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Lau SS, Bokenkamp K, Tecza A, Wagner ED, Plewa MJ, Mitch WA. Mammalian Cell Genotoxicity of Potable Reuse and Conventional Drinking Waters. Environ Sci Technol 2024. [PMID: 38709862 DOI: 10.1021/acs.est.4c01596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Potable reuse water is increasingly part of the water supply portfolio for municipalities facing water shortages, and toxicity assays can be useful for evaluating potable reuse water quality. We examined the Chinese hamster ovary cell acute direct genotoxicity of potable reuse waters contributed by disinfection byproducts (DBPs) and anthropogenic contaminants and used the local conventional drinking waters as benchmarks for evaluating potable reuse water quality. Our results showed that treatment trains based on reverse osmosis (RO) were more effective than RO-free treatment trains for reducing the genotoxicity of influent wastewaters. RO-treated reuse waters were less genotoxic than the local tap water derived from surface water, whereas reuse waters not treated by RO were similarly genotoxic as the local drinking waters when frequent replacement of granular activated carbon limited contaminant breakthrough. The genotoxicity contributed by nonvolatile, uncharacterized DBPs and anthropogenic contaminants accounted for ≥73% of the total genotoxicity. The (semi)volatile DBPs of current research interest contributed 2-27% toward the total genotoxicity, with unregulated DBPs being more important genotoxicity drivers than regulated DBPs. Our results underscore the need to look beyond known, (semi)volatile DBPs and the importance of determining whole water toxicity when assessing the quality of disinfected waters.
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Affiliation(s)
- Stephanie S Lau
- Department of Civil and Environmental Engineering, Stanford University, 473 Via Ortega, Stanford, California 94305, United States
| | - Katherine Bokenkamp
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, 1101 West Peabody Dr., Urbana, Illinois 61801, United States
- Safe Global Water Institute, University of Illinois at Urbana-Champaign, 205 North Mathews Ave., Urbana, Illinois 61801, United States
| | - Aleksander Tecza
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, 1101 West Peabody Dr., Urbana, Illinois 61801, United States
- Safe Global Water Institute, University of Illinois at Urbana-Champaign, 205 North Mathews Ave., Urbana, Illinois 61801, United States
| | - Elizabeth D Wagner
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, 1101 West Peabody Dr., Urbana, Illinois 61801, United States
- Safe Global Water Institute, University of Illinois at Urbana-Champaign, 205 North Mathews Ave., Urbana, Illinois 61801, United States
| | - Michael J Plewa
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, 1101 West Peabody Dr., Urbana, Illinois 61801, United States
- Safe Global Water Institute, University of Illinois at Urbana-Champaign, 205 North Mathews Ave., Urbana, Illinois 61801, United States
| | - William A Mitch
- Department of Civil and Environmental Engineering, Stanford University, 473 Via Ortega, Stanford, California 94305, United States
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2
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Plata S, Childress AE, McCurry DL. Minimizing N-Nitrosodimethylamine Formation During Disinfection of Blended Seawater and Wastewater Effluent. ACS ES T Water 2024; 4:1498-1507. [PMID: 38633366 PMCID: PMC11019544 DOI: 10.1021/acsestwater.3c00617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 01/12/2024] [Accepted: 01/16/2024] [Indexed: 04/19/2024]
Abstract
Augmenting seawater with wastewater has the potential to reduce the energy demand and environmental impacts associated with seawater desalination. Alternatively, as wastewater reuse becomes more widespread, augmenting wastewater with seawater can increase the available water supply. However, the chemistry of disinfecting a blended stream has not been explored. Toxic byproducts, including N-nitrosodimethylamine (NDMA), are expected to form during disinfection, and the extent of formation will likely be a function of which stream is chlorinated and whether disinfection happens before or after blending. In this work, three blending-disinfection scenarios were modeled and experimentally evaluated in bench-scale systems treating synthetic and authentic waters. Modeling results suggested that chlorinating preblended wastewater and seawater would produce the most NDMA because it yielded the highest concentrations of bromochloramine, which was previously found to promote NDMA formation. However, chlorinating wastewater prior to blending with seawater, which modeling indicated would form the most dichloramine, produced the most NDMA in experiments. When seawater was disinfected prior to blending with wastewater, bromide likely converted most chlorine to free bromine. Bromamines formed after blending, however, did not lead to an elevated level of NDMA formation. Therefore, to minimize NDMA formation when disinfecting blended wastewater-seawater, seawater should be disinfected prior to introducing wastewater.
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Affiliation(s)
| | - Amy E. Childress
- Astani Department of Civil
and Environmental Engineering, University
of Southern California, Los Angeles, California 90089, United States
| | - Daniel L. McCurry
- Astani Department of Civil
and Environmental Engineering, University
of Southern California, Los Angeles, California 90089, United States
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3
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Li L, Haak L, Guarin TC, Teel L, Sundaram V, Pagilla KR. Per- and poly-fluoroalkyl substances removal in multi-barrier advanced water purification system for indirect potable reuse. Water Environ Res 2024; 96:e10990. [PMID: 38291828 DOI: 10.1002/wer.10990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/27/2023] [Accepted: 01/02/2024] [Indexed: 02/01/2024]
Abstract
The study evaluated the removal efficacy of per- and poly-fluoroalkyl substances (PFAS) across various advanced water treatment (AWT) processes in a field-scale AWT train using secondary effluent samples from a full-scale water reclamation facility (WRF). Samples collected from April to October 2020 revealed PFCAs as the dominant PFAS compounds in the WRF secondary effluent, with PFPeA having the highest average concentration and PFSAs in notably lower amounts. Temporal fluctuations in total PFAS concentrations peaked in September 2020, which may reflect the seasonality in PFAS discharges related to applications like AFFFs and pesticides. In assessing AWT processes, coagulation-flocculation-clarification-filtration system showed no notable PFAS reduction, while ozonation resulted in elevated PFBS and PFBA concentrations. Biological activated carbon (BAC) filtration effectively removed long-chain PFAS like PFOS and PFHxS but saw increased concentrations of short-chain PFAS post-treatment. Granular activated carbon (GAC) filtration was the most effective treatment, reducing all PFSAs below the detection limits and significantly decreasing most PFCAs, though short-chain PFCAs persisted. UV treatment did not remove short-chain PFCAs such as PFBA, PFPeA, and PFHxA. The findings highlight the efficacy of AWT processes like GAC in PFAS reduction for potable reuse, but also underscore the challenge presented by short-chain PFAS, emphasizing the need for tailored treatment strategies. PRACTITIONER POINTS: Secondary effluents showed higher concentrations of PFCAs compared to PFSAs. Advanced water treatment effectively removes long-chain PFAS but not short-chain. Ozonation may contribute to formation of short-chain PFAS. BAC is less effective on short-chain PFAS, requiring further GAC treatment.
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Affiliation(s)
- Lin Li
- Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada, USA
| | - Laura Haak
- Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada, USA
| | - Tatiana C Guarin
- Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada, USA
- UNAB's Circular Bioeconomy Research Center, Autonomous University of Bucaramanga, Bucaramanga, Colombia
| | - Lydia Teel
- Truckee Meadows Water Authority, Reno, Nevada, USA
| | | | - Krishna R Pagilla
- Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada, USA
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4
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Wang K, Shang C, Yin R, Xiang Y. Generation of Reactive Nitrogen Species in UV Photolysis of Dichloramine and Their Incorporation into Nitrogenous Byproducts. Environ Sci Technol 2023; 57:18735-18743. [PMID: 37126657 DOI: 10.1021/acs.est.2c08810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Dichloramine (NHCl2) often coexists with monochloramine (NH2Cl) in reverse osmosis (RO) permeate in potable reuse scenarios when NH2Cl is added upstream of RO for membrane fouling control such that UV photolysis of NHCl2 occurs during the downstream UV/chloramine process. However, the formation of reactive nitrogen species (RNS) and their incorporation into byproducts during the UV/NHCl2 process are largely unknown. This study quantitatively evaluated the generation of RNS in the UV/NHCl2 process and investigated the role of RNS in micropollutant transformation. UV photolysis of NHCl2 produced comparable RNS concentration to that of NH2Cl at the same oxidant dosage (100 μM) at pH 5.5. Under the experimental conditions, the RNS contributed greatly (40.6%) to N,N-diethyl-3-methylbenzamide (DEET) degradation. By using 15N-labeling and mass spectrometry methods, seven nitrogenous byproducts of DEET degradation with the incorporation of nitrogen originating from the RNS were detected. Among these seven byproducts, six were identified to contain a nitro group (-NO2). While the UV/NHCl2 process formed comparable intensities of -NO-containing products to those in the UV/NH2Cl process, the later process formed 3-91% higher intensities of -NO2-containing products. These findings are essential in furthering our understanding of the contribution of the UV/NHCl2 process in potable reuse scenarios.
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Affiliation(s)
- Kun Wang
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon 000, Hong Kong, SAR, China
| | - Chii Shang
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon 000, Hong Kong, SAR, China
- Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon 000, Hong Kong, SAR, China
| | - Ran Yin
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon 000, Hong Kong, SAR, China
| | - Yingying Xiang
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon 000, Hong Kong, SAR, China
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5
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Jones CH, Wylie V, Ford H, Fawell J, Holmer M, Bell K. A robust scenario analysis approach to water recycling quantitative microbial risk assessment. J Appl Microbiol 2023; 134:7043458. [PMID: 36796790 DOI: 10.1093/jambio/lxad029] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 01/18/2023] [Accepted: 02/15/2023] [Indexed: 02/18/2023]
Abstract
AIMS The growing need to access recycled water as a source for drinking water supply necessitates management of perceived risks. This study aimed to use quantitative microbial risk analysis (QMRA) to evaluate microbiological risks of indirect water recycling. METHODS AND RESULTS Scenario analyses of risk probabilities of pathogen infection were conducted to investigate four key quantitative microbial risk assessment model assumptions: treatment process failure, drinking water consumption events per day, inclusion or exclusion of an engineered storage buffer, and treatment process redundancy. Results demonstrated that the proposed water recycling scheme could meet WHO pathogen risk guidelines of ∼10-3 annual risk of infection under 18 simulated scenarios.
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Affiliation(s)
| | - Varsha Wylie
- Southern Water Services Limited, Lewes Road, Falmer, Brighton BN1 9PY, United Kingdom
| | - Hannah Ford
- El Toro Water District, 24251 Los Alisos Blvd, Lake Forest, CA 92630, United States
| | - John Fawell
- Independent Consultant, Bourne End SL8 5UW, United Kingdom
| | - Melanie Holmer
- Brown and Caldwell, 202 Cousteau Place, Suite 175, Davis, CA 95618, United States
| | - Katherine Bell
- Brown and Caldwell, 220 Athens Way, Suite 500, Nashville, TN 37228, United States
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6
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Peterson ES, Summers RS, Cook SM. Control of Pre-formed Halogenated Disinfection Byproducts with Reuse Biofiltration. Environ Sci Technol 2023; 57:2516-2526. [PMID: 36724198 DOI: 10.1021/acs.est.2c05504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Disinfection byproduct (DBP) pre-formation is a major issue when prechlorination is used before or during advanced treatment of impacted drinking water sources. Control strategies for pre-formed DBPs before final disinfection, especially for currently nonregulated although highly toxic DBP species, are not yet established. This study evaluated the biodegradation potential of pre-formed DBPs, including haloacetonitriles (HANs), haloacetamides (HAMs), and haloacetaldehydes (HALs), during biofiltration with sand, anthracite, and biological activated carbon of three wastewater effluents under potable reuse conditions. Up to 90%+ removal of di- and trihalogenated HANs, HAMs, and HALs was observed, and removal was associated with active heterotrophic biomass and removal of biodegradable organic carbon. Unlike the microbial dehalogenation pathway of haloacetic acids (HAAs), removal of HANs and HAMs appeared to result from a biologically mediated hydrolysis pathway (i.e., HANs to HAMs and HAAs) that may be prone to inhibition. After prechlorination, biofiltration effectively controlled pre-formed DBP concentrations (e.g., from 271 μg/L to as low as 22 μg/L in total) and DBP-associated calculated toxicity (e.g., 96%+ reduction). Abiotic residual adsorption capacity in biological activated carbon media was important for controlling trihalomethanes. Overall, the toxicity-driving DBP species exhibited high biodegradation potential and biofiltration showed significant promise as a pre-formed DBP control technology.
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Affiliation(s)
- Eric S Peterson
- Environmental Engineering Program, University of Colorado Boulder, 428 UCB, Boulder, Colorado 80309, United States
| | - R Scott Summers
- Environmental Engineering Program, University of Colorado Boulder, 428 UCB, Boulder, Colorado 80309, United States
| | - Sherri M Cook
- Environmental Engineering Program, University of Colorado Boulder, 428 UCB, Boulder, Colorado 80309, United States
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7
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Miller S, Greenwald H, Kennedy LC, Kantor RS, Jiang R, Pisarenko A, Chen E, Nelson KL. Microbial Water Quality through a Full-Scale Advanced Wastewater Treatment Demonstration Facility. ACS ES T Eng 2022; 2:2206-2219. [PMID: 36530600 PMCID: PMC9745798 DOI: 10.1021/acsestengg.2c00198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 09/14/2022] [Accepted: 09/15/2022] [Indexed: 06/17/2023]
Abstract
The fates of viruses, bacteria, and antibiotic resistance genes during advanced wastewater treatment are important to assess for implementation of potable reuse systems. Here, a full-scale advanced wastewater treatment demonstration facility (ozone, biological activated carbon filtration, micro/ultrafiltration, reverse osmosis, and advanced oxidation) was sampled over three months. Atypically, no disinfectant residual was applied before the microfiltration step. Microbial cell concentrations and viability were assessed via flow cytometry and adenosine triphosphate (ATP). Concentrations of bacteria (16S rRNA gene), viruses (human adenovirus and JC polyomavirus), and antibiotic resistance genes (sul1 and bla TEM ) were assessed via quantitative PCR following the concentration of large sample volumes by dead-end ultrafiltration. In all membrane filtration permeates, microbial concentrations were higher than previously reported for chloraminated membranes, and log10 reduction values were lower than expected. Concentrations of 16S rRNA and sul1 genes were reduced by treatment but remained quantifiable in reverse osmosis permeate. It is unclear whether sul1 in the RO permeate was from the passage of resistance genes or new growth of microorganisms, but the concentrations were on the low end of those reported for conventional drinking water distribution systems. Adenovirus, JC polyomavirus, and bla TEM genes were reduced below the limit of detection (∼10-2 gene copies per mL) by microfiltration. The results provide insights into how treatment train design and operation choices affect microbial water quality as well as the use of flow cytometry and ATP for online monitoring and process control.
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Affiliation(s)
- Scott Miller
- Department
of Civil and Environmental Engineering, College of Engineering, University of California, Berkeley, Berkeley, California 94720, United States
- National
Science Foundation Engineering Research Center for Re-inventing the
Nation’s Urban Water Infrastructure (ReNUWIt), Berkeley, California 94720, United States
| | - Hannah Greenwald
- Department
of Civil and Environmental Engineering, College of Engineering, University of California, Berkeley, Berkeley, California 94720, United States
- National
Science Foundation Engineering Research Center for Re-inventing the
Nation’s Urban Water Infrastructure (ReNUWIt), Berkeley, California 94720, United States
| | - Lauren C. Kennedy
- Department
of Civil and Environmental Engineering, College of Engineering, University of California, Berkeley, Berkeley, California 94720, United States
- National
Science Foundation Engineering Research Center for Re-inventing the
Nation’s Urban Water Infrastructure (ReNUWIt), Berkeley, California 94720, United States
- Department
of Civil and Environmental Engineering, College of Engineering, Stanford University, Stanford, California 94305, United States
| | - Rose S. Kantor
- Department
of Civil and Environmental Engineering, College of Engineering, University of California, Berkeley, Berkeley, California 94720, United States
- National
Science Foundation Engineering Research Center for Re-inventing the
Nation’s Urban Water Infrastructure (ReNUWIt), Berkeley, California 94720, United States
| | - Renjing Jiang
- Department
of Civil and Environmental Engineering, College of Engineering, University of California, Berkeley, Berkeley, California 94720, United States
- National
Science Foundation Engineering Research Center for Re-inventing the
Nation’s Urban Water Infrastructure (ReNUWIt), Berkeley, California 94720, United States
| | - Aleksey Pisarenko
- Trussell
Technologies, Inc., Solana
Beach, California 92075, United States
| | - Elise Chen
- Trussell
Technologies, Inc., Solana
Beach, California 92075, United States
| | - Kara L. Nelson
- Department
of Civil and Environmental Engineering, College of Engineering, University of California, Berkeley, Berkeley, California 94720, United States
- National
Science Foundation Engineering Research Center for Re-inventing the
Nation’s Urban Water Infrastructure (ReNUWIt), Berkeley, California 94720, United States
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8
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Pham C, Medina R, Plumlee MH. Epoxy lining influence on recycled water quality during pipeline transit for potable reuse. Water Environ Res 2022; 94:e10818. [PMID: 36574958 PMCID: PMC10107648 DOI: 10.1002/wer.10818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 10/28/2022] [Accepted: 11/15/2022] [Indexed: 06/09/2023]
Abstract
An epoxy treatment was applied to a pipeline used to convey advanced treated recycled water from a purification facility to a recharge site. The epoxy treatment was applied to prevent further deterioration (corrosion) of the interior cement mortar lining (CML). A soil column study was conducted to evaluate the effect of the epoxy liner on the clogging potential of water before and after conveyance. The clogging potential was represented by differences in the column's relative hydraulic conductivity and water quality, between the treatment plant and injection site, before and after epoxy lining. Hydraulic conductivity of columns at the injection well site declined rapidly before epoxy and improved considerably after epoxy application. Total suspended solids (TSS) and cellular adenosine triphosphate (cATP) median concentrations improved significantly. Before epoxy, TSS increased with pipeline transit from 0.005 to 0.053 (mg/L) compared with 0.009 mg/L after epoxy. Before epoxy, cATP increased from 0.14 to 1.6 pg/ml across pipeline transit compared with 0.37 pg/ml after epoxy. Aluminum and nitrate followed similar trends. Results indicate that epoxy liner reduced the clogging potential of high purity recycled water, likely due to a decrease in particle and biomass load (clogging constituents) accumulated during pipeline transit. PRACTITIONER POINTS: Clogging potential of advanced treated recycled water increases with pipeline transit. Epoxy lining the pipeline used for conveyance reduces the particulate and microbial loading of the highly purified water. Applying epoxy to pipelines used to convey advanced treated recycled water has the dual benefit of infrastructure protection and improving water quality. Reducing particle and microbial load in the advanced treated recycled water can reduce maintenance frequencies and elongate production periods for MAR applications.
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Affiliation(s)
- Christine Pham
- Research and Development DepartmentOrange County Water DistrictAnaheimCaliforniaUSA
| | - Ricardo Medina
- Research and Development DepartmentOrange County Water DistrictAnaheimCaliforniaUSA
- Department of Civil Engineering and Construction ManagementCalifornia State University, NorthridgeNorthridgeCaliforniaUSA
| | - Megan H. Plumlee
- Research and Development DepartmentOrange County Water DistrictFountain ValleyCaliforniaUSA
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9
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Gerrity D, Papp K, Pecson BM. Pathogen Peak "Averaging" in Potable Reuse Systems: Lessons Learned from Wastewater Surveillance of SARS-CoV-2. ACS ES T Water 2022; 2:1863-1870. [PMID: 37566355 PMCID: PMC8791031 DOI: 10.1021/acsestwater.1c00378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 11/19/2021] [Accepted: 11/29/2021] [Indexed: 05/10/2023]
Abstract
This study describes wastewater concentrations of SARS-CoV-2 at seven different sampling locations in Southern Nevada (ranging from 4.2 to 8.7 log10 gc/L) and highlights several key variables affecting those concentrations, including COVID-19 incidence, sample type, and service area population. This information is important for implementing wastewater-based epidemiology, but it also provides insight relevant to the design and regulation of potable reuse systems. Specifically, smaller systems may be more prone to influent concentration spikes that can drive enteric pathogen risk during disease outbreaks. It may be possible to leverage reactor hydraulics to achieve peak "averaging" in these scenarios, although it then becomes important to consider how elevated risks at the lower percentiles potentially offset benefits at the upper percentiles. Informed by SARS-CoV-2 concentration dynamics, the current study simulated relative risk for a hypothetical enteric pathogen. Simulated reactor hydraulics (i.e., dispersion) increased pathogen concentrations by up to 2.6 logs at lower percentiles but also decreased concentrations by up to 1.1 logs at the upper percentiles that sometimes drive public health risk. Collectively, these data highlight the importance of considering outbreak conditions, pathogen spikes, and peak "averaging" in the design and operation of treatment systems and in the development of regulatory frameworks.
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Affiliation(s)
- Daniel Gerrity
- Applied Research and Development Center,
Southern Nevada Water Authority, Las Vegas, Nevada 89193,
United States
| | - Katerina Papp
- Applied Research and Development Center,
Southern Nevada Water Authority, Las Vegas, Nevada 89193,
United States
| | - Brian M. Pecson
- Trussell Technologies,
Inc., Oakland, California 94612, United States
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10
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Chuang YH, Wu KL, Lin WC, Shi HJ. Photolysis of Chlorine Dioxide under UVA Irradiation: Radical Formation, Application in Treating Micropollutants, Formation of Disinfection Byproducts, and Toxicity under Scenarios Relevant to Potable Reuse and Drinking Water. Environ Sci Technol 2022; 56:2593-2604. [PMID: 35025487 DOI: 10.1021/acs.est.1c05707] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Conversion of potable reuse water utilities and drinking water utilities from a low-pressure UV/H2O2 (LPUV/H2O2) advanced oxidation process (AOP) to alternative AOPs in which oxidants can effectively absorb photons and rapidly generate radicals has attracted great interest. Herein, we propose a novel UVA/ClO2 AOP for different water treatment scenarios because of reduced photon absorption by the background matrix and high molar absorptivity for ClO2 at UVA wavelengths. While the photolysis of ClO2 produces •Cl + O2 or •ClO + O(3P) via distinct product channels, we determined the parameters needed to accurately model the loss of oxidants and the formation of byproducts and combined a kinetic model with experimental data to determine quantum yields (Φ). Modeling incorporating the optimized Φ simultaneously predicted oxidant loss and the formation of major products -HOCl, Cl-, and ClO3-. We also systematically investigated the removal of three contaminants exhibiting different radical reactivities, the formation of 35 regulated and unregulated halogenated disinfection byproducts (DBPs), DBP-associated toxicity, and N-acetylcysteine thiol reactivity in synthetic or authentic RO permeates/surface waters treated by different AOPs. The kinetic model developed in this study was used to optimize operating conditions to control undesired products and improve contaminant removal efficiency. The results indicate that UVA/ClO2 can outperform LPUV/H2O2 in terms of electrical energy per order of contaminant degradation, disinfection byproduct formation, and toxicity indices.
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Affiliation(s)
- Yi-Hsueh Chuang
- Institute of Environmental Engineering, National Yang Ming Chiao Tung University, 1001 University Rd., Hsinchu City 30010, Taiwan
| | - Kai-Lin Wu
- Institute of Environmental Engineering, National Yang Ming Chiao Tung University, 1001 University Rd., Hsinchu City 30010, Taiwan
| | - Wei-Chun Lin
- Institute of Environmental Engineering, National Yang Ming Chiao Tung University, 1001 University Rd., Hsinchu City 30010, Taiwan
| | - Hong-Jia Shi
- Institute of Environmental Engineering, National Yang Ming Chiao Tung University, 1001 University Rd., Hsinchu City 30010, Taiwan
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11
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Liu Y, Sim A, Mauter MS. Energy-Optimal Siting of Decentralized Water Recycling Systems. Environ Sci Technol 2021; 55:15343-15350. [PMID: 34714641 DOI: 10.1021/acs.est.1c04708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Decentralized water recycling systems (DWRS) have emerged as a viable option for incrementally augmenting water supply in water-stressed regions, but DWRS are generally more energy-intensive than traditional centralized water treatment systems. When DWRS are deployed incrementally in small batches, the marginal energy intensity (MEI) of water supply quantifies the location-specific energy footprint of centralized water supply and serves as a robust metric measuring the energy implications of replacing centralized supply with DWRS supply. This research develops and applies a MEI-based decision framework that identifies the energy-optimal siting of DWRS to minimize the overall system operational energy consumption given a target fraction of water demand to be met by newly deployed DWRS. In a small benchmark water supply system where the energy intensity of the intended DWRS is 5.3% higher than the current system average energy intensity of centralized supply, we demonstrate that the optimal siting of DWRS to offset 10% of the system-wide water demand reduces the overall system energy consumption by 0.77%. In contrast, the naive and worst-case siting of the same DWRS increases the energy consumption of the overall system by 0.65 and 2.0%, respectively. The proposed MEI-based decision framework is particularly valuable for application in large multi-source systems, where an optimization-based approach is computationally intractable. This study highlights the importance of accounting for both distribution and treatment energy intensity when evaluating new water sources and demonstrates the viability of DWRS as an energy-efficient tool for augmenting water supply.
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Affiliation(s)
- Yang Liu
- Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305, United States
| | - Alison Sim
- Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305, United States
| | - Meagan S Mauter
- Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305, United States
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12
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Tchobanoglous G, Kenny J, Leverenz H. Rationale for constant flow to optimize wastewater treatment and advanced water treatment performance for potable reuse applications. Water Environ Res 2021; 93:1231-1242. [PMID: 33547686 PMCID: PMC8451933 DOI: 10.1002/wer.1531] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/07/2021] [Accepted: 01/25/2021] [Indexed: 05/23/2023]
Abstract
Population growth, the impacts of climate change, and the need for greater water security have made the reuse of wastewater, including potable use, increasingly desirable. As interest in potable reuse of wastewater increases, a variety of processes have been proposed for advanced water treatment following conventional wastewater treatment. In all cases, the operation and performance of advanced water treatment facilities (AWTFs) is improved when the treated wastewater feed is of the highest quality that can be achieved and the advanced water treatment (AWT) processes are operated at a constant flow. One proven method of optimizing the performance of wastewater treatment facilities (WWTFs) is constant flow operation with no extraneous return flows other than internal process recycle flows, such as return settled solids. A number of approaches can be used to achieve constant flow including flow equalization, divided treatment trains, and satellite treatment. The ways in which constant flow wastewater treatment benefits both WWTFs as well as the AWTFs are considered with special emphasis on the ability to achieve predictable log removal credits (LRCs) for specific microorganisms. Actual performance data from constant flow WWTFs are used to illustrate how LRCs are determined. PRACTITIONER POINTS: Constant flow WWTFs should be considered to produce the highest quality secondary effluent for AWT. Flow equalization, divided treatment trains, and satellite treatment can be used to achieve constant flow to optimize wastewater treatment in small and medium size WWTFs. Flow equalization can be used to maximize the amount of wastewater that can be recovered for potable reuse. Important benefits of constant flow for wastewater treatment facilities include economic and operational savings, stable and predictable treatment performance, energy savings, ability to optimize performance for the removal of specific constituents, and the ability to assign pathogen log removal credits (LRCs). Important benefits of constant flow and optimized WWT for AWTFs include economic and operational savings; less pretreatment needed, including energy and chemical usage; elimination of the need to cycle treatment processes; and added factor of safety with respect to the required pathogen LRCs. In large WWTFs, constant flow for AWTFs will typically be achieved by effluent diversion; depending on the effluent quality additional pretreatment may be needed. The design and implementation of WWTFs and AWTFs for potable reuse should be integrated for optimal performance and protection of public health.
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Affiliation(s)
- George Tchobanoglous
- Department of Civil and Environmental EngineeringUniversity of CaliforniaDavisCAUSA
| | | | - Harold Leverenz
- Department of Civil and Environmental EngineeringUniversity of CaliforniaDavisCAUSA
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Sundaram V, Pagilla K. Trace and bulk organics removal during ozone-biofiltration treatment for potable reuse applications. Water Environ Res 2020; 92:430-440. [PMID: 31411786 DOI: 10.1002/wer.1202] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/19/2019] [Accepted: 08/10/2019] [Indexed: 06/10/2023]
Abstract
This study investigated impact of ozone/biological activated carbon (BAC) filtration design and operational parameters on contaminants of emerging concern (CEC) and bulk organics removal over 450 days of operation. Two parallel BAC filters with identical media and influent were maintained, each at a different empty bed contact time of 10 and 20 min. This study captured the CEC removal performance of a BAC filter over an extended operational period after treating 65,000 bed volumes. Ozone system was operated at ozone dose to TOC ratio range of 0.9-2. Biofilter with lower EBCT (10 min) and exhausted media resulted in poor removals of Tris(2-chloroethyl) phosphate (TCEP), perfluorooctanoic acid (PFOA), sucralose, meprobamate, N,N-diethyl-m-toluamide (DEET), and cotinine. Biofilter with higher EBCT (20 min) and remaining adsorptive effects resulted in significant (84% or more) removal of all CECs that were detected in the ozonated effluent. Increasing both ozone dose and BAC EBCT resulted in increased removal of UV absorbance (UVA254 ). The evaluation of impact of ozone:TOC ratio and BAC EBCT on CEC removal, bulk organics (TOC), and UVA254 performed in this study confirmed the importance of these two parameters on overall success of nonreverse osmosis (RO) potable reuse projects. PRACTITIONER POINTS: Ozone-BAC biofiltration is feasible strategy for indirect potable reuse water reclamation. Ozone-BAC empty bed contact time is a critical design parameter. Adsorption and biodegradation are both important mechanisms for trace organic contaminant removal in BAC.
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Affiliation(s)
- Vijay Sundaram
- Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada
| | - Krishna Pagilla
- Department of Civil and Environmental Engineering, University of Nevada, Reno, Nevada
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Onyango LA, Quinn C, Tng KH, Wood JG, Leslie G. A Study of Failure Events in Drinking Water Systems As a Basis for Comparison and Evaluation of the Efficacy of Potable Reuse Schemes. Environ Health Insights 2016; 9:11-8. [PMID: 27053920 PMCID: PMC4818024 DOI: 10.4137/ehi.s31749] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 09/03/2015] [Accepted: 09/08/2015] [Indexed: 06/05/2023]
Abstract
Potable reuse is implemented in several countries around the world to augment strained water supplies. This article presents a public health perspective on potable reuse by comparing the critical infrastructure and institutional capacity characteristics of two well-established potable reuse schemes with conventional drinking water schemes in developed nations that have experienced waterborne outbreaks. Analysis of failure events in conventional water systems between 2003 and 2013 showed that despite advances in water treatment technologies, drinking water outbreaks caused by microbial contamination were still frequent in developed countries and can be attributed to failures in infrastructure or institutional practices. Numerous institutional failures linked to ineffective treatment protocols, poor operational practices, and negligence were detected. In contrast, potable reuse schemes that use multiple barriers, online instrumentation, and operational measures were found to address the events that have resulted in waterborne outbreaks in conventional systems in the past decade. Syndromic surveillance has emerged as a tool in outbreak detection and was useful in detecting some outbreaks; increases in emergency department visits and GP consultations being the most common data source, suggesting potential for an increasing role in public health surveillance of waterborne outbreaks. These results highlight desirable characteristics of potable reuse schemes from a public health perspective with potential for guiding policy on surveillance activities.
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Affiliation(s)
- Laura A. Onyango
- School of Public Health and Community Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Chloe Quinn
- School of Chemical Engineering, University of New South Wales, Sydney, NSW, Australia
| | - Keng H. Tng
- School of Chemical Engineering, University of New South Wales, Sydney, NSW, Australia
| | - James G. Wood
- School of Public Health and Community Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Greg Leslie
- School of Chemical Engineering, University of New South Wales, Sydney, NSW, Australia
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