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Hatam F, Blokker M, Doré E, Prévost M. Reduction in water consumption in premise plumbing systems: Impacts on lead concentration under different water qualities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 879:162975. [PMID: 36965725 DOI: 10.1016/j.scitotenv.2023.162975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 03/14/2023] [Accepted: 03/17/2023] [Indexed: 05/17/2023]
Abstract
Water conservation measures are increasing in response to regulatory requirements addressing the need for lower environmental footprint and in response to water shortages. In households with lead service lines (LSLs), lowering consumption can adversely impact lead release as it will increase stagnation. Using a lead dissolution model and data from extensive pilot studies on excavated LSLs, the impact of adaptation to different water conservation strategies on dissolved lead contamination at the kitchen tap is assessed under three water qualities and three LSL lengths (3, 14 and 30 m) using hydraulic and water quality modelling. Consumers' behavioural variability is also assessed based on integration of EPANET and results of the stochastic water demand model SIMDEUM. Demand reduction increased the dissolved lead concentrations (Pbdiss) at the end of the LSL with mean values ranging from 28.4 to 63.3 μg/L (without corrosion control) and from 4.6 to 9.9 μg/L with corrosion control (addition of orthophosphate and pH adjustment). Adding orthophosphate (1 mg P/L) to the water reduces the mean Pbdiss values at the kitchen tap from 7.1 μg/L to 1.2 μg/L for a high water demand scenario and from 31.2 to 4.9 μg/L for a low water demand scenario. Finally, the Integrated Exposure Uptake Biokinetic (IEUBK) model is used to predict the potential blood lead levels (BLLs) for children aged 0-84 months. Results showed that the orthophosphate addition of only 1 mg P/L can significantly decrease the proportion of children with a BLL >5 μg/dL, from 82 % to 17 %, under the most extreme water conservation scenario studied, using the 90th percentile of Pbdiss concentrations during usage at kitchen tap. Wide variations of Pbdiss concentrations at the kitchen tap were calculated at times of use over a week (up to 155 μg/L in lower demand scenarios, without corrosion control) showing evident limitations of single random daytime sampling.
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Affiliation(s)
- Fatemeh Hatam
- Industrial Chair on Drinking Water, Department of Civil, Geological and Mining Engineering, Polytechnique Montréal, CP 6079, Succ. Centre-ville, Montréal, QC H3C 3A7, Canada.
| | - Mirjam Blokker
- KWR Watercycle Research Institute, Groningenhaven 7, 3433 PE Nieuwegein, the Netherlands
| | - Evelyne Doré
- Industrial Chair on Drinking Water, Department of Civil, Geological and Mining Engineering, Polytechnique Montréal, CP 6079, Succ. Centre-ville, Montréal, QC H3C 3A7, Canada
| | - Michèle Prévost
- Industrial Chair on Drinking Water, Department of Civil, Geological and Mining Engineering, Polytechnique Montréal, CP 6079, Succ. Centre-ville, Montréal, QC H3C 3A7, Canada
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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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Succar A, Lefebvre X, Prévost M, Bédard E, Robert E. Characterization of the aerosol produced from an aerated jet. WATER RESEARCH 2023; 229:119432. [PMID: 36495852 DOI: 10.1016/j.watres.2022.119432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 11/15/2022] [Accepted: 11/25/2022] [Indexed: 06/17/2023]
Abstract
Faucet aerators that form aerated water jets generate aerosols, which can constitute a risk of infection if the water is contaminated, particularly for vulnerable individuals near the sink. In this study, we characterize the size and trajectory of water droplets produced from an aerated jet. The detected particle diameter ranged from 3 to 150μm. The concentration of droplets in the air varied from near-zero to a maximum of 2×1011particles/m3, depending on the location relative to the jet. We found four relevant categories of droplets based on their trajectories following their emission at the jet's free surface: particles with inertia high enough to escape the immediate vicinity of the jet (category 1), particles moving towards the jet (category 2), particles drawn into the aerator, which only included particles with a diameter smaller than 50μm (category 3), and particles with a near-vertical trajectory (category 4). Tracing category 1 particles to their generation location on the water interface shows a higher emission rate near the aerator. Finally, we employ a numerical model to compute the subsequent trajectories of droplets detected at the limits of the sampled domain. We find that particles whose diameter is smaller than 55μm completely dry and become airborne. Larger droplets deposit within a radius of 7cm around the jet, assuming a surface is located 20cm below the aerator tip. These results increase the fundamental understanding of the emission mechanisms of droplets in aerated jets and their fate in the sink environment.
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Affiliation(s)
- Antonella Succar
- Department of Mechanical Engineering, Polytechnique Montréal, Montréal, QC, Canada.
| | - Xavier Lefebvre
- Department of Mechanical Engineering, Polytechnique Montréal, Montréal, QC, Canada
| | - Michèle Prévost
- Industrial Chair on Drinking Water, Department of Civil, Geological and Mining Engineering, Polytechnique Montréal, Montréal, QC, Canada
| | - Emilie Bédard
- Department of Civil, Geological and Mining Engineering, Polytechnique Montréal, Montréal, QC, Canada
| | - Etienne Robert
- Department of Mechanical Engineering, Polytechnique Montréal, Montréal, QC, Canada
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4
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Mansur S, Othman MHD, Ismail NJ, Sheikh Abdul Kadir SH, Puteh MH, Abdullah H, Jaafar J, Rahman MA, Kusworo TD, Ismail AF, Ahmad AL. Hybrid Inorganic Organic PSF/Hap Dual-Layer Hollow Fibre Membrane for the Treatment of Lead Contaminated Water. MEMBRANES 2023; 13:170. [PMID: 36837673 PMCID: PMC9965034 DOI: 10.3390/membranes13020170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/20/2023] [Accepted: 01/28/2023] [Indexed: 06/18/2023]
Abstract
Lead (Pb) exposure can be harmful to public health, especially through drinking water. One of the promising treatment methods for lead contaminated water is the adsorption-filtration method. To ensure the cost-effectiveness of the process, naturally derived adsorbent shall be utilised. In this study, hydroxyapatite particles, Ca10(PO4)6(OH)2 (HAP) derived from waste cockle shell, were incorporated into the outer layer of polysulfone/HAP (PSf/HAP) dual-layer hollow fibre (DLHF) membrane to enhance the removal of lead from the water source due to its hydrophilic nature and excellent adsorption capacity. The PSf/HAP DLHF membranes at different HAP loadings in the outer layer (0, 10, 20, 30 and 40 wt%) were fabricated via the co-extrusion phase inversion technique. The performance of the DLHF membranes was evaluated in terms of pure water flux, permeability and adsorption capacity towards lead. The results indicated that the HAP was successfully incorporated into the outer layer of the membrane, as visibly confirmed by microscopic analysis. The trend was towards an increase in pure water flux, permeability and lead adsorption capacity as the HAP loading increased to the optimum loading of 30 wt%. The optimized DLHF membrane displayed a reduced water contact angle by 95%, indicating its improved surface hydrophilicity, which positively affects the pure water flux and permeability of the membrane. Furthermore, the DLHF membrane possessed the highest lead adsorption capacity, 141.2 mg/g. The development of a hybrid inorganic-organic DLHF membrane via the incorporation of the naturally derived HAP in the outer layer is a cost-effective approach to treat lead contaminated water.
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Affiliation(s)
- Sumarni Mansur
- Advanced Membrane Technology Research Centre (AMTEC), Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia, Johor Bahru 81310, Johor, Malaysia
| | - Mohd Hafiz Dzarfan Othman
- Advanced Membrane Technology Research Centre (AMTEC), Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia, Johor Bahru 81310, Johor, Malaysia
| | - Nurul Jannah Ismail
- Advanced Membrane Technology Research Centre (AMTEC), Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia, Johor Bahru 81310, Johor, Malaysia
| | - Siti Hamimah Sheikh Abdul Kadir
- Laboratory and Forensics (I-PPerForM), Institute of Pathology, Faculty of Medicine, Universiti Teknologi Mara (UiTM), Cawangan Selangor, Sungai Buloh 47000, Selangor, Malaysia
| | - Mohd Hafiz Puteh
- School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, Skudai 81310, Johor, Malaysia
| | - Huda Abdullah
- Department of Electrical, Electronic & Systems Engineering, Faculty of Engineering & Built Environment, The National University of Malaysia, Bangi 43600, Selangor, Malaysia
| | - Juhana Jaafar
- Advanced Membrane Technology Research Centre (AMTEC), Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia, Johor Bahru 81310, Johor, Malaysia
| | - Mukhlis A. Rahman
- Advanced Membrane Technology Research Centre (AMTEC), Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia, Johor Bahru 81310, Johor, Malaysia
| | - Tutuk Djoko Kusworo
- Department of Chemical Engineering, Faculty of Engineering Diponegoro University, Semarang 50275, Indonesia
| | - Ahmad Fauzi Ismail
- Advanced Membrane Technology Research Centre (AMTEC), Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia, Johor Bahru 81310, Johor, Malaysia
| | - Abdul Latif Ahmad
- School of Chemical Engineering, Universiti Sains Malaysia, Engineering Campus, Nibong Tebal 14300, Pulau Pinang, Malaysia
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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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Lobo GP, Kalyan B, Gadgil AJ. Electrochemical deposition of amorphous aluminum oxides on lead pipes to prevent lead leaching into the drinking water. JOURNAL OF HAZARDOUS MATERIALS 2022; 423:127195. [PMID: 34544000 DOI: 10.1016/j.jhazmat.2021.127195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 09/06/2021] [Accepted: 09/08/2021] [Indexed: 06/13/2023]
Abstract
Over 5000 public drinking water systems in the US are out of compliance with the Lead and Copper Rule. Lead leaching from lead pipes is limited by the solubility of a naturally occurring scale. Changes in water quality may cause this scale to become more soluble, releasing lead into the drinking water. We propose a novel electrochemical method to prevent lead leaching from lead pipes. In this method, an aluminum wire and an alkaline phosphate electrolyte are inserted into the pipes. The pipes are then anodized for 2 h by using an external power supply, resulting in the electrodeposition of an insoluble aluminum oxide layer on top of the preexisting scale. This technology was tested on lead pipes from the EBMUD water distribution systems located in Berkeley, CA, using recirculating synthetic and actual tap water for 120 days. The untreated pipes leached an average of 23 ppb and 38 ppb of lead respectively, when using free chlorine and monochloramine as disinfection residuals. In contrast, the treated pipes leached 3 ppb and 5 ppb respectively. These results suggest that the proposed treatment has the potential to prevent lead leaching regardless of the disinfection residual and thus should be further explored in a field trial.
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Affiliation(s)
- G P Lobo
- Department of Civil and Environmental Engineering, University of California, Berkeley 94720, United States
| | - B Kalyan
- Department of Civil and Environmental Engineering, University of California, Berkeley 94720, United States
| | - A J Gadgil
- Department of Civil and Environmental Engineering, University of California, Berkeley 94720, United States.
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Wahman DG, Pinelli MD, Schock MR, Lytle DA. Theoretical equilibrium lead(II) solubility revisited: Open source code and practical relationships. AWWA WATER SCIENCE 2021; 3. [PMID: 34938979 DOI: 10.1002/aws2.1250] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A theoretical equilibrium lead(II) (Pb(II)) solubility model coded in Fortran (LEADSOL) was updated and implemented in open source R code, verified against LEADSOL output, and used to simulate theoretical equilibrium total soluble Pb(II) (TOTSOLPb) concentrations under a variety of practical scenarios. The developed R code file (app.R) is publicly available for download at GitHub (https://github.com/USEPA/TELSS) along with instructions to run the R code locally, allowing the user to explore Pb(II) solubility by selecting desired simulation conditions (e.g., water quality, equilibrium constants, and Pb(II) solids to consider). In addition, the R code serves as a reproducible baseline for alternative model development and future model improvements, allowing users to update, modify, and share the R code to meet their needs. Using the R code, several solubility diagrams were generated to highlight practical relationships related to TOTSOLPb concentrations, including the impact of pH and dissolved inorganic carbon, orthophosphate, sulfate, and chloride concentrations.
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Affiliation(s)
- David G Wahman
- United States Environmental Protection Agency, Office of Research & Development, Cincinnati, Ohio, USA
| | - Matthew D Pinelli
- Oak Ridge Associated Universities (ORAU) Contractor to USEPA, Cincinnati, Ohio, USA
| | - Michael R Schock
- United States Environmental Protection Agency, Office of Research & Development, Cincinnati, Ohio, USA
| | - Darren A Lytle
- United States Environmental Protection Agency, Office of Research & Development, Cincinnati, Ohio, USA
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8
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Li B, Trueman BF, Rahman MS, Gagnon GA. Controlling lead release due to uniform and galvanic corrosion - An evaluation of silicate-based inhibitors. JOURNAL OF HAZARDOUS MATERIALS 2021; 407:124707. [PMID: 33341575 DOI: 10.1016/j.jhazmat.2020.124707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 11/03/2020] [Accepted: 11/26/2020] [Indexed: 06/12/2023]
Abstract
Silicates have been added to drinking water for decades, both to sequester iron/manganese and as a corrosion control treatment for lead. But the mechanisms by which they might act to limit lead release are not well understood. We evaluated the effects of two silicate formulations on lead release due to uniform and galvanic corrosion over a wide range of pH and dissolved inorganic carbon concentrations. We compared these results to better-characterized systems, with added ortho- or polyphosphate and in an inhibitor-free control. Independent of pH, silicates did not consistently mitigate lead release due to either uniform or galvanic corrosion. Furthermore, lead carbonates appeared to determine lead solubility in the presence of sodium silicate. While silicate treatment did promote the formation of a nanometer-thick silicon layer on lead and a decrease in crystallite size at the scale surface, these changes did not inhibit lead release. But unlike polyphosphate-which is known to form soluble complexes with lead and disperse particulate metals-high ratio silicate did not exacerbate lead release. Metasilicate did exacerbate lead release, especially at pH 7 and 5 mg DIC/L; this suggests that silicate formulation may have an important effect on the dispersion of lead-rich particles.
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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 B3H 4R2, Canada.
| | - Benjamin F Trueman
- Centre for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington St., Halifax, Nova Scotia B3H 4R2, Canada
| | - Mohammad Shahedur Rahman
- Centre for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington St., Halifax, Nova Scotia B3H 4R2, Canada; Civil Engineering Department, College of Engineering, Al Imam Mohammad Ibn Saud Isalamic University, Riyadh, Saudi Arabia
| | - Graham A Gagnon
- Centre for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington St., Halifax, Nova Scotia B3H 4R2, Canada
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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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Doré E, Deshommes E, Laroche L, Nour S, Prévost M. Lead and copper release from full and partially replaced harvested lead service lines: Impact of stagnation time prior to sampling and water quality. WATER RESEARCH 2019; 150:380-391. [PMID: 30550868 DOI: 10.1016/j.watres.2018.11.076] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 11/20/2018] [Accepted: 11/27/2018] [Indexed: 06/09/2023]
Abstract
Partial lead service line replacement (PLSLR) results in the addition of a new galvanic connection and can increase lead concentrations at the tap. Focus has been given to minimizing lead release after PLSLR, but little information is available on the impact of lead remedial actions on copper concentrations, especially before passivation occurs. The impact of water quality (decreased chloride-to-sulfate mass ratio from 0.9 to 0.3; addition of orthoP; pH increase to 8.3) on lead and copper concentrations was investigated after stagnation (30 min-336 h) in a pipe rig comparing full lead service line (LSL), and two configurations of partial LSLs (Cu-Pb and Pb-Cu). Results show different trends for lead and copper: maximum lead concentrations were reached in 16 h while copper concentrations continued to increase over 336 h. Lead release rates were also the highest in the first 16 h of stagnation and were strongly impacted by water quality and the configuration of PLSLR (Cu-Pb vs Pb-Cu). Increasing the sampling flow rate from 5 to 15 LPM drastically increased the particulate lead release (78-fold) in Pb-Cu configurations; this effect was however not observed in 100% Pb or Cu-Pb configurations. High velocity flushing prior to 16 h stagnation decreased total Pb release by a factor of 12-fold for Cu-Pb, 1.6-fold for Pb-Cu and 2.0-fold for 100% Pb. Results support the definition of sampling protocols targeted for the detection of lead and copper sources and the proscription of flushing prior to sampling.
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Affiliation(s)
- Evelyne Doré
- NSERC Industrial Chair on Drinking Water, Department of Civil, Mining and Geological Engineering, Polytechnique Montreal, Montréal, QC, H3T 1J4, Canada.
| | - Elise Deshommes
- NSERC Industrial Chair on Drinking Water, Department of Civil, Mining and Geological Engineering, Polytechnique Montreal, Montréal, QC, H3T 1J4, Canada
| | - Laurent Laroche
- Ville de Montréa, Technical Expertise Division, Montreal, QC, H8N 2K2, Canada
| | - Shokoufeh Nour
- NSERC Industrial Chair on Drinking Water, Department of Civil, Mining and Geological Engineering, Polytechnique Montreal, Montréal, QC, H3T 1J4, Canada
| | - Michèle Prévost
- NSERC Industrial Chair on Drinking Water, Department of Civil, Mining and Geological Engineering, Polytechnique Montreal, Montréal, QC, H3T 1J4, Canada
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