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Kriss RB, Smith E, Byrd G, Schock M, Edwards MA. Considering a Utility-Centric Framework Based on "Minimum Orthophosphate" Criteria for Mitigation of Elevated Cuprosolvency in Drinking Water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:5606-5615. [PMID: 38470122 DOI: 10.1021/acs.est.4c00583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Gaps in the United States Environmental Protection Agency (US EPA) Lead and Copper Rule (LCR) leave some consumers and their pets vulnerable to high cuprosolvency in drinking water. This study seeks to help proactive utilities who wish to mitigate cuprosolvency problems through the addition of orthophosphate corrosion inhibitors. The minimum doses of orthophosphate necessary to achieve acceptable cuprosolvency in relatively new copper pipe were estimated as a function of alkalinity via linear regressions for the 90th, 95th, and 100th percentile copper tube segments (R2 > 0.98, n = 4). Orthophosphate was very effective at reducing cuprosolvency in the short term but, in some cases, resulted in higher long-term copper concentrations than the corresponding condition without orthophosphate. Alternatives to predicting "long-term" results for copper tubes using simpler bench tests starting with fresh Cu(OH)2 solids showed promise but would require further vetting to overcome limitations such as maintaining water chemistry and orthophosphate residuals and to ensure comparability to results using copper tube.
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Affiliation(s)
- Rebecca B Kriss
- Virginia Polytechnic and State University, Civil and Environmental Engineering, 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Emily Smith
- Virginia Polytechnic and State University, Civil and Environmental Engineering, 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Grace Byrd
- Virginia Polytechnic and State University, Civil and Environmental Engineering, 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | | | - Marc A Edwards
- Virginia Polytechnic and State University, Civil and Environmental Engineering, 418 Durham Hall, Blacksburg, Virginia 24061, United States
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2
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Devine C, Triantafyllidou S. A literature review of bench top and pilot lead corrosion assessment studies. AWWA WATER SCIENCE 2023; 5:10.1002/aws2.1324. [PMID: 37538099 PMCID: PMC10395321 DOI: 10.1002/aws2.1324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 01/23/2023] [Indexed: 08/05/2023]
Abstract
Bench top and pilot lead corrosion studies are gaining more interest, considering revisions and upcoming improvements to the Lead and Copper Rule. This literature review identified studies ranging from simpler month(s)-long bench top dump-and-fill stagnant water tests (coupon tests/standing pipe tests) to more complicated year(s)-long intermittent flow pilot studies (recirculating pipe loops/once through pipe rigs). With increasing complexity in design and operation, studies more closely approximated real plumbing conditions (e.g., by incorporating harvested lead pipes and intermittent flow regimes) at increased cost, footprint, and duration. Comparison of bench top and pilot designs (in terms of lead test piece age/dimensions/configuration/replicates, study duration, sample collection, and other factors) can assist drinking water utilities, consultants, academics, and others to select a design that matches their needs and constraints. No matter the choice, surrogate systems cannot replace actual system water testing and are best complemented by other corrosion assessment tools.
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Affiliation(s)
- Christina Devine
- Oak Ridge Institute for Science and Education Postdoctoral
Fellow at the U.S. Environmental Protect Agency, Office of Research and Development,
Center for Environmental Solutions & Emergency Response, Water Infrastructure
Division, Drinking Water Quality Branch, Cincinnati, Ohio, USA
| | - Simoni Triantafyllidou
- U.S. Environmental Protect Agency, Office of Research and
Development, Center for Environmental Solutions & Emergency Response, Water
Infrastructure Division, Drinking Water Quality Branch, Cincinnati, Ohio, USA
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3
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Spencer-Williams I, Balangoda A, Dabundo R, Elliott E, Haig SJ. Exploring the Impacts of Full-Scale Distribution System Orthophosphate Corrosion Control Implementation on the Microbial Ecology of Hydrologically Connected Urban Streams. Microbiol Spectr 2022; 10:e0215822. [PMID: 36321898 PMCID: PMC9769763 DOI: 10.1128/spectrum.02158-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 10/04/2022] [Indexed: 12/24/2022] Open
Abstract
Many cities across the nation are plagued by lead contamination in drinking water. As such, many drinking water utilities have undertaken lead service line (LSL) replacement to prevent further lead contamination. However, given the urgency of lead mitigation, and the socioeconomic challenges associated with LSL replacement, cities have used phosphate-based corrosion inhibitors (i.e., orthophosphate) alongside LSL replacement. While necessary to ensure public health protection from lead contamination, the addition of orthophosphate into an aging and leaking drinking water system may increase the concentration of phosphate leaching into urban streams characterized by century-old failing water infrastructure. Such increases in phosphate availability may cascade into nutrient and microbial community composition shifts. The purpose of this study was to determine how this occurs and to understand whether full-scale distribution system orthophosphate addition impacts the microbial ecology of urban streams. Through monthly collection of water samples from five urban streams before and after orthophosphate addition, significant changes in microbial community composition (16S rRNA amplicon sequencing) and in the relative abundance of typical freshwater taxa were observed. In addition, key microbial phosphorus and nitrogen metabolism genes (e.g., two component regulatory systems) were predicted to change via BugBase. No significant differences in the absolute abundances of total bacteria, Cyanobacteria, and "Candidatus Accumulibacter" were observed. Overall, the findings from this study provide further evidence that urban streams are compromised by unintentional hydrologic connections with drinking water infrastructure. Moreover, our results suggest that infiltration of phosphate-based corrosion inhibitors can impact urban streams and have important, as-yet-overlooked impacts on urban stream microbial communities. IMPORTANCE Elevated lead levels in drinking water supplies are a public health risk. As such, it is imperative for cities to urgently address lead contamination from aging drinking water supplies by way of lead service line replacements and corrosion control methods. However, when applying corrosion control methods, it is also important to consider the chemical and microbiological effects that can occur in natural settings, given that our water infrastructure is aging and more prone to leaks and breaks. Here, we examine the impacts on the microbial ecology of five urban stream systems before and after full-scale distribution system orthophosphate addition. Overall, the results suggest that infiltration of corrosion inhibitors may impact microbial communities; however, future work should be done to ascertain the true impact to protect both public and environmental health.
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Affiliation(s)
- Isaiah Spencer-Williams
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Anusha Balangoda
- Department of Geology and Environmental Science, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Richard Dabundo
- Department of Geology and Environmental Science, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Emily Elliott
- Department of Geology and Environmental Science, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Sarah-Jane Haig
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Environmental and Occupational Health, School of Public Health, University of Pittsburgh, Pennsylvania, USA
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4
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Konadu-Amoah B, Hu R, Ndé-Tchoupé AI, Gwenzi W, Noubactep C. Metallic iron (Fe 0)-based materials for aqueous phosphate removal: A critical review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 315:115157. [PMID: 35526394 DOI: 10.1016/j.jenvman.2022.115157] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 04/06/2022] [Accepted: 04/22/2022] [Indexed: 06/14/2023]
Abstract
The discharge of excessive phosphate from wastewater sources into the aquatic environment has been identified as a major environmental threat responsible for eutrophication. It has become essential to develop efficient but affordable techniques to remove excess phosphate from wastewater before discharging into freshwater bodies. The use of metallic iron (Fe0) as a reactive agent for aqueous phosphate removal has received a wide attention. Fe0 in-situ generates positively charged iron corrosion products (FeCPs) at pH > 4.5, with high binding affinity for anionic phosphate. This study critically reviews the literature that focuses on the utilization of Fe0-based materials for aqueous phosphate removal. The fundamental science of aqueous iron corrosion and historical background of the application of Fe0 for phosphate removal are elucidated. The main mechanisms for phosphate removal are identified and extensively discussed based on the chemistry of the Fe0/H2O system. This critical evaluation confirms that the removal process is highly influenced by several operational factors including contact time, Fe0 type, influent geochemistry, initial phosphate concentration, mixing conditions, and pH value. The difficulty in comparing independent results owing to diverse experimental conditions is highlighted. Moreover, contemporary research in progress including Fe0/oxidant systems, nano-Fe0 application, Fe0 material selection, desorption studies, and proper design of Fe0-based systems for improved phosphate removal have been discussed. Finally, potential strategies to close the loop in Fe0-based phosphate remediation systems are discussed. This review presents a science-based guide to optimize the efficient design of Fe0-based systems for phosphate removal.
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Affiliation(s)
- Bernard Konadu-Amoah
- School of Earth Science and Engineering, Hohai University, Fo Cheng Xi Road 8, Nanjing, 211100, China.
| | - Rui Hu
- School of Earth Science and Engineering, Hohai University, Fo Cheng Xi Road 8, Nanjing, 211100, China.
| | - Arnaud Igor Ndé-Tchoupé
- School of Earth Science and Engineering, Hohai University, Fo Cheng Xi Road 8, Nanjing, 211100, China.
| | - Willis Gwenzi
- Biosystems and Environmental Engineering Research Group, Department of Agricultural and Biosystems Engineering, University of Zimbabwe, P.O. Box MP167, Mount Pleasant, Harare, Zimbabwe.
| | - Chicgoua Noubactep
- School of Earth Science and Engineering, Hohai University, Fo Cheng Xi Road 8, Nanjing, 211100, China; Centre for Modern Indian Studies (CeMIS), University of Göttingen, Waldweg 26, 37073, Göttingen, Germany; Department of Water and Environmental Science and Engineering, Nelson Mandela African Institution of Science and Technology, Arusha P.O. Box 447, Tanzania; Faculty of Science and Technology, Campus of Banekane, Université des Montagnes, P.O. Box 208, Bangangté, Cameroon.
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5
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Trueman BF, Bleasdale-Pollowy A, Locsin JA, Bennett JL, Krkošek WH, Gagnon GA. Seasonal Lead Release into Drinking Water and the Effect of Aluminum. ACS ES&T WATER 2022; 2:710-720. [PMID: 35603038 PMCID: PMC9112280 DOI: 10.1021/acsestwater.1c00320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 04/06/2022] [Accepted: 04/07/2022] [Indexed: 06/15/2023]
Abstract
Monitoring lead in drinking water is important for public health, but seasonality in lead concentrations can bias monitoring programs if it is not understood and accounted for. Here, we describe an apparent seasonal pattern in lead release into orthophosphate-treated drinking water, identified through point-of-use sampling at sites in Halifax, Canada, with various sources of lead. Using a generalized additive model, we extracted the seasonally varying components of time series representing a suite of water quality parameters and we identified aluminum as a correlate of lead. To investigate aluminum's role in lead release, we modeled the effect of variscite (AlPO4·2H2O) precipitation on lead solubility, and we evaluated the effects of aluminum, temperature, and orthophosphate concentration on lead release from new lead coupons. At environmentally relevant aluminum and orthophosphate concentrations, variscite precipitation increased predicted lead solubility by decreasing available orthophosphate. Increasing the aluminum concentration from 20 to 500 μg L-1 increased lead release from coupons by 41% and modified the effect of orthophosphate, rendering it less effective. We attributed this to a decrease in the concentration of soluble (<0.45 μm) phosphorus with increasing aluminum and an accompanying increase in particulate lead and phosphorus (>0.45 μm).
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Affiliation(s)
- Benjamin F. Trueman
- Centre
for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington Street, Halifax, Nova Scotia B3H
4R2, Canada
| | - Aaron Bleasdale-Pollowy
- Centre
for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington Street, Halifax, Nova Scotia B3H
4R2, Canada
| | - Javier A. Locsin
- Centre
for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington Street, Halifax, Nova Scotia B3H
4R2, Canada
| | - Jessica L. Bennett
- Centre
for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington Street, Halifax, Nova Scotia B3H
4R2, Canada
| | - Wendy H. Krkošek
- Halifax
Water, 450 Cowie Hill
Road, Halifax, Nova Scotia, P.O. Box 8388, B3K 5M1, Canada
| | - Graham A. Gagnon
- Centre
for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington Street, Halifax, Nova Scotia B3H
4R2, Canada
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6
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Li B, Trueman BF, Munoz S, Locsin JM, Gagnon GA. Impact of sodium silicate on lead release and colloid size distributions in drinking water. WATER RESEARCH 2021; 190:116709. [PMID: 33341036 DOI: 10.1016/j.watres.2020.116709] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 11/20/2020] [Accepted: 11/28/2020] [Indexed: 06/12/2023]
Abstract
Sodium silicates have been used in drinking water treatment for decades as sequestrants and corrosion inhibitors. For the latter purpose they are poorly understood, which presents a potential public health risk. We investigated a common sodium silicate formulation as a treatment for lead release and compared it to orthophosphate, a well-established lead corrosion control treatment. We also compared the size distributions of colloids generated in silicate and orthophosphate-treated systems using field flow fractionation with multielement detection. At a moderate dose of 24 mg SiO2/L, sodium silicate yielded a median lead release of 398 µg/L, while orthophosphate yielded 67 µg Pb/L. At an elevated dose of 48 mg SiO2/L, sodium silicate dispersed corrosion scale in cast iron pipe sections and lead service lines, resulting in a substantial release of colloidal iron and lead. In the silicate-treated system, a silicon-rich coating occurred at the lead-water interface, but lead carbonate remained the major corrosion product and appeared to control lead levels. These data suggest that, as a corrosion control treatment for lead, sodium silicate is inferior to orthophosphate in circumneutral pH water with low alkalinity. And, as with polyphosphate, excess silicate can be highly detrimental to controlling lead release.
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Affiliation(s)
- Bofu Li
- Centre for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington St., Halifax, Nova Scotia, Canada B3H 4R2
| | - Benjamin F Trueman
- Centre for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington St., Halifax, Nova Scotia, Canada B3H 4R2
| | - Sebastian Munoz
- Centre for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington St., Halifax, Nova Scotia, Canada B3H 4R2
| | - Javier M Locsin
- Centre for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington St., Halifax, Nova Scotia, Canada B3H 4R2
| | - Graham A Gagnon
- Centre for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington St., Halifax, Nova Scotia, Canada B3H 4R2.
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7
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Lytle DA, Schock MR, Leo J, Barnes B. A Model for Estimating the Impact of Orthophosphate on Copper in Water. ACTA ACUST UNITED AC 2018; 110:E1-E15. [PMID: 32636529 DOI: 10.1002/awwa.1109] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The nature of copper phosphate minerals in drinking water distribution systems has remained largely unsolved despite being an important link to reducing cuprosolvency. Chemical equilibrium modeling has also largely failed to accurately predict soluble copper in the presence of orthophosphate. The objective of this work was to develop and validate an empirical copper solubility model that considered pH, dissolved inorganic carbon (DIC), and orthophosphate from a series of bench-scale copper precipitation experiments. An empirical model was constructed that allows for the determination of copper levels in a system given pH, DIC, and orthophosphate data. The predictive reliability of this model was assessed by evaluating a collection of cuprosolvency data from two decades of research and field observations and water treatment reports. The tests yielded a firm correlation between predicted and observed copper levels attested by a regression coefficient of 0.86 for a total of 851 observations.
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Affiliation(s)
- Darren A Lytle
- US Environmental Protection Agency, ORD, NRMRL, WSWRD, TTEB, Cincinnati, Ohio
| | - Michael R Schock
- US Environmental Protection Agency, ORD, NRMRL, WSWRD, TTEB, Cincinnati, Ohio
| | - Jordan Leo
- College of Engineering and Applied Sciences, Chemical Engineering, University of Cincinnati, Cincinnati, Ohio
| | - Benjamin Barnes
- Department of Natural Resources, Chemistry, University of Maryland Eastern Shore, Princess Anne, Md
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8
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Shen Y, Huang PC, Huang C, Sun P, Monroy GL, Wu W, Lin J, Espinosa-Marzal RM, Boppart SA, Liu WT, Nguyen TH. Effect of divalent ions and a polyphosphate on composition, structure, and stiffness of simulated drinking water biofilms. NPJ Biofilms Microbiomes 2018; 4:15. [PMID: 30038792 PMCID: PMC6052100 DOI: 10.1038/s41522-018-0058-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Revised: 05/24/2018] [Accepted: 06/01/2018] [Indexed: 02/04/2023] Open
Abstract
The biofilm chemical and physical properties in engineered systems play an important role in governing pathogen transmission, fouling facilities, and corroding metal surfaces. Here, we investigated how simulated drinking water biofilm chemical composition, structure, and stiffness responded to the common scale control practice of adjusting divalent ions and adding polyphosphate. Magnetomotive optical coherence elastography (MM-OCE), a tool developed for diagnosing diseased tissues, was used to determine biofilm stiffness in this study. MM-OCE, together with atomic force microscopy (AFM), revealed that the biofilms developed from a drinking water source with high divalent ions were stiffer compared to biofilms developed either from the drinking water source with low divalent ions or the water containing a scale inhibitor (a polyphosphate). The higher stiffness of biofilms developed from the water containing high divalent ions was attributed to the high content of calcium carbonate, suggested by biofilm composition examination. In addition, by examining the biofilm structure using optical coherence tomography (OCT), the highest biofilm thickness was found for biofilms developed from the water containing the polyphosphate. Compared to the stiff biofilms developed from the water containing high divalent ions, the soft and thick biofilms developed from the water containing polyphosphate will be expected to have higher detachment under drinking water flow. This study suggested that water chemistry could be used to predict the biofilm properties and subsequently design the microbial safety control strategies. A variety of analytical techniques are revealing the complex influences of ions in drinking water supplies on the structure of biofilms. Such biofilms often contaminate water supply pipes and machinery. Yun Shen and colleagues at the University of Illinois at Urbana-Champaign in the USA investigated the effects of ions with a double positive charge – ‘divalent cations’ – and polyphosphate ions. Divalent cations, especially calcium and magnesium ions, are abundant in drinking water in many regions, promoting the formation of limescale deposits. Polyphosphates are commonly added to water supplies to reduce limescale formation, inhibit corrosion and discourage biofilm formation. The research revealed that divalent cations increase biofilm stiffness, while polyphosphates promote softer but thicker biofilms that are more easily removed. The results will help optimize water treatment procedures to control both microbial contamination and limescale problems.
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Affiliation(s)
- Yun Shen
- 1Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL USA.,4Present Address: University of Michigan, 1351 Beal Ave., 219 EWRE Bldg, Ann Arbor, MI 48109-2125 USA
| | - Pin Chieh Huang
- 2Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL USA
| | - Conghui Huang
- 1Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL USA
| | - Peng Sun
- 1Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL USA
| | - Guillermo L Monroy
- 2Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL USA
| | - Wenjing Wu
- 1Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL USA
| | - Jie Lin
- 1Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL USA
| | - Rosa M Espinosa-Marzal
- 1Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL USA
| | - Stephen A Boppart
- 2Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL USA.,3Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL USA
| | - Wen-Tso Liu
- 1Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL USA
| | - Thanh H Nguyen
- 1Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL USA
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9
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Jereb G, Poljšak B, Eržen I. Contribution of Drinking Water Softeners to Daily Phosphate Intake in Slovenia. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2017; 14:E1186. [PMID: 28984825 PMCID: PMC5664687 DOI: 10.3390/ijerph14101186] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Revised: 10/03/2017] [Accepted: 10/04/2017] [Indexed: 12/14/2022]
Abstract
The cumulative phosphate intake in a typical daily diet is high and, according to several studies, already exceeds recommended values. The exposure of the general population to phosphorus via drinking water is generally not known. One of the hidden sources of phosphorus in a daily diet is sodium polyphosphate, commonly used as a drinking water softener. In Slovenia, softening of drinking water is carried out exclusively within the internal (household) drinking water supply systems to prevent the accumulation of limescale. The aim of the study was to determine the prevalence of sodium phosphates in the drinking water in Slovenia in different types of buildings, to determine residents' awareness of the presence of chemical softeners in their drinking water, and to provide an exposure assessment on the phosphorus intake from drinking water. In the current study, the presence of phosphates in the samples of drinking water was determined using a spectrophotometric method with ammonium molybdate. In nearly half of the samples, the presence of phosphates as water softeners was confirmed. The measured concentrations varied substantially from 0.2 mg PO4/L to 24.6 mg PO4/L. Nearly 70% of the respondents were not familiar with the exact data on water softening in their buildings. It follows that concentrations of added phosphates should be controlled and the consumers should be informed of the added chemicals in their drinking water. The health risks of using sodium polyphosphate as a drinking water softener have not been sufficiently investigated and assessed. It is highly recommended that proper guidelines and regulations are developed and introduced to protect human health from adverse effects of chemicals in water intended for human consumption.
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Affiliation(s)
- Gregor Jereb
- Faculty of Health Sciences, University of Ljubljana, Zdravstvena pot 5, 1000 Ljubljana, Slovenia.
| | - Borut Poljšak
- Faculty of Health Sciences, University of Ljubljana, Zdravstvena pot 5, 1000 Ljubljana, Slovenia.
| | - Ivan Eržen
- Department of Environmental Health, National Institute of Public Health, Trubarjeva 2, 1000 Ljubljana, Slovenia.
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10
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Kogo A, Payne SJ, Andrews RC. Comparison of three corrosion inhibitors in simulated partial lead service line replacements. JOURNAL OF HAZARDOUS MATERIALS 2017; 329:211-221. [PMID: 28178636 DOI: 10.1016/j.jhazmat.2017.01.039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 01/16/2017] [Accepted: 01/21/2017] [Indexed: 06/06/2023]
Abstract
Partial lead service line replacements (PLSLR) were simulated using five recirculating pipe loops treated with either zinc orthophosphate (1mg/L as P), orthophosphate (1mg/L as P) or sodium silicate (10mg/L). Two pipe loops served as inhibitor-free (Pb-Cu) and galvanic free (Pb-PVC) controls. Changes in water quality (CSMR [0.2 or 1], conductivity [330mS/cm or 560mS/cm], chlorine [1.4mg/L]) were not observed to provide a significant impact on lead or copper release, although galvanic corrosion was shown to be a driving factor. Generally, both orthophosphate and zinc orthophosphate provided better corrosion control for both total and dissolved lead (30min, 6h, 65h) and copper (30min, 6h), when compared to either the inhibitor-free control or the sodium silicate treated system. This work highlights the importance of understanding the complex interplay of corrosion inhibitors on particulate and dissolved species when considering both lead and copper.
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Affiliation(s)
- Aki Kogo
- Department of Civil Engineering, University of Toronto,35 St. George Street, Toronto, ON M5S 1A4, Canada
| | - Sarah Jane Payne
- Department of Civil Engineering, University of Toronto,35 St. George Street, Toronto, ON M5S 1A4, Canada.
| | - Robert C Andrews
- Department of Civil Engineering, University of Toronto,35 St. George Street, Toronto, ON M5S 1A4, Canada
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11
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Masters S, Parks J, Atassi A, Edwards MA. Distribution system water age can create premise plumbing corrosion hotspots. ENVIRONMENTAL MONITORING AND ASSESSMENT 2015; 187:559. [PMID: 26251058 DOI: 10.1007/s10661-015-4747-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 07/14/2015] [Indexed: 06/04/2023]
Abstract
Cumulative changes in chemical and biological properties associated with higher "water age" in distribution systems may impact water corrosivity and regulatory compliance with lead and copper action levels. The purpose of this study was to examine the effects of water age and chemistry on corrosivity of various downstream premise plumbing pipe materials and configurations using a combination of controlled laboratory studies and a field survey. Examination of lead pipe, copper pipe with lead solder, and leaded brass materials in a replicated lab rig simulating premise plumbing stagnation events indicated that lead or copper release could increase as much as ∼440 % or decrease as much as 98 % relative to water treatment plant effluent. In field studies at five utilities, trends in lead and copper release were highly dependent on circumstance; for example, lead release increased with water age in 13 % of cases and decreased with water age in 33 % of conditions tested. Levels of copper in the distribution system were up to 50 % lower and as much as 30 % higher relative to levels at the treatment plant. In many cases, high-risks of elevated lead and copper did not co-occur, demonstrating that these contaminants will have to be sampled separately to identify "worst case" conditions for human exposure and monitoring.
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Affiliation(s)
- Sheldon Masters
- Via Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, 24061, USA,
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12
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Clark B, Masters S, Edwards M. Profile sampling to characterize particulate lead risks in potable water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:6836-43. [PMID: 24865841 DOI: 10.1021/es501342j] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Traditional lead (Pb) profiling, or collecting sequential liters of water that flow from a consumer tap after a stagnation event, has recently received widespread use in understanding sources of Pb in drinking water and risks to consumer health, but has limitations in quantifying particulate Pb risks. A new profiling protocol was developed in which a series of traditional profiles are collected from the same tap at escalating flow rates. The results revealed marked differences in risks of Pb exposure from one consumer home to another as a function of flow rate, with homes grouped into four risk categories with differing flushing requirements and public education to protect consumers. On average, Pb concentrations detected in water at high flow without stagnation were at least three to four times higher than in first draw samples collected at low flow with stagnation, demonstrating a new "worst case" lead release scenario, contrary to the original regulatory assumption that stagnant, first draw samples contain the highest lead concentrations. Testing also revealed that in some cases water samples with visible particulates had much higher Pb than samples without visible particulates, and tests of different sample handling protocols confirmed that some EPA-allowed methods would not quantify as much as 99.9% of the Pb actually present (avg. 27% of Pb not quantified).
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Affiliation(s)
- Brandi Clark
- Virginia Tech , Civil and Environmental Engineering, 418 Durham Hall, Blacksburg, Virginia 24061, United States
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Du K, Zhou Y, Wang L, Wang Y. Fluorescent-tagged no phosphate and nitrogen free calcium phosphate scale inhibitor for cooling water systems. J Appl Polym Sci 2009. [DOI: 10.1002/app.30213] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
14
|
Naderi R, Attar M. Electrochemical assessing corrosion inhibiting effects of zinc aluminum polyphosphate (ZAPP) as a modified zinc phosphate pigment. Electrochim Acta 2008. [DOI: 10.1016/j.electacta.2008.03.029] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
15
|
|
16
|
Hozalski RM, Esbri-Amador E, Chen CF. Comparison of stannous chloride and phosphate for lead corrosion control. ACTA ACUST UNITED AC 2005. [DOI: 10.1002/j.1551-8833.2005.tb10847.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
17
|
Cantor AF, Park JK, Vaiyavatjamai P. Effect of chlorine on corrosion in Drinking Water Systems. ACTA ACUST UNITED AC 2003. [DOI: 10.1002/j.1551-8833.2003.tb10366.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
18
|
|
19
|
|
20
|
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