1
|
Lian W, Yu G, Ma J, Xiong J, Niu C, Zhang R, Xie H, Weng L. Quantitative Insights into Phosphate-Enhanced Lead Immobilization on Goethite. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:11748-11759. [PMID: 38912726 DOI: 10.1021/acs.est.4c03927] [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: 06/25/2024]
Abstract
Despite extensive study, geochemical modeling often fails to accurately predict lead (Pb) immobilization in environmental samples. This study employs the Charge Distribution MUlti-SIte Complexation (CD-MUSIC) model, X-ray absorption fine structure (XAFS), and density functional theory (DFT) to investigate mechanisms of phosphate (PO4) induced Pb immobilization on metal (hydr)oxides. The results reveal that PO4 mainly enhances bidentate-adsorbed Pb on goethite via electrostatic synergy at low PO4 concentrations. At relatively low pH (below 5.5) and elevated PO4 concentrations, the formation of the monodentate-O-sharing Pb-PO4 ternary structure on goethite becomes important. Precipitation of hydropyromorphite (Pb5(PO4)3OH) occurs at high pH and high concentrations of Pb and PO4, with an optimized log Ksp value of -82.02. The adjustment of log Ksp compared to that in the bulk solution allows for quantification of the overall Pb-PO4 precipitation enhanced by goethite. The CD-MUSIC model parameters for both the bidentate Pb complex and the monodentate-O-sharing Pb-PO4 ternary complex were optimized. The modeling results and parameters are further validated and specified with XAFS analysis and DFT calculations. This study provides quantitative molecular-level insights into the contributions of electrostatic enhancement, ternary complexation, and precipitation to phosphate-induced Pb immobilization on oxides, which will be helpful in resolving controversies regarding Pb distribution in environmental samples.
Collapse
Affiliation(s)
- Wanli Lian
- Key Laboratory for Environmental Factors Control of Agro-Product Quality Safety, Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China
| | - Guanghui Yu
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Jie Ma
- Key Laboratory for Environmental Factors Control of Agro-Product Quality Safety, Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China
| | - Juan Xiong
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs of the People's Republic of China, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Cuiyun Niu
- Key Laboratory for Environmental Factors Control of Agro-Product Quality Safety, Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China
| | - Ran Zhang
- Key Laboratory for Environmental Factors Control of Agro-Product Quality Safety, Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China
| | - Haijiao Xie
- Hangzhou Yanqu Information Technology Co., Ltd, Hangzhou 310003, China
| | - Liping Weng
- Key Laboratory for Environmental Factors Control of Agro-Product Quality Safety, Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China
- Department of Soil Quality, Wageningen University, P.O. Box 47, 6700AA Wageningen, The Netherlands
| |
Collapse
|
2
|
Hu Y, Zhang S, Zhou Z, Cao Z. Heterogeneous Coprecipitation of Nanocrystals with Metals on Substrates. Acc Chem Res 2024; 57:1254-1263. [PMID: 38488208 DOI: 10.1021/acs.accounts.3c00807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
ConspectusThe heterogeneous coprecipitation of nanocrystals with metals on substrates plays a significant role in both natural and engineered systems. Due to the small dimensions and thereby the large specific surface area, nanocrystal coprecipitation with metals, which is ubiquitous in natural settings, exerts drastic effects on the biogeochemical cycling of metals on the earth's crust. Meanwhile, the controlled synthesis of nanocrystals with metal doping to achieve tunable size/composition enables their broad applications as adsorbents and catalysts in many engineered settings. Despite their importance, complex interactions among aqueous ions/polymers, nanocrystals, substrates, and metals are far from being well-understood, leaving the controlling mechanisms for nanocrystal formation with metals on substrates uncovered.In this Account, we discuss our systematic investigation over the past 10 years of the heterogeneous formation of representative nanocrystals with metals on typical substrates. We chose Fe(OH)3 and BaSO4 as representative nanocrystals. Mechanisms for varied metal coprecipitation were also investigated for both types of nanocrystals (i.e., Fe, Al, Cr, Cu, and Pb)(OH)3 and (Ba, Sr)(SO4, SeO4, and SeO3)). Bare SiO2 and Al2O3, as well as those coated with varied organics, were selected as geologically or synthetically representative substrates. Through the integration of state-of-the-art nanoscale interfacial characterization techniques with theoretical calculations, the complex interactions during nanocrystal formation at interfaces were probed and the controlling mechanisms were identified.For BaSO4 and Fe(OH)3 formation on substrates, the local supersaturation levels near substrates were controlled by Ba2+ adsorption and the electrostatic attraction of Fe(OH)3 monomer/polymer to substrates, respectively. Meanwhile, substrate hydrophobicity controlled the interfacial energy for the nucleation of both nanocrystals on (in)organic substrates. Metal ions' (i.e., Cr/Al/Cu/Pb) hydrolysis constants and substrates' dielectric constants controlled metal ion adsorption onto substrates, which altered the surface charges of substrates, thus controlling heterogeneous Fe(OH)3 nanocrystal formation on substrates by electrostatic interactions. The sizes and compositions of heterogeneous (Fe, Cr)(OH)3 and (Ba, Sr)(SO4, SeO4, SeO3) formed on substrates were found to be distinct from those of homogeneous precipitates formed in solution. The substrate (de)protonation could alter the local solution's pH and the substrates' surface charge; substrates could also adsorb cations, affecting local Fe/Cr/Ba/Sr ion concentrations at solid-water interfaces, thus controlling the amount/size/composition of nanocrystals by tuning their nucleation/growth/deposition on substrates. From slightly supersaturated solution, homogeneous coprecipitates of microsized (Ba, Sr)(SO4, SeO4, SeO3) formed through growth, with little Sr/Se(VI) incorporation due to higher solubilities of SrSO4 and BaSeO4 over BaSO4. While cation enrichment near substrates made the local solution highly supersaturated, nanosized coprecipitates formed on substrates through nucleation, with more Sr/Se(VI) incorporation due to lower interfacial energies of SrSO4 and BaSeO4 over BaSO4. The new insights gained advanced our understanding of the biogeochemical cycling of varied elements at solid-water interfaces and of the controlled synthesis of functional nanocrystals.
Collapse
Affiliation(s)
- Yandi Hu
- School of Environmental Science and Engineering, Peking University, Beijing 100871, China
- State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, Beijing 100871, China
| | - Suona Zhang
- School of Environmental Science and Engineering, Peking University, Beijing 100871, China
- State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, Beijing 100871, China
| | - Zehao Zhou
- School of Environmental Science and Engineering, Peking University, Beijing 100871, China
- State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, Beijing 100871, China
| | - Zhiqian Cao
- School of Environmental Science and Engineering, Peking University, Beijing 100871, China
- State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, Beijing 100871, China
| |
Collapse
|
3
|
Tully J, Schock M, Shilling S, Bosscher V, Lytle D, Harmon S, Bennett-Stamper C. An evaluation of properly operated NSF/ANSI-53 Pb certified drinking water filters in Benton Harbor, MI. JOURNAL OF WATER AND HEALTH 2024; 22:296-308. [PMID: 38421624 PMCID: PMC11182191 DOI: 10.2166/wh.2024.231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
Communities across the United States and particularly in the Midwest continue to grapple with the complications associated with aging infrastructure. This includes the presence of lead (Pb)-bearing plumbing components such as lead service lines, downstream galvanized iron pipes, and Pb/tin solder. The community of Benton Harbor, MI, experienced six Pb action level exceedances between 2018 and 2021, leading to increasing community concern and a request from the state of Michigan for the US Environmental Protection Agency involvement. Between 9 November and 17 December 2021, US EPA Region 5 and Office of Research and Development, along with the state of Michigan, conducted a water filter efficacy and Pb-nanoparticulate (<100 nm) study to evaluate the performance of NSF/ANSI-53 Pb-certified drinking water filters and the presence of nanoparticulate. In this study, a total of 199 properly installed and operated drinking water filters (combination of faucet mounted and pitcher) were tested in their residential locations. One hundred percent of the water filters were found to perform to the standard to which they were certified, with filtered drinking water Pb concentrations below 5 ppb (maximum observed was 2.5 ppb). In addition, Pb particulate was identified; however, discrete Pb-containing nanoparticles were not widely found or identified.
Collapse
Affiliation(s)
- Jennifer Tully
- U.S. Environmental Protection Agency, Center for Environmental Solutions and Emergency Response, Water Infrastructure Division, 26 W. Martin Luther King Dr, Cincinnati, OH 45268, USA E-mail:
| | - Michael Schock
- U.S. Environmental Protection Agency, Center for Environmental Solutions and Emergency Response, Water Infrastructure Division, 26 W. Martin Luther King Dr, Cincinnati, OH 45268, USA
| | - Scott Shilling
- Oak Ridge Associated Universities, U.S. Environmental Protection Agency, Center for Environmental Solutions and Emergency Response, Water Infrastructure Division, 26 W. Martin Luther King Dr, Cincinnati, OH 45268, USA
| | - Valerie Bosscher
- U.S. Environmental Protection Agency, Region 5, Water Division, Ground Water and Drinking Water Branch, Chicago, IL 60605, USA
| | - Darren Lytle
- U.S. Environmental Protection Agency, Center for Environmental Solutions and Emergency Response, Water Infrastructure Division, 26 W. Martin Luther King Dr, Cincinnati, OH 45268, USA
| | - Stephen Harmon
- U.S. Environmental Protection Agency, Center for Environmental Solutions and Emergency Response, Water Infrastructure Division, 26 W. Martin Luther King Dr, Cincinnati, OH 45268, USA
| | - Christina Bennett-Stamper
- U.S. Environmental Protection Agency, Center for Environmental Solutions and Emergency Response, Water Infrastructure Division, 26 W. Martin Luther King Dr, Cincinnati, OH 45268, USA
| |
Collapse
|
4
|
Wang Z. Phosphorus-modified bone chars with developed porosity for efficient removal of Pb(II), Cu(II), and Cd(II). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:123796-123807. [PMID: 37991622 DOI: 10.1007/s11356-023-31080-9] [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: 09/20/2023] [Accepted: 11/13/2023] [Indexed: 11/23/2023]
Abstract
Guided by the concept of treating the wastes with wastes, the efficient use of bone residuals as separation materials is worthy of study. Since bone chars (BCs) are composed of hydroxyapatite and carbon matrix, it is desired to extend the carbon component with improved pore structure and abundant modified groups further, which is favorable to capture metal ions. In this work, phosphorus-modified BCs (PBCs) were fabricated by pretreating bone residuals with phytic acid, achieving improved surface areas (208.7-517.6 m2/g, 37.9-8.2-fold of enhancement) and abundant surface phosphorus contents (5.63-7.54 at.%, 2.8-5.8-fold of enhancement) than BCs. PBCs could adsorb heavy metals with fast kinetics (10.0 h) and excellent maximum capacities (463.9, 156.5, and 80.9 mg/g for Pb(II), Cu(II), and Cd(II)). Spectroscopic results demonstrated that the formation of precipitation was crucial for the enrichment of Pb(II). Moreover, the coordination with functional groups (O-/reductive N-species), the cation exchange with inorganic Ca2+, the electrostatic attraction with deprotonated O-, and the cation-π coordination should also be considered for the sorption. Our study facilitated the application of activated bone wastes as a promising candidate to remediate aquatic heavy metals.
Collapse
Affiliation(s)
- Zihao Wang
- School of Chemical Engineering, The University of Queensland, Brisbane, QLD, 4072, Australia.
| |
Collapse
|
5
|
Du X, Rashid SA, Abdullah LC, Rahman NA. Fabrication of electrospun cellulose/chitosan/ball-milled bone char membranes for efficient and selective sorption of Pb(II) from aqueous solutions. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:110417-110430. [PMID: 37783997 DOI: 10.1007/s11356-023-30213-4] [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: 07/27/2023] [Accepted: 09/27/2023] [Indexed: 10/04/2023]
Abstract
Separation materials have received increasing attention given their broad applications in the management of environmental pollution. It is desired to balance the contradiction between high separation efficiency and selectivity of separation materials. The integration of ball-milled bone chars with electrospun membranes might achieve this balance. In this study, electrospun cellulose/chitosan/ball-milled bone char (CL/CS/MB) membranes were by well-dispersing ball-milled bone chars with nanoscale size (98.9-167.5 nm) and developed porosity (40.2-373.1 m2/g) in the electrospinning solvent. The synergistic integration of distributed MBs (5.4-31.5 wt.% of loading hydroxyapatite on the membrane matrix) allowed the efficient sorption of Pb(II) with fast kinetics (20.0 min), excellent capacity (219.9 mg/g at pH 5.0, T 298 K), and favorable selectivity coefficients (2.76-6.79). The formation of minerals was dominant for the selective sorption of Pb(II) by combining the spectral analysis and quantitative determination. The surface complexation with O-/reductive N-species, the cation exchange with inorganic Ca2+, the electrostatic attraction with deprotonated O-, and the cation-π coordination with the aromatic carbon via the π-electrons should be not ignored for the capture of Pb(II). This work demonstrated the feasibility of electrospun CL/CS/MB membranes as a promising candidate for the remediation of aquatic pollutants.
Collapse
Affiliation(s)
- Xuan Du
- Nanomaterials Processing and Technology Laboratory, Institute of Nanoscience and Nanotechnology, Universiti Putra Malaysia, 43400, Serdang, Malaysia
| | - Suraya Abdul Rashid
- Nanomaterials Processing and Technology Laboratory, Institute of Nanoscience and Nanotechnology, Universiti Putra Malaysia, 43400, Serdang, Malaysia.
| | - Luqman Chuah Abdullah
- Department of Chemical and Environmental Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400, Serdang, Malaysia
| | - Norizah Abdul Rahman
- Nanomaterials Processing and Technology Laboratory, Institute of Nanoscience and Nanotechnology, Universiti Putra Malaysia, 43400, Serdang, Malaysia
| |
Collapse
|
6
|
Zhuang Y, Gao Y, Shi B. Iron particles lower than 10 μm in drinking water dominate particle catalysis effect on disinfection byproduct formation. WATER RESEARCH 2023; 245:120634. [PMID: 37748342 DOI: 10.1016/j.watres.2023.120634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 09/09/2023] [Accepted: 09/13/2023] [Indexed: 09/27/2023]
Abstract
Iron particles could catalyze disinfection by-product (DBP) formation in drinking water distribution systems (DWDS), but the catalytic effects of iron particles considering size effects have not been focused. Here, we first found that fine particles (lower than 10 μm) dominated the particle catalysis effect of the iron particles on the formation of DBPs containing multiple Cl atoms (DBP-3Cl), especially those with aromatic structure and containing multiple N atoms (DBP-3N). The loose deposit particles were filtered through 50 μm (F50), 10 μm (F10) and 1 μm (F10) membranes, and their turbidity values were 231.6, 53.4 and 1.1 NTU, respectively. In mass ratio, F50, F10 and F1 accounted for 84 %, 15 % and 1 % of unfiltered samples. Notably, the lower mass F10 generated more DBP-3Cl and DBP-3N than F50. Metal crystals and natural organic matters showed little difference among different sizes. The high catalytic activity of particles in F10 due to size effect was proved to be the essential mechanism. F1 contained few particles to affect DBP formation. In toxicity evaluation, the toxicity of F10 was even higher than F50. Therefore, fine particles with sizes lower than 10 μm may play a dominate role in the catalytic effect on DBP transformation in DWDS.
Collapse
Affiliation(s)
- Yuan Zhuang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yujia Gao
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Baoyou Shi
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| |
Collapse
|
7
|
Zhou T, Lu L, Tao S, Ma Y. Removal of Pb(II) and phosphorus in water by γ-Al 2O 3/biochar. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-27416-0. [PMID: 37166729 DOI: 10.1007/s11356-023-27416-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 04/30/2023] [Indexed: 05/12/2023]
Abstract
In this work, we synthesized activated alumina biochar composites (γ-Al2O3/BC) by sol-gel method, which improved the problem that the surface charge of γ-Al2O3 was not conducive to the removal of heavy metal cation in a neutral solution, and then explored the feasibility of removing Pb(II) by γ-Al2O3/BC as well as reusing Pb-laden waste sludge to remove phosphorus (P) and its micro-adsorption mechanisms. The results show that the maximum adsorption capacity of γ-Al2O3/BC for Pb(II) is 182.48 mg/g, and the removing capacity of recycled Pb-laden slag for P also reaches 87.13 mg/g. It was found that the presence of Pb in the slag makes P removal more effective. In addition, in the process of P removal, the Pb in the slag will not be released, which will not cause secondary pollution to the water. The micro-adsorption mechanism of Pb(II) and P on the composites was investigated by XPS, XRD, and FTIR. It demonstrates that special functional groups such as hydroxy-aluminum, hydroxyl, and carboxyl groups can remove Pb(II) through strong surface complexation and electrostatic attraction. Furthermore, the removal mechanism of P from Pb-laden sludge includes chemisorption and complexation, and the precipitation of P and Pb on the adsorbent surface is the main reason for the removal of P. Therefore, it is feasible to further effectively remove P by using the waste biochar containing Pb. The idea of this paper provides a potential method for the reuse of waste adsorbent.
Collapse
Affiliation(s)
- Tao Zhou
- College of Chemical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816, People's Republic of China
| | - Linghong Lu
- College of Chemical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816, People's Republic of China.
| | - Suwan Tao
- College of Chemical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816, People's Republic of China
| | - Yi Ma
- College of Chemical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816, People's Republic of China
| |
Collapse
|
8
|
Liu J, Zhao J, Louie SM, Gao X, Zhang P, Liang D, Hu Y. Comparative study on effects of pH, electrolytes, and humic acid on the stability of acetic and polyacrylic acid coated magnetite nanoparticles. CHEMOSPHERE 2023; 319:137992. [PMID: 36720411 DOI: 10.1016/j.chemosphere.2023.137992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 01/17/2023] [Accepted: 01/27/2023] [Indexed: 06/18/2023]
Abstract
The poor colloidal stability of magnetite nanoparticles (MNPs) limits their mobility and application, so various organic coatings (OCs) were applied to MNPs. Here, a comparative study on the colloidal stability of MNPs coated with acetic (HAc) and polyacrylic acids (PAA) was conducted under varied pH (5.0-9.0) in the presence of different concentrations of cations and anions, as well as humic acid (HA). Comparing the effects of various cations and anions, the stability of both HAc/PAA-MNPs followed the order: Na+ > Ca2+and PO43- > SO42- > Cl-, which could be explained by their adsorption behaviors onto HAc/PAA-MNPs and the resulting surface charge changes. Under all conditions even with more anion adsorption onto HAc-MNPs (0.14-22.56 mg/g) than onto PAA-MNPs (0.04-18.34 mg/g), PAA-MNPs were more negatively charged than HAc-MNPs, as PAA has a lower pHIEP (2.6 ± 0.1) than that of HAc (3.7 ± 0.1). Neither the HAc nor PAA coatings were displaced by phosphate even at considerably high phosphate concentration. Compared with HAc-MNPs, the stability of PAA-MNPs was greatly improved under all studied conditions, which could be due to both stronger electrostatic and additional steric repulsion forces among PAA-MNPs. Besides, under all conditions, Derjaguin-Landau-Verwey-Overbeek (DLVO) explained well the aggregation kinetic of HAc-MNPs; while extended DLVO (EDLVO) successfully predict that of PAA-MNPs, indicating steric forces among PAA-MNPs. The aggregation of HAc/PAA-MNPs was all inhibited in varied electrolyte solutions by HA (2 mg C/L) addition. This study suggested that carboxyl coatings with higher molecular weights and pKa values could stabilize MNPs better due to stronger electrostatic and additional steric repulsion. However, in the presence of HA, these two forces were mainly controlled by adsorbed HA instead of the organic pre-coatings on MNPs.
Collapse
Affiliation(s)
- Juanjuan Liu
- State Key Laboratory of Biogeology & Environmental Geology and School of Environmental Studies, China University of Geosciences, Wuhan, Hubei, 430074, PR China; College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi, 712100, China; The Key Laboratory of Water and Sediment Sciences (Ministry of Education), State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Juntao Zhao
- Department of Civil & Environmental Engineering, University of Houston, Houston, TX, 77004, United States; Benchmark Lab & Services, Houston, TX, 77092, United States
| | - Stacey M Louie
- Department of Civil & Environmental Engineering, University of Houston, Houston, TX, 77004, United States
| | - Xubo Gao
- State Key Laboratory of Biogeology & Environmental Geology and School of Environmental Studies, China University of Geosciences, Wuhan, Hubei, 430074, PR China
| | - Ping Zhang
- Faculty of Science and Technology, University of Macau, Macau, 999078, China
| | - Dongli Liang
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi, 712100, China.
| | - Yandi Hu
- The Key Laboratory of Water and Sediment Sciences (Ministry of Education), State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China.
| |
Collapse
|
9
|
Zhao J, Mathew RA, Yang DS, Vekilov PG, Hu Y, Louie SM. Natural organic matter flocculation behavior controls lead phosphate particle aggregation by mono- and divalent cations. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 866:161346. [PMID: 36603637 DOI: 10.1016/j.scitotenv.2022.161346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 11/18/2022] [Accepted: 12/29/2022] [Indexed: 06/17/2023]
Abstract
Phosphate addition is commonly applied to remediate lead contaminated sites via the formation of lead phosphate particles with low solubility. However, the effects of natural organic matter (NOM) with different properties, as well as the contributions of specific interactions (particle-particle, particle-NOM, and NOM-NOM) in enhanced stabilization or flocculation of the particles, are not currently well understood. This study investigates the influence of two aquatic NOM and two soil or coal humic acid (HA) extracts on the aggregation behavior of lead phosphate particles and explores the controlling mechanisms. All types of NOM induced disaggregation and steric stabilization of the particles in the presence of Na+ (100 mM) or low (1 mM) Ca2+ concentrations, as well as at low NOM concentrations (1 mgC/L). However, for the soil and coal HA, a threshold at NOM concentrations of 10 mgC/L and high (3 mM) Ca2+ concentrations was observed where bridging flocculation (rather than steric stabilization) occurred. In situ attenuated total reflectance - Fourier transform infrared characterization confirmed adsorption of the soil and coal humic acid extracts (10 mgC/L) onto the surface of the lead phosphate particles in 3 mM Ca2+, whereas dynamic and static light scattering demonstrated extensive HA flocculation that dominated the overall scattered light intensities. These results imply that the accelerated aggregation was induced by a combination of HA adsorption and bridging flocculation by Ca2+. Overall, this research demonstrates that the type of NOM is critical to predict the colloidal stability of lead phosphate particles. Aquatic NOM stabilized the particles under all conditions evaluated, but soil or coal HA with higher molecular weight and aromaticity showed highly variable stabilization or flocculation behavior depending on the HA and Ca2+ concentrations available to adsorb to the particles and participate in bridging. These results provide new mechanistic insights on particle stabilization or destabilization by NOM.
Collapse
Affiliation(s)
- Juntao Zhao
- Department of Civil & Environmental Engineering, University of Houston, Houston, TX 77004, USA
| | - Riya A Mathew
- Department of Civil & Environmental Engineering, University of Houston, Houston, TX 77004, USA
| | - David S Yang
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77004, USA
| | - Peter G Vekilov
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77004, USA
| | - Yandi Hu
- Department of Civil & Environmental Engineering, University of Houston, Houston, TX 77004, USA; College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, Beijing 100871, China
| | - Stacey M Louie
- Department of Civil & Environmental Engineering, University of Houston, Houston, TX 77004, USA.
| |
Collapse
|
10
|
Anderson LE, DeMont I, Dunnington DD, Bjorndahl P, Redden DJ, Brophy MJ, Gagnon GA. A review of long-term change in surface water natural organic matter concentration in the northern hemisphere and the implications for drinking water treatment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 858:159699. [PMID: 36306839 DOI: 10.1016/j.scitotenv.2022.159699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 10/20/2022] [Accepted: 10/20/2022] [Indexed: 06/16/2023]
Abstract
Reduced atmospheric acid deposition has given rise to recovery from acidification - defined as increasing pH, acid neutralization capacity (ANC), or alkalinity in surface waters. Strong evidence of recovery has been reported across North America and Europe, driving chemical responses. The primary chemical responses identified in this review were increasing concentration and changing character of natural organic matter (NOM) towards predominantly hydrophobic nature. The concentration of NOM also influenced trace metal cycling as many browning surface waters also reported increases in Fe and Al. Further, climate change and other factors (e.g., changing land use) act in concert with reductions in atmospheric deposition to contribute to widespread browning and will have a more pronounced effect as deposition stabilizes. The observed water quality trends have presented challenges for drinking water treatment (e.g., increased chemical dosing, poor filter operations, formation of disinfection by-products) and many facilities may be under designed as a result. This comprehensive review has identified key research areas to be addressed, including 1) a need for comprehensive monitoring programs (e.g., larger timescales; consistency in measurements) to assess climate change impacts on recovery responses and NOM dynamics, and 2) a better understanding of drinking water treatment vulnerabilities and the transition towards robust treatment technologies and solutions that can adapt to climate change and other drivers of changing water quality.
Collapse
Affiliation(s)
- Lindsay E Anderson
- Centre for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington St. Halifax, Nova Scotia, Canada.
| | - Isobel DeMont
- Centre for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington St. Halifax, Nova Scotia, Canada
| | - Dewey D Dunnington
- Centre for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington St. Halifax, Nova Scotia, Canada
| | - Paul Bjorndahl
- Department of Mathematics & Statistics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Dave J Redden
- Centre for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington St. Halifax, Nova Scotia, Canada
| | | | - Graham A Gagnon
- Centre for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington St. Halifax, Nova Scotia, Canada
| |
Collapse
|
11
|
Phosphorus modified graphitic carbon nitride activated by guanidine phosphate enables fast, efficient and selective immobilization of aquatic lead. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
12
|
Lee J, Ko Y, Kim S, Hur HG. Highly effective biosorption capacity of Cladosporium sp. strain F1 to lead phosphate mineral and perovskite solar cell PbI 2. JOURNAL OF HAZARDOUS MATERIALS 2023; 442:130106. [PMID: 36209612 DOI: 10.1016/j.jhazmat.2022.130106] [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: 07/06/2022] [Revised: 09/27/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
Fungus Cladosporium sp. strain F1 showed highly effective biosorption capacity to lead phosphate mineral and perovskite solar cells lead iodide compared to other fungi Aspergillus niger VKMF-1119 and Mucor ramannianus R-56. Scanning electron microscopy and transmission electron microscopy analyses shows that Cladosporium sp. strain F1, which previously showed high biosorption capacity to uranium phosphate nanorods and nanoplates, can accumulate lead phosphate mineral and lead iodide on the fungal hyphae surface in large amounts under a wide range of pH conditions, while A. niger VKMF-1119 and M. ramannianus R-56 adsorbed small amounts of minerals. After biosorption of lead iodide minerals on Cladosporium sp. strain F1, aqueous dimethyl sulfoxide (50%) at pH 2 (70 °C) released the mineral more than 99%. Based on the fungal surface analyses, hydrophobic properties on the surfaces of Cladosporium sp. strain F1 could affect the higher biosorption capacity of strain F1 to lead phosphate mineral and lead iodide as compared to other tested fungi. Cladosporium sp. strain F1 may be the novel biosorbents to remediate the phosphate rich environment and to recover lead from perovskite solar cells lead iodide.
Collapse
Affiliation(s)
- Jisu Lee
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - Yongseok Ko
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - Sungho Kim
- GIST Central Research Facilities, Gwanju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - Hor-Gil Hur
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea.
| |
Collapse
|
13
|
Gao Y, Trueman BF, Gagnon GA. Early phase effects of silicate and orthophosphate on lead (Pb) corrosion scale development and Pb release. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 321:115947. [PMID: 35977436 DOI: 10.1016/j.jenvman.2022.115947] [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: 04/30/2022] [Revised: 07/30/2022] [Accepted: 08/02/2022] [Indexed: 06/15/2023]
Abstract
Orthophosphate is widely used to control lead (Pb) release in drinking water distribution systems, but phosphorus addition is not sustainable. Alternative corrosion control treatments are needed, and sodium silicate is one possibility. Here, pre-corroded Pb coupons-with and without free chlorine-were used to examine early-phase corrosion scale development after silicate addition, with orthophosphate as a reference corrosion inhibitor. Scale development was evaluated in terms of total Pb release, phase transformation, electrochemical impedance, morphological changes, Pb dissolution kinetics, and short-term Pb-Cu galvanic corrosion. Elevated Pb release occurred for approximately one month after silicate addition, and total Pb release peaked at 1968.1 μg/L and 1176.9 μg/L from systems with and without free chlorine, respectively. In contrast, orthophosphate-treated coupons exhibited fewer, less pronounced spikes in Pb release. By day 354, the median total Pb release from orthophosphate-treated coupons with and without free chlorine had decreased to 3.7 and 5.0 μg/L, respectively, while the median total Pb release from corresponding silicate-treated coupons was much higher, at 44.9 μg/L and 34.3 μg/L. Calcium lead apatite (Ca0.56Pb3.77(PO4)3OH0.67) was identified in orthophosphate-treated scales, with hydroxylpyromorphite (Pb5(PO4)3OH) present in the absence of free chlorine. Plattnerite occurred on coupons in all chlorinated systems. Pb silicate compounds were not detected, but Ca2SiO4 and Na2Ca2(SiO3)3 were identified by X-ray powder diffraction. The charge transfer: film resistance ratio characterizing the orthophosphate-treated coupons decreased slowly while that of the silicate-treated coupons increased after silicate was added. These variations suggest orthophosphate provided better corrosion control than silicate did. Silicate treatment generally caused degradation of the top Pb scale layer, resulting in elevated Pb release, while orthophosphate encouraged the growth of more structured, generally thicker, corrosion scales that were effective in limiting Pb release.
Collapse
Affiliation(s)
- Yaohuan Gao
- School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, 28 Xianning West Road, Xi'an, Shaanxi, 710049, PR China; Department of Civil and Resource Engineering, Dalhousie University, 1360 Barrington Street, Halifax, Nova Scotia, B3H 4R2, Canada.
| | - Benjamin F Trueman
- Department of Civil and Resource Engineering, Dalhousie University, 1360 Barrington Street, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Graham A Gagnon
- Department of Civil and Resource Engineering, Dalhousie University, 1360 Barrington Street, Halifax, Nova Scotia, B3H 4R2, Canada
| |
Collapse
|
14
|
Impacts of orthophosphate-polyphosphate blends on the dissolution and transformation of lead (II) carbonate. Sci Rep 2022; 12:17885. [PMID: 36284172 PMCID: PMC9596708 DOI: 10.1038/s41598-022-22683-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 10/18/2022] [Indexed: 01/20/2023] Open
Abstract
Orthophosphate-polyphosphate blends are commonly used to control lead release into drinking water, but little is known about how they interact with lead corrosion scale. Conventional corrosion control practice assumes that orthophosphate controls lead release by forming insoluble Pb-phosphate minerals, but this does not always occur, and under certain conditions, phosphate blends may increase lead release. Here, we used continuously-stirred tank reactors to compare orthophosphate-polyphosphate blends with orthophosphate on the basis of lead (II) carbonate dissolution and transformation at environmentally relevant phosphate concentrations. Three model polyphosphates-tripoly-, trimeta- and hexametaphosphate-were used. Hexametaphosphate was the strongest complexing agent (1.60-2.10 molPb/molPolyphosphate), followed by tripolyphosphate and trimetaphosphate (1.00 and 0.07 molPb/molPolyphosphate, respectively. At equivalent orthophosphate and polyphosphate concentrations (as P), orthophosphate-trimetaphosphate had minimal impact on lead release, while orthophosphate-tripolyphosphate increased dissolved lead. Orthophosphate-hexametaphosphate also increased dissolved lead, but only over a 24-h stagnation. Both orthophosphate-tripolyphosphate and orthophosphate-hexametaphosphate increased colloidal lead after 24-h. Increasing the concentrations of hexameta- and tripoly-phosphate increased dissolved lead release, while all three polyphosphates inhibited the formation of hydroxypyromorphite and reduced the phosphorus content of the resulting lead solids. We attributed the impacts of orthophosphate-polyphosphates to a combination of complexation, adsorption, colloidal dispersion, polyphosphate hydrolysis, and lead mineral precipitation.
Collapse
|
15
|
Su Z, Liu T, Men Y, Li S, Graham N, Yu W. Understanding point-of-use tap water quality: From instrument measurement to intelligent analysis using sample filtration. WATER RESEARCH 2022; 225:119205. [PMID: 36215843 DOI: 10.1016/j.watres.2022.119205] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 09/19/2022] [Accepted: 10/03/2022] [Indexed: 06/16/2023]
Abstract
In most cases, point-of-use tap water quality is not routinely monitored due to widely-dispersed sampling sites and the costly tests. Although previous studies have revealed the variation of drinking water quality during distribution in municipal networks, the influence of aging pipes in buildings on quality is still unknown and this makes it difficult for water utilities to conduct regular maintenance. Herein, we have undertaken a survey of tap water samples across 8 districts in Beijing (China) to evaluate the potential effects of pipe age on point-of-use water quality, including turbidity, organic matter characteristics, and bacterial community. By grouping the collected samples according to the pipe age and source water respectively, the results suggested that bacterial diversity is significantly influenced by the pipe age. However, bacterial community structure is clearly influenced by the source water. Similarly, aging pipes in buildings are also responsible for the deterioration of the final water quality, and their effects have been closely linked to selected water quality parameters by evaluating the relevant factors. Moreover, the interrelationships between physico-chemical parameters and bacteria abundance were identified. For example, pH, Ca2+, Mg2+, Na+ and K+ showed a positive relationship with Bacillus abundance. In addition, an intelligent analysis method for understanding pipe age, organic matter concentration, and hardness (i.e., Ca2+ and Mg2+ concentration), based on image analysis of filtered membranes has been developed. The accuracy of prediction was encouraging, but can be improved with the collection of more data from tap water samples. We expect that this method can be exploited by the public to monitor their tap water and provide a feasible and cost-effective approach for water suppliers to locate aging/deteriorating pipes which need to be replaced or maintained.
Collapse
Affiliation(s)
- Zhaoyang Su
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Ting Liu
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Yujie Men
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, United States
| | - Shuo Li
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Nigel Graham
- Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Wenzheng Yu
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| |
Collapse
|
16
|
Olorunyomi JF, White JF, Gengenbach TR, Caruso RA, Doherty CM. Fabrication of a Reusable Carbon Dot/Gold Nanoparticle/Metal-Organic Framework Film for Fluorescence Detection of Lead Ions in Water. ACS APPLIED MATERIALS & INTERFACES 2022; 14:35755-35768. [PMID: 35905302 DOI: 10.1021/acsami.2c09122] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Solid-state sensing platforms are desirable for the development of reusable sensors to promote public health measures such as testing for drinking water contamination. A bioinspired metal-organic framework (MOF)-based material has been developed by imitating metal-protein interactions in biological systems to attain high sensitivity and selectivity to Pb2+ through fluorescence sensing. A zirconium terephthalate-type framework (also known as NH2-UiO-66) was modified with both gold nanoparticles and thiol-functionalized carbon dots to give HS-C/Au(x)/UiO-66 composites with different Au content (x) and were subsequently adapted into films that show extraordinary sensitivity to Pb2+. The HS-C/Au(1.4)/UiO-66 film that consists of 1.4 wt % Au shows a quenching response with the limit of detection of 80 parts per trillion and sustained performance for five cycles. Moreover, the fluorescence response of the HS-C/Au(x)/UiO-66 film to Pb2+ can be reversed from emission quenching to enrichment of fluorescence by increasing the Au content. The performance of the HS-C/Au(x)/UiO-66 film as a solid-state sensor demonstrates its potential for application in reusable sensing devices to ensure public safety from Pb2+ contamination in drinking water.
Collapse
Affiliation(s)
- Joseph F Olorunyomi
- Applied Chemistry and Environmental Science, School of Science, RMIT University, Melbourne, Victoria 3000, Australia
- CSIRO Manufacturing Clayton, Clayton, Victoria 3168, Australia
| | - Jacinta F White
- CSIRO Manufacturing Clayton, Clayton, Victoria 3168, Australia
| | | | - Rachel A Caruso
- Applied Chemistry and Environmental Science, School of Science, RMIT University, Melbourne, Victoria 3000, Australia
| | - Cara M Doherty
- CSIRO Manufacturing Clayton, Clayton, Victoria 3168, Australia
| |
Collapse
|
17
|
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).
Collapse
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
| |
Collapse
|
18
|
Zhao J, Mowla M, Pan Z, Bao D, Giammar DE, Hu Y, Louie SM. Lead phosphate deposition in porous media and implications for lead remediation. WATER RESEARCH 2022; 214:118200. [PMID: 35228037 DOI: 10.1016/j.watres.2022.118200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 02/13/2022] [Accepted: 02/14/2022] [Indexed: 06/14/2023]
Abstract
Phosphate addition is commonly applied as an effective method to remediate lead contaminated sites via formation of low solubility lead phosphate solids. However, subsequent transport of the lead phosphate particles may impact the effectiveness of this remediation strategy. Hence, this study investigates the mechanisms involved in the aggregation of lead phosphate particles and their deposition in sand columns as a function of typical water chemistry parameters. Clean bed filtration theory was evaluated to predict the particle deposition behavior, using Derjaguin-Landau-Verwey-Overbeek (DLVO) theory to estimate particle-substrate interactions. The observed particle deposition was not predictable from the primary energy barrier in clean bed filtration models, even in simple monovalent background electrolyte (NaNO3), because weak deposition in a secondary energy minimum prevailed even at low ionic strength, and ripening occurred at ionic strengths of 12.5 mM or higher. For aged (aggregated) suspensions, straining also occurred at 12.5 mM or higher. Aggregation and deposition were further enhanced at low total P/Pb ratios (i.e., P/Pb = 1) and in the presence of divalent cations, such as Ca2+ (≥ 0.2 mM), which resulted in less negative particle surface potentials and weaker electrostatic repulsion forces. However, the presence of 5 mg C/L of humic acid induced strong steric or electrosteric repulsion, which hindered particle aggregation and deposition even in the presence of Ca2+. This study demonstrates the importance of myriad mechanisms in lead phosphate deposition and provides useful information for controlling water chemistry in phosphate applications for lead remediation.
Collapse
Affiliation(s)
- Juntao Zhao
- Department of Civil & Environmental Engineering, University of Houston, Houston, TX 77004, United States
| | - Marfua Mowla
- Department of Civil & Environmental Engineering, University of Houston, Houston, TX 77004, United States
| | - Zezhen Pan
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Daniel Bao
- Department of Civil & Environmental Engineering, University of Houston, Houston, TX 77004, United States
| | - Daniel E Giammar
- Department of Energy, Environmental and Chemical Engineering, Washington University, St. Louis, MO 63130, United States
| | - Yandi Hu
- Department of Civil & Environmental Engineering, University of Houston, Houston, TX 77004, United States; College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, Beijing 100871, China.
| | - Stacey M Louie
- Department of Civil & Environmental Engineering, University of Houston, Houston, TX 77004, United States.
| |
Collapse
|
19
|
He N, Hu L, He Z, Li M, Huang Y. Mineralization of lead by Phanerochaete chrysosporium microcapsules loaded with hydroxyapatite. JOURNAL OF HAZARDOUS MATERIALS 2022; 422:126902. [PMID: 34418828 DOI: 10.1016/j.jhazmat.2021.126902] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/03/2021] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
In this study, microcapsules assembled with Phanerochaete chrysosporium (P. chrysosporium, PC) and hydroxyapatite (HAP) were successfully prepared and applied for Pb(II) immobilization in aqueous solution. The effect of different conditions on Pb(II) removal was investigated, such as pH, temperature, dosages of microcapsules and HAP, and initial concentrations of Pb(II). The removal efficiency of Pb(II) was in order of HAP+PC > HAP > PC > CK (control check) at the Pb(II) initial concentration of 100 mg L-1, which were 87.7%, 82.82%, 63.67% and 2.06%, respectively. Under HAP+PC treatment, P. chrysosporium secreted plentiful organic acids like formic, oxalic and citric acids, when the addition dose of HAP increased from 5 g L-1 to 15 g L-1, the production of formic acid increased remarkably from 32.37 g L-1 to 66.02 g L-1. After reaction, P. chrysosporium kept a good biological activity evidenced by the live/dead stain test. The characterization results indicated that the insoluble apatite could transform to soluble phosphate due to the secreted organic acids, then reacted with Pb(II) to form pyromorphite [Pb10(PO4)6Cl2] and lead phosphate hydroxide [Pb10(PO4)6(OH)2]. The overall results clearly demonstrated that combining P. chrysosporium with HAP could be used as a promising technology to accelerate lead immobilization.
Collapse
Affiliation(s)
- Ni He
- School of Minerals Processing and Bioengineering, Key Laboratory of Biohydrometallurgy of Ministry of Education, Central South University, Changsha 410083, China
| | - Liang Hu
- School of Minerals Processing and Bioengineering, Key Laboratory of Biohydrometallurgy of Ministry of Education, Central South University, Changsha 410083, China.
| | - Zhiguo He
- School of Minerals Processing and Bioengineering, Key Laboratory of Biohydrometallurgy of Ministry of Education, Central South University, Changsha 410083, China
| | - Mengke Li
- School of Minerals Processing and Bioengineering, Key Laboratory of Biohydrometallurgy of Ministry of Education, Central South University, Changsha 410083, China
| | - Yongji Huang
- School of Minerals Processing and Bioengineering, Key Laboratory of Biohydrometallurgy of Ministry of Education, Central South University, Changsha 410083, China
| |
Collapse
|
20
|
Lobo GP, Laraway J, Gadgil AJ. Identifying schools at high-risk for elevated lead in drinking water using only publicly available data. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 803:150046. [PMID: 34525701 DOI: 10.1016/j.scitotenv.2021.150046] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/26/2021] [Accepted: 08/26/2021] [Indexed: 06/13/2023]
Abstract
Estimating the risk of lead contamination of schools' drinking water at the State level is a complex, important, and unexplored challenge. Variable water quality among water systems and changes in water chemistry during distribution affect lead dissolution rates from pipes and fittings. In addition, the locations of lead-bearing plumbing materials are uncertain. We tested the capability of six machine learning models to predict the likelihood of lead contamination of drinking water at the schools' taps using only publicly available datasets. The predictive features used in the models correspond to those with a proven correlation to the dominant, but commonly unavailable, factors that govern lead leaching: the presence of lead-bearing plumbing materials and water quality conducive to lead corrosion. By combining water chemistry data from public reports, socioeconomic information from the US census, and spatial features using Geographic Information Systems, we trained and tested models to estimate the likelihood of lead contaminated tap water in over 8,000 schools across California and Massachusetts. Our best-performing model was a Random Forest, with a 10-fold cross validation score of 0.88 for Massachusetts and 0.78 for California using the average Area Under the Receiver Operating Characteristic Curve (ROC AUC) metric. The model was then used to assign a lead leaching risk category to half of the schools across California (the other half was used for training). There was good agreement between the modeled risk categories and the actual lead leaching outcomes for every school; however, the model overestimated the lead leaching risk in up to 17% of the schools. This model is the first of its kind to offer a tool to predict the risk of lead leaching in schools at the State level. Further use of this model can help deploy limited resources more effectively to prevent childhood lead exposure from school drinking water.
Collapse
Affiliation(s)
- G P Lobo
- Department of Civil and Environmental Engineering, University of California, Berkeley 94720, United States
| | - J Laraway
- Department of Environmental Science, Policy and Management, University of California, Berkeley 94720, United States
| | - A J Gadgil
- Department of Civil and Environmental Engineering, University of California, Berkeley 94720, United States.
| |
Collapse
|
21
|
Huseinov A, Weese BL, Brewer BJ, Alvarez NT. Near-electrode pH change for voltammetric detection of insoluble lead carbonate. Anal Chim Acta 2021; 1186:339087. [PMID: 34756248 DOI: 10.1016/j.aca.2021.339087] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 09/14/2021] [Accepted: 09/18/2021] [Indexed: 11/19/2022]
Abstract
Lead contamination of drinking water is a concern to all inhabitants of old cities where lead pipes and soldering are still present. Simple on-site electrochemical detection methods are promising technologies that have gained attention recently. However, conventional electrochemical techniques only quantify soluble forms of lead in water without accounting for insoluble particulates. Herein, a simple voltammetric technique for quantification of insoluble lead species is reported. Lead carbonate (PbCO3) was used as a model compound to show the possibility of detecting particulate lead species directly in solution without chemical treatment. Specifically, electrochemical generation of protons was used as an alternative method to dissolve PbCO3 and thus obtain a more realistic assessment of lead contamination. Lead was detected using cathodic stripping square wave voltammetry (CSSWV). After applying a high oxidizing potential to the electrode immersed in a PbCO3 solution with solid PbCO3 particulates, a significant increase in current was observed as compared to that of a saturated PbCO3 solution. The signal was proportional to the amount of added PbCO3, even when the solubility limit was exceeded. Thus, the combination of a local pH change with CSSWV provides a simple, rapid, and reagentless method for an in-situ detection of insoluble lead species.
Collapse
Affiliation(s)
- Artur Huseinov
- Department of Chemistry, University of Cincinnati, Cincinnati, OH, 45221, United States
| | - Benjamin L Weese
- Department of Chemistry, University of Cincinnati, Cincinnati, OH, 45221, United States
| | - Brody J Brewer
- Department of Chemistry, University of Cincinnati, Cincinnati, OH, 45221, United States
| | - Noe T Alvarez
- Department of Chemistry, University of Cincinnati, Cincinnati, OH, 45221, United States.
| |
Collapse
|
22
|
Carbinatti C, da Conceição FT, Moruzzi RB, Menegário AA. Functionalization of kaolinite for removal of phosphate from urban sewage. MethodsX 2021; 8:101423. [PMID: 34430318 PMCID: PMC8374487 DOI: 10.1016/j.mex.2021.101423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 06/17/2021] [Indexed: 11/22/2022] Open
Abstract
The PO4 3- widespread in urban sewages promotes eutrophication of water sources, with harmful effects to natural life and endanger human health. The removal of PO4 3- from urban sewage requires treatment at tertiary level, with high costs and low efficiency in most cases. Thus, a functionalization method for surface modification of kaolinite was proposed to improve the removal of PO4 3- from urban sewage. The kaolinite commercial did not remove PO4 3- from aqueous solution. However, the functionalized kaolinite (FK) was efficient, with a maximum removal capacity of 8.4 ± 0.1 mg PO4 3-/L, within less than 1 min of reaction. The removal of PO4 3- is associated with precipitation of pyromorphite, a mineral with low solubility (Ksp < 10-79,6). Finally, real urban sewage samples (raw and treated) were also tested for removal of PO4 3- using FK, confirming its effectiveness. The central aspects of this development are:•Functionalized kaolinite (FK), with Pb(II), for removal of PO4 3- from urban sewage was studied.•The FK was efficient for removal of up to 8.4 mg PO4 3-/L from aqueous solution, within a short reaction time.•The precipitation of pyromorphite was the mechanism responsible for removal of PO4 3- and FK efficiency have been confirmed for real urban sewage samples.
Collapse
Affiliation(s)
- Camilla Carbinatti
- UNESP - Universidade Estadual Paulista, Instituto de Geociências e Ciências Exatas, Avenida 24-A, no 1515, CEP 13506-900, Bela Vista, Rio Claro, São Paulo, Brazil
| | - Fabiano Tomazini da Conceição
- UNESP - Universidade Estadual Paulista, Instituto de Geociências e Ciências Exatas, Avenida 24-A, no 1515, CEP 13506-900, Bela Vista, Rio Claro, São Paulo, Brazil
| | - Rodrigo Braga Moruzzi
- UNESP - Universidade Estadual Paulista, Instituto de Geociências e Ciências Exatas, Avenida 24-A, no 1515, CEP 13506-900, Bela Vista, Rio Claro, São Paulo, Brazil
| | | |
Collapse
|
23
|
Pb Mineral Precipitation in Solutions of Sulfate, Carbonate and Phosphate: Measured and Modeled Pb Solubility and Pb2+ Activity. MINERALS 2021. [DOI: 10.3390/min11060620] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Lead (Pb) solubility is commonly limited by dissolution–precipitation reactions of secondary mineral phases in contaminated soils and water. In the research described here, Pb solubility and free Pb2+ ion activities were measured following the precipitation of Pb minerals from aqueous solutions containing sulfate or carbonate in a 1:5 mole ratio in the absence and presence of phosphate over the pH range 4.0–9.0. Using X-ray diffraction and Fourier-transform infrared spectroscopic analysis, we identified anglesite formed in sulfate-containing solutions at low pH. At higher pH, Pb carbonate and carbonate-sulfate minerals, hydrocerussite and leadhillite, were formed in preference to anglesite. Precipitates formed in the Pb-carbonate systems over the pH range of 6 to 9 were composed of cerussite and hydrocerussite, with the latter favored only at the highest pH investigated. The addition of phosphate into the Pb-sulfate and Pb-carbonate systems resulted in the precipitation of Pb3(PO4)2 and structurally related pyromorphite minerals and prevented Pb sulfate and carbonate mineral formation. Phosphate increased the efficiency of Pb removal from solution and decreased free Pb2+ ion activity, causing over 99.9% of Pb to be precipitated. Free Pb2+ ion activities measured using the ion-selective electrode revealed lower values than predicted from thermodynamic constants, indicating that the precipitated minerals may have lower KSP values than generally reported in thermodynamic databases. Conversely, dissolved Pb was frequently greater than predicted based on a speciation model using accepted thermodynamic constants for Pb ion-pair formation in solution. The tendency of the thermodynamic models to underestimate Pb solubility while overestimating free Pb2+ activity in these systems, at least in the higher pH range, indicates that soluble Pb ion-pair formation constants and KSP values need correction in the models.
Collapse
|
24
|
Aghasadeghi K, Peldszus S, Trueman BF, Mishrra A, Cooke MG, Slawson RM, Giammar DE, Gagnon GA, Huck PM. Pilot-scale comparison of sodium silicates, orthophosphate and pH adjustment to reduce lead release from lead service lines. WATER RESEARCH 2021; 195:116955. [PMID: 33714013 DOI: 10.1016/j.watres.2021.116955] [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: 10/30/2020] [Revised: 02/01/2021] [Accepted: 02/17/2021] [Indexed: 06/12/2023]
Abstract
Sodium silicate is thought to mitigate lead release via two mechanisms: by increasing pH and by forming a protective silica film. A pilot-scale study using an excavated lead service line (LSL) fed with water from a Great Lakes source was undertaken to: (1) clearly distinguish the pH effect and the silica effect; (2) compare sodium silicate to orthophosphate and pH adjustment; (3) determine the nature of silica accumulation in the pipe scale. The LSL was cut into segments and acclimated with water at pH 7.1. Median dissolved lead was 197 µg/L in the last 8 weeks of acclimation and dropped to 16 µg/L, 54 µg/L, and 85 µg/L following treatment with orthophosphate (dose: 2.6 mg-PO4/L, pH: 7.9), pH adjustment (pH: 7.9) and sodium silicate (dose: 20 mg-SiO2/L, pH: 7.9), respectively. When silica dose was increased from 20 mg-SiO2/L to 25 mg-SiO2/L (pH: 8.1), lead release destabilized and increased (median dissolved lead: 141 µg/L) due to formation of colloidal dispersions composed mainly of lead- and aluminum-rich phases as detected by field flow fractionation used with inductively coupled plasma mass spectrometry. Si was present in the scale at a maximum of 2.2 atomic % after 17 weeks of silica dosing at 20 mg- SiO2/L. Under the conditions tested, sodium silicate did not offer any benefits for reducing lead release from this LSL other than increasing pH. However, sodium silicate resulted in lower levels of biofilm accumulation on pipe walls, as measured by heterotrophic plate counts, when compared to orthophosphate.
Collapse
Affiliation(s)
- Kimia Aghasadeghi
- Department of Civil and Environmental Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
| | - Sigrid Peldszus
- Department of Civil and Environmental Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Benjamin F Trueman
- Department of Civil & Resource Engineering, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Anushka Mishrra
- Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, USA
| | - Mitchell G Cooke
- Department of Biology, Wilfrid Laurier University, Waterloo, Ontario, N2L 3C5, Canada
| | - Robin M Slawson
- Department of Biology, Wilfrid Laurier University, Waterloo, Ontario, N2L 3C5, Canada
| | - Daniel E Giammar
- Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, USA
| | - Graham A Gagnon
- Department of Civil & Resource Engineering, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Peter M Huck
- Department of Civil and Environmental Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| |
Collapse
|
25
|
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.
Collapse
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
| |
Collapse
|
26
|
Wei J, Duan L, Wei J, Hoffmann E, Song Y, Meng X. Lead removal from water using organic acrylic amine fiber (AAF) and inorganic-organic P-AAF, fixed bed filtration and surface-induced precipitation. J Environ Sci (China) 2021; 101:135-144. [PMID: 33334509 DOI: 10.1016/j.jes.2020.08.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/11/2020] [Accepted: 08/11/2020] [Indexed: 06/12/2023]
Abstract
Granular porous sorbents were normally used for heavy metals removal from water. To search for the new commercial sorbent and treatment strategy, an organic acrylic amine fiber (AAF) and phosphorus loading inorganic-organic AAF (P-AAF) were prepared and used for lead (Pb) removal from water. A new strategy of inorganic-organic coupling technology was proposed for Pb removal, based on the hypothesis of surface-induced precipitation mechanism. The AAF showed a Pb adsorption capacity of 417 mg/g from the Langmuir fitting, while the column filtration technology was further applied to measure the adsorption edge and applications. Effects of different initial Pb concentrations, hydraulic retention time, and co-existing P were considered in the filtration experiments. The presence of 0.8 mg/L P in water significantly improved the Pb breakthrough point from 15,000 to 41,000 bed volumes of water spiked with 85 µg/L Pb, while the P-AAF fixed bed showed better removal of Pb than AAF SEM/EDX and XRD spectra were employed for determining the surface functional groups and the formation of surface-induced precipitation of pyromorphite (Pb5(PO4)3OH) on AAF. This study verified the application of AAF sorbent for Pb removal and the enhanced effect of coating P on AAF, thus improved our fundamental understanding and application of the surface chemistry process of Pb with P.
Collapse
Affiliation(s)
- Jinshan Wei
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Center for Environmental Systems, Stevens Institute of Technology, Hoboken, NJ 07030, USA; School of Environment, Tsinghua University, Beijing 100084, China.
| | - Lijie Duan
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; School of Environment, Tsinghua University, Beijing 100084, China
| | - Jian Wei
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Erhard Hoffmann
- Department of Aquatic Environmental Engineering, Karlsruhe Institute of Technology, Karsruhe 76131, Germany
| | - Yonghui Song
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Xiaoguang Meng
- Center for Environmental Systems, Stevens Institute of Technology, Hoboken, NJ 07030, USA.
| |
Collapse
|
27
|
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.
Collapse
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.
| |
Collapse
|
28
|
Zhou Y, Li X, McBride MB. Aqueous solubility of Pb at equilibrium with hydroxypyromorphite over a range of phosphate concentrations. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2021; 23:170-178. [PMID: 33399599 DOI: 10.1039/d0em00430h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Hydroxypyromorphite (HPM) is a low-solubility Pb phosphate mineral that has the potential to limit solubility and bioavailability of Pb in soils and water. Because of reported uncertainty regarding the solubility product of this important mineral, we re-evaluated the solubility of Pb and activity of the free Pb2+ ion in aqueous suspensions of microcrystalline HPM equilibrated up to 30 days over a wide range of added soluble phosphate. A small addition of phosphate (0.1 mM) reduced Pb solubility as measured by ICP-OES, but greater phosphate additions (up to 50 mM) had no further effect in lowering HPM solubility. However, free Pb2+ ion activity measured by ion-selective electrode progressively decreased from about 10-6.5 with no added phosphate to 10-9 as soluble phosphate was increased. The effect of soluble phosphate in lowering Pb2+ activity is attributed to inhibited dissolution of HPM as well as increased Pb2+-phosphate ion pair formation in solution at higher solution concentrations of phosphate. Measurement of the ion activity products (IAP) of the solutions at equilibrium with HPM gave highly variable IAP values that were sensitive to pH and were generally not consistent with the reported solubility product of this mineral. The high variability of the IAPs for solutions with variable pH and phosphate concentrations indicates that dissolution-precipitation reactions of HPM are not described by a constant solubility product at equilibrium, possibly because of the incongruent dissolution behavior of this mineral at near-neutral pH.
Collapse
Affiliation(s)
- Yuting Zhou
- College of Environmental and Resource Science, Zhejiang University, Hangzhou, China
| | - Xinxin Li
- School of Environmental Science and Engineering, Shandong University, Qingdao, China
| | - Murray B McBride
- Section of Soil and Crop Sciences, Cornell University, Ithaca, NY 14850, USA.
| |
Collapse
|
29
|
Meng X, Hu R. Nitrogen/phosphorus enriched biochar with enhanced porosity activated by guanidine phosphate for efficient passivation of Pb(II), Cu(II) and Cd(II). J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.115071] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
30
|
Afzal MJ, Khan MI, Cheema SA, Hussain S, Anwar-Ul-Haq M, Ali MH, Naveed M. Combined application of Bacillus sp. MN-54 and phosphorus improved growth and reduced lead uptake by maize in the lead-contaminated soil. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:44528-44539. [PMID: 32772285 DOI: 10.1007/s11356-020-10372-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 08/03/2020] [Indexed: 06/11/2023]
Abstract
Lead (Pb) is considered an important environmental contaminant due to its considerable toxicity to living organisms. It can enter and accumulate in plant tissues and become part of the food chain. In the present study, individual and combined effects of Bacillus sp. MN-54 and phosphorus (P) on maize growth and physiology were evaluated in Pb-contaminated soil. A pristine soil was artificially contaminated with two levels of Pb (i.e., 250 and 500 mg kg-1 dry soil) and was transferred to plastic pots. Bacillus sp. MN-54 treated and untreated maize (DK-6714) seeds were planted in pots. Recommended doses of nutrients (N and K) were applied in each pot while P was applied in selective pots. Results showed that Pb stress hampered the maize growth and physiological attributes in a concentration-dependent manner, and significant reductions in seedling emergence, shoot and root lengths, fresh and dry biomasses, leaf area, chlorophyll content, rate of photosynthesis, and stomatal conductance were recorded compared with control. Application of Bacillus sp. MN-54 or P particularly in combination significantly reduced the toxic effects of Pb on maize. At higher Pb level (500 mg kg-1), the combined application effectively reduced Pb uptake up to 42.4% and 50% by shoots, 30.8% and 33.9% by roots, and 18.4% and 26.2% in available Pb content in soil after 45 days and 90 days, respectively compared with that of control. Moreover, the use of Bacillus sp. MN-54 significantly improved the P uptake by maize plants by 44.4% as compared with that of control. Our findings suggest that the combined use of Bacillus sp. MN-54 and P could be effective and helpful in improving plant growth and Pb immobilization in Pb-contaminated soil.
Collapse
Affiliation(s)
- Muhammad Junaid Afzal
- Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad, Pakistan
| | - Muhammad Imran Khan
- Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad, Pakistan.
- Department of Isotope Biogeochemistry, Helmholtz - Center for Environmental Research-UFZ, Leipzig, Germany.
| | | | - Saddam Hussain
- Department of Agronomy, University of Agriculture, Faisalabad, Pakistan
| | - Muhammad Anwar-Ul-Haq
- Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad, Pakistan
| | - Muhammad Hayder Ali
- Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad, Pakistan
| | - Muhammad Naveed
- Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad, Pakistan
| |
Collapse
|
31
|
Zhang S, Shi Q, Chou TM, Christodoulatos C, Korfiatis GP, Meng X. Mechanistic Study of Pb(II) Removal by TiO 2 and Effect of PO 4. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:13918-13927. [PMID: 33171040 DOI: 10.1021/acs.langmuir.0c02388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
As a commercial adsorbent, TiO2 shows a high adsorption capacity for lead (Pb(II)). However, the molecular structure of Pb(II) adsorption on TiO2 is still unknown. Meanwhile, as a widely used corrosion inhibitor, phosphate (PO4) is usually added into drinking water, and its influential mechanism on Pb(II) removal by TiO2 remains unknown. Here, the mechanisms of Pb(II) adsorption on TiO2 and the effect of PO4 were systematically investigated using a combination of spectroscopic analyses and surface complexation modeling. The adsorption structure of Pb(II) on TiO2 was revealed as a tridentate mononuclear configuration by the extended X-ray absorption fine structure (EXAFS) analysis. In the presence of 0.1-5 mg/L PO4, Pb(II) was removed mainly by adsorption on TiO2 rather than precipitation. Ternary complexation between Pb(II) and PO4 on TiO2 surfaces was found based on EXAFS and in situ Fourier transform infrared characterizations. These complexation structures were used to build a surface complexation model to accurately simulate and predict Pb(II) removal under different conditions. This study provides essential information about the mechanisms of Pb(II) removal by TiO2 and develops a model to predict adsorption behaviors, especially in the presence of PO4.
Collapse
Affiliation(s)
- Shujuan Zhang
- Center for Environmental Systems, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| | - Qiantao Shi
- Center for Environmental Systems, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| | - Tseng-Ming Chou
- Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| | - Christos Christodoulatos
- Center for Environmental Systems, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| | - George P Korfiatis
- Center for Environmental Systems, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| | - Xiaoguang Meng
- Center for Environmental Systems, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| |
Collapse
|
32
|
Lytle DA, Schock MR, Formal C, Bennett-Stamper C, Harmon S, Nadagouda MN, Williams D, DeSantis MK, Tully J, Pham M. Lead Particle Size Fractionation and Identification in Newark, New Jersey's Drinking Water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:13672-13679. [PMID: 33089978 PMCID: PMC7702024 DOI: 10.1021/acs.est.0c03797] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Following a pH reduction in their drinking water over a span of more than 20 years, the City of Newark, New Jersey, has struggled with elevated lead (Pb) release from Pb service lines and domestic plumbing in the zone fed by the Pequannock Water Treatment Plant. In response, Newark initiated orthophosphate addition and provided faucet-mounted point-of-use (POU) filters and pitcher filters certified for Pb and particulate reduction under NSF/ANSI Standards 53 and 42 to residential homes in that zone. Water chemistry analysis and size fractionation sampling were performed at four of these houses. Analysis of the particulate material retained by the fractionation filters revealed that Pb was dominantly present in the water as fine Pb(II) orthophosphate particles. A considerable amount of the particulates occurred as a nanoscale fraction that sometimes passed through the POU faucet or pitcher filtration units. Scanning electron microscopy, transmission electron microscopy, and energy-dispersive spectroscopy analyses showed that the nanoparticles (<100 nm) and their aggregates were composed of Pb, phosphorus, and chlorine, which are consistent with pyromorphite, Pb5(PO4)3Cl. Electron diffraction and X-ray analyses supported the presence of hydroxypyromorphite and chloropyromorphite nanoparticles and the size range estimates from the imaging. This research confirmed that nonadherent Pb(II)-orthophosphate nanoparticles were an important form of Pb in drinking water in the Pequannock water quality zone of Newark.
Collapse
Affiliation(s)
- Darren A Lytle
- Office of Research and Development, Drinking Water Management Branch, Center for Environmental Solutions & Emergency Response, Water Infrastructure Division, U.S. Environmental Protect Agency, 26W. Martin Luther King Dr., Cincinnati, Ohio 45268, United States
| | - Michael R Schock
- Office of Research and Development, Drinking Water Management Branch, Center for Environmental Solutions & Emergency Response, Water Infrastructure Division, U.S. Environmental Protect Agency, 26W. Martin Luther King Dr., Cincinnati, Ohio 45268, United States
| | - Casey Formal
- Office of Research and Development, Center for Environmental Solutions & Emergency Response, Water Infrastructure Division, Oak Ridge Associated Universities (ORAU) Student Services Contractor to the U.S. Environmental Protect Agency, Cincinnati 45268, United States
| | - Christina Bennett-Stamper
- Office of Research and Development, Drinking Water Management Branch, Center for Environmental Solutions & Emergency Response, Water Infrastructure Division, U.S. Environmental Protect Agency, 26W. Martin Luther King Dr., Cincinnati, Ohio 45268, United States
| | - Stephen Harmon
- Office of Research and Development, Drinking Water Management Branch, Center for Environmental Solutions & Emergency Response, Water Infrastructure Division, U.S. Environmental Protect Agency, 26W. Martin Luther King Dr., Cincinnati, Ohio 45268, United States
| | - Mallikarjuna N Nadagouda
- Office of Research and Development, Drinking Water Management Branch, Center for Environmental Solutions & Emergency Response, Water Infrastructure Division, U.S. Environmental Protect Agency, 26W. Martin Luther King Dr., Cincinnati, Ohio 45268, United States
| | - Daniel Williams
- Office of Research and Development, Drinking Water Management Branch, Center for Environmental Solutions & Emergency Response, Water Infrastructure Division, U.S. Environmental Protect Agency, 26W. Martin Luther King Dr., Cincinnati, Ohio 45268, United States
| | - Michael K DeSantis
- Office of Research and Development, Drinking Water Management Branch, Center for Environmental Solutions & Emergency Response, Water Infrastructure Division, U.S. Environmental Protect Agency, 26W. Martin Luther King Dr., Cincinnati, Ohio 45268, United States
| | - Jennifer Tully
- Office of Research and Development, Drinking Water Management Branch, Center for Environmental Solutions & Emergency Response, Water Infrastructure Division, U.S. Environmental Protect Agency, 26W. Martin Luther King Dr., Cincinnati, Ohio 45268, United States
| | - Maily Pham
- Office of Research and Development, Center for Environmental Solutions & Emergency Response, Water Infrastructure Division, U.S. Environmental Protect Agency, 26W. Martin Luther King Dr., Cincinnati, Ohio 45268, United States
| |
Collapse
|
33
|
Wei J, Meng X, Song Y, Shi Q, Wen X, Korfiatis G. Surface mole-ratio method to distinguish surface precipitation and adsorption on solid-liquid interface. JOURNAL OF HAZARDOUS MATERIALS 2020; 397:122781. [PMID: 32388096 DOI: 10.1016/j.jhazmat.2020.122781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 04/16/2020] [Accepted: 04/18/2020] [Indexed: 06/11/2023]
Abstract
The enhancement effects of phosphate (P) on Pb removal by adsorbents have been attributed to co-adsorption of P and Pb, the formation of P-Pb surface ternary surface complexes, and surface precipitation of P and Pb. However, distinguishing adsorption from surface precipitation in multi-adsorbate systems has been a challenge. For the first time, a surface mole-ratio (SMR) method was established and applied for delineating Pb-P precipitation and Pb adsorption on an acrylic amine fiber (AAF) adsorbent. In elaborating the SMR method, we developed Pb removal experiments by mixing solutions containing 0.2 g/L of AAF, 6 and 12 μmol/L P, and 0-35 μmol/L Pb. When the removed Pb/P (μmol/μmol) was plotted as a function of the equilibrium Pb (μmol/L), the SMR diagram exhibited a turning-point similar to the Pb/P mole ratio of 5/3 = 1.67 in pyromorphite (Pb5(PO4)3OH) precipitate. The SMR diagram indicated that when the Pb concentration increased, the precipitate formed first; after all P formed precipitates, Pb was removed by adsorption. The precipitation and adsorption processes were further confirmed by other SMR diagrams, FTIR, SEM-EDX, and XRD analysis. The SMR method will have broad applications in determining the removal mechanisms of multi-adsorbates by adsorbents and coagulants, and stabilization mechanisms of heavy metals in soils. With the development and application of more modern in-situ characterization techniques, SMR method will be more effective.
Collapse
Affiliation(s)
- Jinshan Wei
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China.
| | - Xiaoguang Meng
- Center for Environmental Systems, Stevens Institute of Technology, Hoboken, NJ, USA.
| | - Yonghui Song
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China.
| | - Qiantao Shi
- Center for Environmental Systems, Stevens Institute of Technology, Hoboken, NJ, USA
| | - Xianghua Wen
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
| | - George Korfiatis
- Center for Environmental Systems, Stevens Institute of Technology, Hoboken, NJ, USA
| |
Collapse
|
34
|
Shi Q, Zhang S, Ge J, Wei J, Christodoulatos C, Korfiatis GP, Meng X. Lead immobilization by phosphate in the presence of iron oxides: Adsorption versus precipitation. WATER RESEARCH 2020; 179:115853. [PMID: 32388052 DOI: 10.1016/j.watres.2020.115853] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 04/14/2020] [Accepted: 04/18/2020] [Indexed: 06/11/2023]
Abstract
As a commonly used corrosion inhibitor, phosphate (PO4) has a complicated effect on the fate and transport of lead (Pb) in drinking water systems. While the formation of pyromorphite has been recognized to be the major driving force of the Pb immobilization mechanism, the role of adsorption on iron oxides is still not clear. This study aims to clarify the contributions of adsorption and precipitation to Pb removal in a system containing both iron oxides and PO4. A combination of batch experiments, X-ray absorption spectroscopy, infrared spectroscopy, and electron spectroscopy was employed to distinguish the adsorbed and precipitated Pb species. The results indicated that the adsorption of Pb on iron oxides still occurred even when the solution was supersaturated to pyromorphite (i.e., 5 mg/L P with 0.1-30 mg/L Pb in 0.01 M NaCl solution at neutral pH). In the tap water containing 0.92 mg/L P and 1 mg/L Pb, adsorption on iron oxides contributed more (62-67%) than precipitation (33-38%) in terms of Pb removal. Surprisingly, the pre-formed pyromorphite is transformed to adsorbed species after mixing with iron oxides in water for 24 h. The illustration of this transformation is important to understand the immobilization mechanisms and transport behaviors of Pb in drinking water systems after the utilization of PO4.
Collapse
Affiliation(s)
- Qiantao Shi
- Center for Environmental Systems, Stevens Institute of Technology, Hoboken, NJ, 07030, United States
| | - Shujuan Zhang
- Center for Environmental Systems, Stevens Institute of Technology, Hoboken, NJ, 07030, United States
| | - Jie Ge
- Center for Environmental Systems, Stevens Institute of Technology, Hoboken, NJ, 07030, United States
| | - Jinshan Wei
- Center for Environmental Systems, Stevens Institute of Technology, Hoboken, NJ, 07030, United States
| | - Christos Christodoulatos
- Center for Environmental Systems, Stevens Institute of Technology, Hoboken, NJ, 07030, United States
| | - George P Korfiatis
- Center for Environmental Systems, Stevens Institute of Technology, Hoboken, NJ, 07030, United States
| | - Xiaoguang Meng
- Center for Environmental Systems, Stevens Institute of Technology, Hoboken, NJ, 07030, United States. http://
| |
Collapse
|
35
|
Li G, Bae Y, Mishrra A, Shi B, Giammar DE. Effect of Aluminum on Lead Release to Drinking Water from Scales of Corrosion Products. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:6142-6151. [PMID: 32338882 DOI: 10.1021/acs.est.0c00738] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The occurrence of aluminum in scales on lead pipes is common. This study aimed to identify factors that influence Al accumulation on oxidized lead surfaces and to determine whether the presence of Al impacts Pb release from corrosion products to water. Al accumulation and Pb release were monitored both with and without the addition of phosphate as a corrosion inhibitor. Pb coupons with corrosion scales were exposed to chlorinated water for up to 198 days to investigate Al accumulation and Pb release. Al accumulation was facilitated by Pb corrosion products, but its accumulation was inhibited by phosphate addition. During the study period, the formation of Al deposits did not affect Pb release when phosphate was absent. In an Al-free system, the addition of 1.0 mg/L phosphate (as P) lowered the dissolved Pb concentration below 1.0 μg/L. In a system containing 200 μg/L Al, the emergence of phosphate's effect on Pb control was delayed, and the dissolved Pb concentration decreased but stabilized at a higher value (10-12 μg/L) than in the Al-free system. Phosphohedyphane (Ca2Pb3(PO4)3Cl) was formed in all phosphate-containing systems, and PbO2 was formed independent of phosphate addition. The effect of Al on Pb release was probably related to its influence on the composition and morphology of Pb-containing minerals on coupon surfaces. The laboratory study has unavoidable limitations in its ability to simulate all conditions in real lead service lines, but this study still highlights the importance of considering the influence of Al when designing Pb corrosion control strategies.
Collapse
Affiliation(s)
- Guiwei Li
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yeunook Bae
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Anushka Mishrra
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Baoyou Shi
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Daniel E Giammar
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| |
Collapse
|
36
|
Liao P, Pan C, Ding W, Li W, Yuan S, Fortner JD, Giammar DE. Formation and Transport of Cr(III)-NOM-Fe Colloids upon Reaction of Cr(VI) with NOM-Fe(II) Colloids at Anoxic-Oxic Interfaces. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:4256-4266. [PMID: 32163701 DOI: 10.1021/acs.est.9b07934] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Natural organic matter-iron (NOM-Fe) colloids are ubiquitous at anoxic-oxic interfaces of subsurface environments. Fe(II) or NOM can chemically reduce Cr(VI) to Cr(III), and the formation of Cr(III)-NOM-Fe colloids can control the fate and transport of Cr. We explored the formation and transport of Cr(III)-humic acid (HA)-Fe colloids upon reaction of Cr(VI) with HA-Fe(II) colloids over a range of environmentally relevant conditions. Cr(VI) was completely reduced by HA-Fe(II) complexes under anoxic conditions, and the formation of Cr(III)-HA-Fe colloids depended on HA concentration (or molar C/Fe ratio) and redox conditions. No colloids formed at HA concentrations below 3.5 mg C/L (C/Fe ratio below 1.6), but Cr(III)-HA-Fe colloids formed at higher HA concentrations. In column experiments, Cr(III)-HA-Fe(III) colloids formed under oxic conditions were readily transported through sand-packed porous media. Colloidal stability measurements further suggest that Cr(III)-HA-Fe colloids are highly stable and persist for at least 20 days without substantial change in particle size. This stability is attributed to the enrichment of free HA adsorbed on the Cr(III)-HA-Fe colloid surfaces, intensifying the electrostatic and/or steric repulsion interactions between particles. The new insights provided here are important for evaluating the long-term fate and transport of Cr in organic-rich redox transition zones.
Collapse
Affiliation(s)
- Peng Liao
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, NO. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, 430074, P. R. China
- Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
- State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, P. R. China
| | - Chao Pan
- Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Wenyu Ding
- Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Wenlu Li
- Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, United States
| | - Songhu Yuan
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, NO. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, 430074, P. R. China
| | - John D Fortner
- Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, United States
| | - Daniel E Giammar
- Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| |
Collapse
|
37
|
Abokifa AA, Katz L, Sela L. Spatiotemporal trends of recovery from lead contamination in Flint, MI as revealed by crowdsourced water sampling. WATER RESEARCH 2020; 171:115442. [PMID: 31927093 DOI: 10.1016/j.watres.2019.115442] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 12/20/2019] [Accepted: 12/23/2019] [Indexed: 06/10/2023]
Abstract
In the aftermath of the lead contamination crisis that plagued the water system in Flint, MI, more than 35,000 water samples were collected from the city's premises. The majority of these samples (>85%) were collected through a voluntary crowdsourced sampling campaign. The samples were analyzed for lead and copper concentrations by the Michigan Department of Environmental Quality (MDEQ). In this study, the crowdsourced sampling data was analyzed by means of spatial autocorrelation analysis to reveal the locations of statistically significant hotspot regions of high water lead levels (WLLs), and to track the spatiotemporal evolution of WLLs as the system recovered from lead contamination. The results showed that hotspot regions that experienced high WLLs were consistent with the areas where lead service line (LSL) density was the highest. Additionally, galvanized service lines and other lead-containing plumbing components could have also contributed to lead release in hotspot regions. The temporal trend exhibited by the crowdsourced sampling data did not reflect a consistent decrease in WLLs despite the interventions implemented by MDEQ and EPA. Instead, sampled WLLs remained high for several months after boosting the orthophosphate dose and launching a city-wide residential flushing campaign. The findings of this study suggest that this could be partially attributed to disproportionate sampling from premises in hotspot regions of high WLLs and LSL density.
Collapse
Affiliation(s)
- Ahmed A Abokifa
- Department of Civil, Architectural and Environmental Engineering, University of Texas at Austin, 10100 Burnet Rd, MC R8000, Austin, TX, 78750, USA.
| | - Lynn Katz
- Department of Civil, Architectural and Environmental Engineering, University of Texas at Austin, 10100 Burnet Rd, MC R8000, Austin, TX, 78750, USA
| | - Lina Sela
- Department of Civil, Architectural and Environmental Engineering, University of Texas at Austin, 10100 Burnet Rd, MC R8000, Austin, TX, 78750, USA
| |
Collapse
|
38
|
Gora SL, Trueman BF, Anaviapik-Soucie T, Gavin MK, Ontiveros CC, Campbell J, L'Hérault V, Stoddart AK, Gagnon GA. Source Water Characteristics and Building-specific Factors Influence Corrosion and Point of Use Water Quality in a Decentralized Arctic Drinking Water System. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:2192-2201. [PMID: 31961665 DOI: 10.1021/acs.est.9b04691] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Access to clean and safe drinking water is a perpetual concern in Arctic communities because of challenging climatic conditions, limited options for the transportation of equipment and process chemicals, and the ongoing effects of colonialism. Water samples were gathered from multiple locations in a decentralized trucked drinking water system in Nunavut, Canada, over the course of one year. The results indicate that point of use drinking water quality was impacted by conditions in the source water and in individual buildings and strongly suggest that lead and copper measured at the tap were related to corrosion of onsite premise plumbing components. Humic-like substances were the dominant organic fraction in all samples, as determined by regional integration of fluorescence data. Iron and manganese levels in the source water and throughout the water system were higher in the winter and lower in the summer months. Elevated concentrations of copper (>2000 μg L-1) and lead (>5 μg L-1) were detected in tap water from some buildings. Field flow fractionation coupled with inductively coupled plasma mass spectrometry and ultraviolet-visible spectrometry was used to demonstrate the link between source water characteristics (high organics, iron and manganese) and lead and copper in point of use drinking water.
Collapse
Affiliation(s)
- Stephanie L Gora
- Department of Civil and Resource Engineering , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
| | - Benjamin F Trueman
- Department of Civil and Resource Engineering , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
| | | | - Megan K Gavin
- Nunavut Arctic College , Iqaluit , Nunavut X0A 0H0 , Canada
| | - C Carolina Ontiveros
- Department of Civil and Resource Engineering , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
| | - Jessica Campbell
- Department of Civil and Resource Engineering , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
- Halifax Water , 450 Cowie Hill Rd. , Halifax , Nova Scotia B3P 2V3 , Canada
| | | | - Amina K Stoddart
- Department of Civil and Resource Engineering , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
| | - Graham A Gagnon
- Department of Civil and Resource Engineering , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
| |
Collapse
|
39
|
Trueman BF, Gregory BS, McCormick NE, Gao Y, Gora S, Anaviapik-Soucie T, L'Hérault V, Gagnon GA. Manganese Increases Lead Release to Drinking Water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:4803-4812. [PMID: 30951629 DOI: 10.1021/acs.est.9b00317] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Lead and manganese are regulated in drinking water due to their neurotoxicity. These elements have been reported to co-occur in drinking water systems, in accordance with the metal-scavenging properties of MnO2. To the extent that manganese is a driver of lead release, controlling it during water treatment may reduce lead levels. We investigated transport of lead and manganese at the tap in a full-scale distribution system: consistent with a cotransport phenomenon, the two metals were detected in the same colloidal size fraction by size-exclusion chromatography with multielement detection. We also studied the effect of manganese on lead release using a model distribution system: increasing manganese from 4 to 215 μg L-1 nearly doubled lead release. This effect was attributed primarily to deposition corrosion of lead by oxidized phases of manganese, and we used 16S rRNA sequencing to identify bacteria that may be relevant to this process. We explored the deposition corrosion mechanism by coupling pure lead with either MnO2-coated lead or pure lead exposed to MnO2 in suspension; we observed galvanic currents in both cases. We attributed these to reduction of Mn(IV) under anaerobic conditions, and we attributed the additional current under aerobic conditions to oxygen reduction catalyzed by MnO2.
Collapse
Affiliation(s)
- Benjamin F Trueman
- Department of Civil & Resource Engineering , Dalhousie University , Halifax , NS CAN , B3H 4R2
| | - Brittany S Gregory
- Department of Civil & Resource Engineering , Dalhousie University , Halifax , NS CAN , B3H 4R2
| | - Nicole E McCormick
- Department of Civil & Resource Engineering , Dalhousie University , Halifax , NS CAN , B3H 4R2
| | - Yaohuan Gao
- Department of Civil & Resource Engineering , Dalhousie University , Halifax , NS CAN , B3H 4R2
| | - Stephanie Gora
- Department of Civil & Resource Engineering , Dalhousie University , Halifax , NS CAN , B3H 4R2
| | - Tim Anaviapik-Soucie
- ARCTIConnexion , Québec , QC CAN , G1L 1Y8
- Community of Pond Inlet , Pond Inlet , NU CAN , X0A 0S0
| | | | - Graham A Gagnon
- Department of Civil & Resource Engineering , Dalhousie University , Halifax , NS CAN , B3H 4R2
| |
Collapse
|
40
|
Liu J, Louie SM, Pham C, Dai C, Liang D, Hu Y. Aggregation of ferrihydrite nanoparticles: Effects of pH, electrolytes,and organics. ENVIRONMENTAL RESEARCH 2019; 172:552-560. [PMID: 30856401 DOI: 10.1016/j.envres.2019.03.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 01/28/2019] [Accepted: 03/03/2019] [Indexed: 06/09/2023]
Abstract
To better understand the fate and transport of ferrihydrite nanoparticles (FNPs), which carry many contaminants in natural and engineered aquatic environments, the aggregation of FNPs was systematically investigated in this study. The pH isoelectric point (pHIEP), surface zeta potential, and particle size evolutions of FNPs were measured under varied aqueous conditions using dynamic light scattering (DLS). The influence of pH (5.0 ± 0.1 and 7.0 ± 0.1), ionic strength (IS), electrolytes (NaCl, CaCl2 and Na2SO4), and organics (humic acid, fulvic acid and CH3COONa) on the aggregation behaviors of FNPs were explored. Meanwhile, Derjaguin-Landau-Verwey-Overbeek (DLVO) theory was employed to better understand the controlling mechanisms of FNP aggregation. In the presence of sulfate, the surface charge of FNPs was neutralized under varied pH and ionic strength due to ion adsorption and FNPs phase transformation to schwertmannite based on FT-IR results. This phase transformation resulted in rapid aggregation in all water chemistries tested, whereas other salt species affected the aggregation primarily by ion adsorption and charge screening. Presence of increasing concentrations of the organic acids significantly shifted the pHIEP of FNPs (7.0 ± 0.2) to lower pH (< 4.0) due to adsorption of organics on FNPs surfaces making them negatively charged. The adsorption of HA/FA inhibited FNP aggregation significantly while CH3COONa did not, due to different effects on steric and/or electrosteric interactions among FNPs by organics with varied pKa values and molecular weights. After accounting for the important effects of pH, electrolytes, and organics in modifying FNPs' surface charge, DLVO calculations agreed well with measured critical coagulation concentrations (CCC) values of FNPs at both pH 5.0 ± 0.1 and 7.0 ± 0.1 in the presence of NaCl. This study will hence be useful to better predict and control the fate and transport of FNPs in the presence of electrolytes and organics with different molecular weights, as well as the fate of the associated contaminants in natural and engineered systems.
Collapse
Affiliation(s)
- Juanjuan Liu
- College of Natural Resources and Environment, Northwest A & F University, Yangling, Shaanxi 712100, China; Department of Civil & Environmental Engineering, University of Houston, Houston, TX 77204, United States
| | - Stacey Marie Louie
- Department of Civil & Environmental Engineering, University of Houston, Houston, TX 77204, United States
| | - Christopher Pham
- Department of Civil & Environmental Engineering, University of Houston, Houston, TX 77204, United States
| | - Chong Dai
- Department of Civil & Environmental Engineering, University of Houston, Houston, TX 77204, United States
| | - Dongli Liang
- College of Natural Resources and Environment, Northwest A & F University, Yangling, Shaanxi 712100, China.
| | - Yandi Hu
- Department of Civil & Environmental Engineering, University of Houston, Houston, TX 77204, United States.
| |
Collapse
|