department of Microbiology, Faculty of Biology, University of Barcelona, Av. Diagonal 643, Barcelona, 08028, Spain
| | - M Zessner
- Institute for Water Quality Resources and Waste Management, Vienna University of Technology, Karlsplatz 13/226, 1040, Vienna, Austria; Center of Water Resource Systems, Vienna University of Technology, Karlsplatz 13/222, 1040, Vienna, Austria
| | - R Sommer
- InterUniversity Cooperation Centre for Water and Health, Austria; Medical University Vienna, Institute for Hygiene and Applied Immunology, Water Hygiene, Kinderspitalgasse 15, A-1090, Vienna, Austria.
| | - A H Farnleitner
- Institute of Chemical Engineering, Research Division Biotechnology and Microbiology, Research Group Environmental Microbiology and Molecular Ecology, Vienna University of Technology, Gumpendorfer Straße 1a/166-5-2, A-1060, Vienna, Austria; InterUniversity Cooperation Centre for Water and Health, Austria
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14
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Trinh T, Coleman HM, Stuetz RM, Drewes JE, Le-Clech P, Khan SJ. Hazardous events in membrane bioreactors – Part 2: Impacts on removal of trace organic chemical contaminants. J Memb Sci 2016. [DOI: 10.1016/j.memsci.2015.05.052] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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15
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Hazardous events in membrane bioreactors – Part 3: Impacts on microorganism log removal efficiencies. J Memb Sci 2016. [DOI: 10.1016/j.memsci.2015.10.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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16
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Trinh T, Branch A, Hambly AC, Carvajal G, Coleman HM, Stuetz RM, Drewes JE, Le-Clech P, Khan SJ. Hazardous events in membrane bioreactors – Part 1: Impacts on key operational and bulk water quality parameters. J Memb Sci 2016. [DOI: 10.1016/j.memsci.2015.03.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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17
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Yin Z, Tarabara VV, Xagoraraki I. Effect of pressure relaxation and membrane backwash on adenovirus removal in a membrane bioreactor. WATER RESEARCH 2016; 88:750-757. [PMID: 26595096 DOI: 10.1016/j.watres.2015.10.066] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 10/28/2015] [Accepted: 10/30/2015] [Indexed: 06/05/2023]
Abstract
Pressure relaxation and permeate backwash are two commonly used physical methods for membrane fouling mitigation in membrane bioreactor (MBR) systems. In order to assess the impact of these methods on virus removal by MBRs, experiments were conducted in a bench-scale submerged MBR treating synthetic wastewater. The membranes employed were hollow fibers with the nominal pore size of 0.45 μm. The experimental variables included durations of the filtration (tTMP>0), pressure relaxation (tTMP=0) and backwash (tTMP<0) steps. Both pressure relaxation and permeate backwash led to significant reductions in removal of human adenovirus (HAdV). For the same value of tTMP>0/tTMP=0, longer filtration/relaxation cycles (i.e. larger tTMP+tTMP=0) led to higher transmembrane pressure (TMP) but did not have a significant impact on HAdV removal. A shorter backwash (tTMP<0 = 10 min) at a higher flow rate (Q = 40 mL/min) resulted in more substantial decreases in TMP and HAdV removal than a longer backwash (tTMP<0 = 20 min) at a lower flow rate (Q = 20 mL/min) even though the backwash volume (QtTMP<0) was the same. HAdV removal returned to pre-cleaning levels within 16 h after backwash was applied. Moderate to strong correlations (R(2) = 0.63 to 0.94) were found between TMP and HAdV removal.
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Affiliation(s)
- Ziqiang Yin
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing, MI 48824, USA
| | - Volodymyr V Tarabara
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing, MI 48824, USA
| | - Irene Xagoraraki
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing, MI 48824, USA.
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18
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Chaudhry RM, Holloway RW, Cath TY, Nelson KL. Impact of virus surface characteristics on removal mechanisms within membrane bioreactors. WATER RESEARCH 2015; 84:144-52. [PMID: 26231580 DOI: 10.1016/j.watres.2015.07.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 07/06/2015] [Accepted: 07/13/2015] [Indexed: 05/06/2023]
Abstract
In this study we investigated the removal of viruses with similar size and shape but with different external surface capsid proteins by a bench-scale membrane bioreactor (MBR). The goal was to determine which virus removal mechanisms (retention by clean backwashed membrane, retention by cake layer, attachment to biomass, and inactivation) were most impacted by differences in the virus surface properties. Seven bench-scale MBR experiments were performed using mixed liquor wastewater sludge that was seeded with three lab-cultured bacteriophages with icosahedral capsids of ∼30 nm diameter (MS2, phiX174, and fr). The operating conditions were designed to simulate those at a reference, full-scale MBR facility. The virus removal mechanism most affected by virus type was attachment to biomass (removals of 0.2 log for MS2, 1.2 log for phiX174, and 3 log for fr). These differences in removal could not be explained by electrostatic interactions, as the three viruses had similar net negative charge when suspended in MBR permeate. Removals by the clean backwashed membrane (less than 1 log) and cake layer (∼0.6 log) were similar for the three viruses. A comparison between the clean membrane removals seen at the bench-scale using a virgin membrane (∼1 log), and the full-scale using 10-year old membranes (∼2-3 logs) suggests that irreversible fouling, accumulated on the membrane over years of operation that cannot be removed by cleaning, also contributes towards virus removal. This study enhances the current mechanistic understanding of virus removal in MBRs and will contribute to more reliable treatment for water reuse applications.
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Affiliation(s)
- Rabia M Chaudhry
- ReNUWIt (Reinventing the Nation's Urban Water Infrastructure), Engineering Research Center, University of California, Berkeley, CA 94720, USA; Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720, USA
| | - Ryan W Holloway
- ReNUWIt (Reinventing the Nation's Urban Water Infrastructure), Engineering Research Center, University of California, Berkeley, CA 94720, USA; Department of Civil & Environmental Engineering, Colorado School of Mines, Golden, CO 80401, USA
| | - Tzahi Y Cath
- ReNUWIt (Reinventing the Nation's Urban Water Infrastructure), Engineering Research Center, University of California, Berkeley, CA 94720, USA; Department of Civil & Environmental Engineering, Colorado School of Mines, Golden, CO 80401, USA
| | - Kara L Nelson
- ReNUWIt (Reinventing the Nation's Urban Water Infrastructure), Engineering Research Center, University of California, Berkeley, CA 94720, USA; Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720, USA.
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19
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Purnell S, Ebdon J, Buck A, Tupper M, Taylor H. Bacteriophage removal in a full-scale membrane bioreactor (MBR) - Implications for wastewater reuse. WATER RESEARCH 2015; 73:109-17. [PMID: 25655318 DOI: 10.1016/j.watres.2015.01.019] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 01/06/2015] [Accepted: 01/10/2015] [Indexed: 05/27/2023]
Abstract
The aim of this study was to assess the potential removal efficacy of viruses in a full-scale membrane bioreactor (MBR) wastewater reuse system, using a range of indigenous and 'spiked' bacteriophages (phages) of known size and morphology. Samples were taken each week for three months from nine locations at each treatment stage of the water recycling plant (WRP) and tested for a range of microbiological parameters (n = 135). Mean levels of faecal coliforms were reduced to 0.3 CFU/100 ml in the MBR product and were undetected in samples taken after the chlorination stage. A relatively large reduction (5.3 log) in somatic coliphages was also observed following MBR treatment. However, F-specific and human-specific (GB124) phages were less abundant at all stages, and demonstrated log reductions post-MBR of 3.5 and 3.8, respectively. In 'spiking' experiments, suspended 'spiked' phages (MS2 and B-14) displayed post-MBR log reductions of 2.25 and 2.30, respectively. The removal of these suspended phages, which are smaller than the membrane pore size (0.04 μm), also highlights the possible role of the membrane biofilm as an effective additional barrier to virus transmission. The findings from this study of a full-scale MBR system demonstrate that the enumeration of several phage groups may offer a practical and conservative way of assessing the ability of MBR to remove enteric viruses of human health significance. They also suggest that phage removal in MBR systems may be highly variable and may be closely related on the one hand to both the size and morphology of the viruses and, on the other, to whether or not they are attached to solids.
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Affiliation(s)
- Sarah Purnell
- Environment and Public Health Research Group, School of Environment and Technology, University of Brighton, Cockcroft Building, Lewes Road, Brighton, BN2 4GJ, United Kingdom.
| | - James Ebdon
- Environment and Public Health Research Group, School of Environment and Technology, University of Brighton, Cockcroft Building, Lewes Road, Brighton, BN2 4GJ, United Kingdom
| | - Austen Buck
- Environment and Public Health Research Group, School of Environment and Technology, University of Brighton, Cockcroft Building, Lewes Road, Brighton, BN2 4GJ, United Kingdom
| | - Martyn Tupper
- Thames Water Utilities Limited, Clearwater Court, Vastern Road, Reading, Berkshire RG1 8DB, United Kingdom
| | - Huw Taylor
- Environment and Public Health Research Group, School of Environment and Technology, University of Brighton, Cockcroft Building, Lewes Road, Brighton, BN2 4GJ, United Kingdom
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20
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Chaudhry RM, Nelson KL, Drewes JE. Mechanisms of pathogenic virus removal in a full-scale membrane bioreactor. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:2815-22. [PMID: 25642587 DOI: 10.1021/es505332n] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Four pathogenic virus removal mechanisms were investigated in a full-scale membrane bioreactor (MBR; nominal pore size 0.04 μm): (i) attachment of virus to mixed liquor solids; (ii) virus retention by a just backwashed membrane; (iii) virus retention by the membrane cake layer; and (iv) inactivation. We quantified adenovirus, norovirus genogroup II (GII), and F+ coliphage in the influent wastewater, the solid and liquid fractions of the mixed liquor, return flow, and permeate using quantitative PCR (adenovirus and norovirus GII) and infectivity assays (F+ coliphage). Permeate samples were collected 4-5 days, 1 day, 3 h, and immediately after chlorine enhanced backwashes. The MBR achieved high log removals for adenovirus (3.9 to 5.5), norovirus GII (4.6 to 5.7), and F+ coliphage (5.4 to 7.1). The greatest contribution to total removal was provided by the backwashed membrane, followed by inactivation, the cake layer, and attachment to solids. Increases in turbidity and particle counts after backwashes indicated potential breakthrough of particles, but virus removal following backwashes was still high. This study demonstrates the ability of the MBR process to provide over 4 logs of removal for adenovirus and norovirus GII, even after a partial loss of the cake layer, and provides evidence for assigning virus disinfection credit to similar MBRs used to reclaim wastewater for reuse.
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Affiliation(s)
- Rabia M Chaudhry
- ReNUWIt (Reinventing the Nation's Urban Water Infrastructure) Engineering Research Center, University of California, Berkeley, California, 94720, United States
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