1
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Wang Z, Lü C, Wang Y, Gomes RL, Clarke CJ, Gomes HI. Zero-valent iron (ZVI) facilitated in-situ selenium (Se) immobilization and its recovery by magnetic separation: Mechanisms and implications for microbial ecology. JOURNAL OF HAZARDOUS MATERIALS 2024; 473:134591. [PMID: 38761763 DOI: 10.1016/j.jhazmat.2024.134591] [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: 03/28/2024] [Revised: 05/03/2024] [Accepted: 05/10/2024] [Indexed: 05/20/2024]
Abstract
Selenium (Se(VI)) is environmentally toxic. One of the most popular reducing agents for Se(VI) remediation is zero-valent iron (ZVI). However, most ZVI studies were carried out in water matrices, and the recovery of reduced Se has not been investigated. A water-sediment system constructed using natural sediment was employed here to study in-situ Se remediation and recovery. A combined effect of ZVI and unacclimated microorganisms from natural sediment was found in Se(VI) removal in the water phase with a removal efficiency of 92.7 ± 1.1% within 7 d when 10 mg L-1 Se(VI) was present. Soluble Se(VI) was removed from the water and precipitated to the sediment phase (74.8 ± 0.1%), which was enhanced by the addition of ZVI (83.3 ± 0.3%). The recovery proportion of the immobilized Se was 34.2 ± 0.1% and 92.5 ± 0.2% through wet and dry magnetic separation with 1 g L-1 ZVI added, respectively. The 16 s rRNA sequencing revealed the variations in the microbial communities in response to ZVI and Se, which the magnetic separation could potentially mitigate in the long term. This study provides a novel technique to achieve in-situ Se remediation and recovery by combining ZVI reduction and magnetic separation.
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Affiliation(s)
- Zhongli Wang
- Ministry of Education Key Laboratory of Ecology and Resources Use of the Mongolian Plateau, School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China; Food Water Waste Research Group, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom.
| | - Changwei Lü
- Ministry of Education Key Laboratory of Ecology and Resources Use of the Mongolian Plateau, School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Yanming Wang
- Food Water Waste Research Group, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Rachel L Gomes
- Food Water Waste Research Group, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Coby J Clarke
- Glaxo Smith Kline Carbon Neutral Laboratory for Sustainable Chemistry, University of Nottingham, Nottingham NG7 2GA, United Kingdom
| | - Helena I Gomes
- Food Water Waste Research Group, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
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2
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Meissner MS, Nguyen VHT, Bousrih I, Le VTC, Frickenstein A, Le GV, Bui NT. Thermodynamic insights into selenium oxyanion removal from synthetic flue gas desulfurization wastewater with temperature-swing solvent extraction. Front Chem 2023; 11:1225843. [PMID: 37744061 PMCID: PMC10514578 DOI: 10.3389/fchem.2023.1225843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 08/21/2023] [Indexed: 09/26/2023] Open
Abstract
Temperature-swing solvent extraction (TSSE) is a cost-effective, simple, versatile, and industry-ready technology platform capable of desalinating hypersaline brines toward zero liquid discharge. In this work, we demonstrate the potential of TSSE in the effective removal of selenium oxyanions and traces of mercury with the coexistence of high contents of chloride and sulfate often encountered in flue gas desulfurization wastewater streams. We compare the rejection performance of the two common solvents broadly used for TSSE, decanoic acid (DA) and diisopropylamine (DPA), and correlate those with the solvent physicochemical properties (e.g., dielectric constant, polarity, molecular bulkiness, and hydrophobicity) and ionic properties (e.g., hydrated radii and H-bonding). The results show that TSSE can remove >99.5% of selenium oxyanions and 96%-99.6% of mercury traces coexisting with sulfate (at a sixfold Se concentration) and chloride (at a 400-fold Se concentration) in a synthetic wastewater stream. Compared to diisopropylamine, decanoic acid is more effective in rejecting ions for all cases, ranging from a simple binary system to more complex multicomponent systems with highly varied ionic concentrations. Furthermore, the H-bonding interaction with water and the hydrated radii of the oxyanions (i.e., selenate vs. selenite) along with the hindrance effects caused by the molecular bulkiness and hydrophobicity (or lipophilicity) of the solvents play important roles in the favorable rejection of TSSE. This study shows that TSSE might provide a technological solution with a high deionization potential for the industry in complying with the Environmental Protection Agency regulations for discharge streams from coal-fired power facilities.
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Affiliation(s)
- Michael S. Meissner
- School of Chemical, Biological, and Materials Engineering, The University of Oklahoma, Norman, OK, United States
| | - Vy H. T. Nguyen
- School of Chemical, Biological, and Materials Engineering, The University of Oklahoma, Norman, OK, United States
| | - Imen Bousrih
- School of Chemical, Biological, and Materials Engineering, The University of Oklahoma, Norman, OK, United States
| | - Van T. C. Le
- School of Chemical, Biological, and Materials Engineering, The University of Oklahoma, Norman, OK, United States
| | - Alex Frickenstein
- Stephenson School of Biomedical Engineering, Norman, OK, United States
| | - Giang V. Le
- Central Institute for Natural Resources and Environmental Studies, Vietnam National University, Hanoi, Viet Nam
| | - Ngoc T. Bui
- School of Chemical, Biological, and Materials Engineering, The University of Oklahoma, Norman, OK, United States
- School of Civil Engineering and Environmental Science, The University of Oklahoma, Norman, OK, United States
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3
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Yu K, Lv Y, Jiang H, Li H, Shao P, Yang L, Shi H, Ren Z, Liu C, Luo X. Integrated effect of bulk cations on nano-confined reactivity of clay-intercalated subnanoscale zero-valent iron in water-tetrahydrofuran mixtures. JOURNAL OF HAZARDOUS MATERIALS 2023; 453:131347. [PMID: 37043853 DOI: 10.1016/j.jhazmat.2023.131347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 03/06/2023] [Accepted: 04/01/2023] [Indexed: 06/19/2023]
Abstract
Smectite clay-intercalated subnanoscale zero-valent iron (CSZVI) exhibits superior reactivity toward contaminants due to the small iron clusters (∼0.5 nm) under nano-confinement, which however is significantly influenced by the solution chemistry e.g., various cations, of polluted soil and water. This work was undertaken to elucidate the mechanisms of solution chemistry effects on dehalogenation ability of CSZVI in water-tetrahydrofuran solution using decabromodiphenyl ether as a model contaminant. By combined spectroscopic characterization and molecular dynamics simulation, it was revealed that bulk cations, i.e., Na+, K+, Mg2+ and Ca2+ collectively affected the interlayer distance, water content and Brønsted acidity of CSZVI and thus its degradation efficiency. Although causing inter-particle aggregation, Mg2+ induced optimal nano-confined interlayers at concentration of 20 mM, exhibiting a superior debromination efficiency with rate constant 9.84 times larger than that by the common nano-sized ZVI. Conversely, K+ rendered the interlayers less reactive, but protected CSZVI from corrosion loss with higher electron utilization efficiency, which was 1.7 times higher than CSZVI in presence of Mg2+. The findings provide new strategies to manipulate the reactivity of nano-confined CSZVI for effective wastewater and contaminated soil remediation.
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Affiliation(s)
- Kai Yu
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, PR China
| | - Yanni Lv
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, PR China
| | - Haowen Jiang
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, PR China
| | - Huimin Li
- Jiangxi Academy of Eco-Environmental Sciences and Planning, Nanchang 330006, PR China
| | - Penghui Shao
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, PR China
| | - Liming Yang
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, PR China
| | - Hui Shi
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, PR China
| | - Zhong Ren
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, PR China
| | - Cun Liu
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China.
| | - Xubiao Luo
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, PR China; College of Life Sciences, Jinggangshan University, Ji'an 343009, PR China.
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4
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Li Y, Mao X, Chen C, Zhang L, Liu W, Wang X, He L, Xu T. Highly Selective Reduction of Nitrate by Zero-Valent Aluminum (ZVAI) Ball-Milled Materials at Circumneutral pH: Important Role of Microgalvanic Cells for Depassivation of ZVAl and N 2-Selectivity. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:4568-4577. [PMID: 36848326 DOI: 10.1021/acs.est.2c09727] [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: 06/18/2023]
Abstract
The passivation of zero-valent aluminum (ZVAl) limits its application in environmental remediation. Herein, a ternary composite material Al-Fe-AC is synthesized via a ball-milling treatment on a mixture of Al0, Fe0, and activated carbon (AC) powders. The results show that the as-prepared micronsized Al-Fe-AC powder could achieve highly efficient nitrate removal and a nitrogen (N2)-selectivity of >75%. The mechanism study reveals that, in the initial stage, numerous Al//AC and Fe//AC microgalvanic cells in the Al-Fe-AC material could lead to a local alkaline environment in the vicinity of the AC cathodes. The local alkalinity depassivated the Al0 component and enabled its continuous dissolution in the subsequent second stage of reaction. The functioning of the AC cathode of the Al//AC microgalvanic cell is revealed as the primary reason accounting for the highly selective reduction of nitrate. The investigation on the mass ratio of raw materials manifested that an Al/Fe/AC mass ratio of 1:1:5 or 1:3:5 was preferable. The test in simulated groundwater suggested that the as-prepared Al-Fe-AC powder could be injected into aquifers to achieve a highly selective reduction of nitrate to nitrogen. This study provides a feasible method to develop high-performance ZVAl-based remedial materials that could work in a wider pH range.
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Affiliation(s)
- Yan Li
- School of Resources and Environmental Science, Wuhan University, Wuhan 430079, China
| | - Xuhui Mao
- School of Resources and Environmental Science, Wuhan University, Wuhan 430079, China
| | - Chaoqi Chen
- School of Resources and Environmental Science, Wuhan University, Wuhan 430079, China
| | - Lieyu Zhang
- Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Wenjie Liu
- School of Resources and Environmental Science, Wuhan University, Wuhan 430079, China
- Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Xu Wang
- School of Resources and Environmental Science, Wuhan University, Wuhan 430079, China
| | - Lang He
- Department of Earth and Environment, Franklin and Marshall College, Lancaster, Pennsylvania 17604-3003, United States
| | - Tao Xu
- School of Resources and Environmental Science, Wuhan University, Wuhan 430079, China
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5
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Sun F, Zhu Y, Liu X, Chi Z. Highly efficient removal of Se(IV) using reduced graphene oxide-supported nanoscale zero-valent iron (nZVI/rGO): selenium removal mechanism. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:27560-27569. [PMID: 36385336 DOI: 10.1007/s11356-022-24226-8] [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: 07/25/2022] [Accepted: 11/11/2022] [Indexed: 06/16/2023]
Abstract
Se(IV) removal using nanoscale zero-valent iron (nZVI) has been extensively studied. Still, the synergistic removal of Se(IV) by reduced graphene oxide-supported nanoscale zero-valent iron (nZVI/rGO) has not been reported. In this study, nZVI/rGO was successfully synthesized for Se(IV) removal from wastewater. The effects of different environmental conditions (load ratio, dosage, initial pH) on Se(IV) removal by nZVI/rGO were investigated. When the load ratio is 10%, the dosage is 0.3 g/L, the initial pH is 3, and the removal rate is 99%. The adsorption isotherm and kinetics accorded with the Langmuir isotherm and first-order kinetics models (R2 > 0.99). The fitted maximum adsorption capacity reached up to 173.53 mg/g. NZVI/rGo and Se(IV) is a spontaneous endothermic reaction (△G < 0, △H > 0) and is characterized by EDS, XRD, and XPS before and after the reaction, to further clarify the reaction mechanism. The XPS narrow spectrum analysis suggested that Se(IV) was reduced to elemental selenium (Se(0)), while the intermediate Fe(II) was oxidized to form hydroxide precipitation. Therefore, nZVI/rGO was favored for Se-contaminated wastewater remediation.
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Affiliation(s)
- Feiyang Sun
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, 130021, People's Republic of China
| | - Yuhuan Zhu
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, 130021, People's Republic of China
| | - Xinyang Liu
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, 130021, People's Republic of China
| | - Zifang Chi
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, 130021, People's Republic of China.
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6
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Yu H, Xuan C, Chen N, Zhang Q, Pan B. Reductive ethylenediamine group immobilized in hybrid Pd-based nanocomposite for efficiently sequestrating selenate. Sep Purif Technol 2023. [DOI: 10.1016/j.seppur.2023.123307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Chen J, Cheng X, Sheng G. Graphene oxide enhanced the reductive sequestration of UO22+, ReO4−, SeO42− and SeO32− by zero-valent iron: batch, column and mechanism investigations. J Radioanal Nucl Chem 2022. [DOI: 10.1007/s10967-022-08725-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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8
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Wu J, Huang G, Cao X, Dai Y, Miao L, Hou J, Xing B. Foliar Application of Reaction Products Derived from Selenite Removal by Iron Monosulfide for Brassica rapa ssp. Chinensis L. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:16281-16291. [PMID: 36282037 DOI: 10.1021/acs.est.2c05790] [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: 06/16/2023]
Abstract
The extensive application of FeS in environmental remediation requires the recovery and reuse of reaction products between FeS and pollutants. Therefore, foliar application of reaction products derived from selenite [Se(IV)] removal by FeS for pak choi was performed. The removal rate of Se(IV) by 100 mg/L FeS was 0.047 h-1. 93.2% of Se(IV) was reduced to Se(0), and FeS was correspondingly oxidized to goethite (78.9%), lepidocrocite (21.1%), and S(0) (91.5%) based on the analysis of X-ray absorption fine structure. The reaction products promoted the growth of pak choi in terms of fresh biomass, vitamin C, and protein, ascribed to the key roles of Fe and S in enhancing the electron transfer rate and light conversion rate. Furthermore, the application of reaction products decreased by 64% of disease incidence as compared with the pathogen Pseudomonas syringae pv. maculicola-infected control. The total Se content in plants increased to 576 μg/kg and was composed of 11.9% of SeMeCys, 29.8% of SeMet, and 58.3% of SeCys after exposure to reaction products, which is beneficial to the human dietary intake from pak choi. This study demonstrated that the reaction products between FeS and Se(IV) could be recovered and applied as a nano-enabled strategy to prevent crop insecurity.
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Affiliation(s)
- Jun Wu
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing210098, China
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts01003, United States
| | - Guoyong Huang
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou510006, China
| | - Xuesong Cao
- Institute of Environmental Processes and Pollution Control and School of Environment and Civil Engineering, Jiangnan University, Wuxi214122, China
| | - Yanhui Dai
- Institute of Coastal Environmental Pollution Control, and Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao266100, China
| | - Lingzhan Miao
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing210098, China
| | - Jun Hou
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing210098, China
| | - Baoshan Xing
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts01003, United States
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Wang A, Hou J, Feng Y, Wu J, Miao L. Removal of tetracycline by biochar-supported biogenetic sulfidated zero valent iron: Kinetics, pathways and mechanism. WATER RESEARCH 2022; 225:119168. [PMID: 36183543 DOI: 10.1016/j.watres.2022.119168] [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: 07/26/2022] [Revised: 09/13/2022] [Accepted: 09/23/2022] [Indexed: 06/16/2023]
Abstract
The application of zero-valent iron (ZVI) is limited due to passivation and agglomeration. Therefore, biochar loading (MB) and biogenetic sulfidation via sulfate-reducing bacteria (SRB) were used to improve the reactivity of ZVI (BS-ZVI@MB) towards tetracycline (TC) degradation. Biochar provided more attachment sites for ZVI and SRB, thus alleviating the agglomeration. Additionally, quinone groups on biochar enhanced the electrons transfer through the measurement of electron donating/accepting capacities, and biogenetic sulfidation could inhibit the surface passivation of ZVI. Fe(Ⅱ/Ⅲ) produced after the addition of BS-ZVI@MB could complex with the A ring in TC to form Fe(Ⅱ/Ⅲ)-TC, which brought the oxidation of TC by complexed Fe(Ⅲ). Reactive oxygen species (ROS)(primarily •OH) were generated during the oxidation of Fe(Ⅱ), so as to promote the TC degradation. Extracellular polymeric substances (EPS) secreted from SRB had a slight quenching effect on ROS. Meanwhile, EPS formed a protective layer with Fe(Ⅱ/Ⅲ) on BS-ZVI@MB, reducing its reactivity with TC. Overall, this study showed an efficient modification technology of ZVI by biogenetic sulfidation and biochar loading for TC degradation.
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Affiliation(s)
- Anqi Wang
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
| | - Jun Hou
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
| | - Yanfang Feng
- Key Laboratory of Agro-Environment in Downstream of Yangtze Plain, Ministry of Agriculture and Rural Affairs, Jiangsu Academy of Agricultural Sciences, Institute of Agricultural Resources and Environment, Nanjing 210014, China
| | - Jun Wu
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China.
| | - Lingzhan Miao
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
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Hou J, Wang A, Miao L, Wu J, Xing B. The role of nitrate in simultaneous removal of nitrate and trichloroethylene by sulfidated zero-valent Iron. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 829:154304. [PMID: 35304142 DOI: 10.1016/j.scitotenv.2022.154304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/23/2022] [Accepted: 02/28/2022] [Indexed: 06/14/2023]
Abstract
Sulfidated zero-valent iron (S-ZVI) is commonly used to degrade trichloroethylene (TCE). The reactivity of S-ZVI is related to not only the properties of S-ZVI but also the geochemical conditions in groundwater, such as coexisted NO3-. Therefore, the effect of NO3- on TCE degradation by S-ZVI and its mechanism were systematically studied. 95.17% of TCE was degraded to acetylene, dichloroethene, ethene, ethane and multi‑carbon products via β-elimination by fresh S-ZVI that contained 85.31% Fe0 and 14.69% FeS in the presence of NO3-, demonstrating that NO3- did not affect the degradation pathway of TCE. While high concentration of NO3- (> 10 mg/L) competed for electrons at the Fe/FeOx interface with degradation products, leading to a continuous rising of acetylene. Moreover, the rapid reduction of NO3- to NH4+ (89.79%) at the Fe0 interface contributed to the release of 5.08 mM Fe2+ from S-ZVI, which promoted the formation of Fe3O4 with excellent electron conduction properties on the surface of S-ZVI. Accordingly, NO3- improved the degradation and electron selectivity of TCE by 51.07% and 2.79 fold, respectively. This study demonstrated that S-ZVI could remediate the contamination of NO3- and TCE simultaneously and the presence of NO3- could effectively enhance the degradation of TCE in groundwater.
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Affiliation(s)
- Jun Hou
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
| | - Anqi Wang
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
| | - Lingzhan Miao
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
| | - Jun Wu
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China.
| | - Baoshan Xing
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, USA
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11
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Wang K, Martinez AF, Simonelli L, Madé B, Hénocq P, Ma B, Charlet L. Redox Interaction between Selenite and Mackinawite in Cement Pore Water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:5602-5610. [PMID: 35417136 DOI: 10.1021/acs.est.2c00901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
In cement-rich radioactive waste repositories, mackinawite (FeS) forms at the steel corrosion interface within reinforced concrete and potentially retards the transport of redox-sensitive radionuclides (e.g., 79Se) in porous cement media. Redox interactions between selenite and mackinawite under hyperalkaline conditions remain unclear and require further investigations. Here, using comprehensive characterization on both aqueous and solid speciation, we successfully monitored the whole interaction process between selenite and mackinawite under hyperalkaline conditions. The results show similar chemical environments for SeO32- and S2-/Sn2- at the mackinawite-water interface, verifying an immediate reduction. After 192 h of reaction, SeO32- was reduced to solid Se0 and SeS2 species, accompanied by the oxidation of S2-/Sn2- to S2O32- and Fe(II) to Fe(III) in mackinawite. Aqueous speciation results showed that ∼99% of aqueous selenium was present as Se4S nanoparticles due to the dissolution of Se from the solid. In parallel, ∼62% of S2-/Sn2- was released into the solution, with mackinawite transforming into magnetite, Fe(OH)3 and FeS2O3+ complexed to Cl- or OH- species, and magnetite subsequently dispersed in the solution. This study provides valuable data about the retardation mechanisms of redox-sensitive radionuclides by soluble iron sulfides, which is critical to advance our understanding of reactive concrete barriers used in nuclear waste disposal systems.
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Affiliation(s)
- Kaifeng Wang
- University of Grenoble Alpes and CNRS, ISTerre, BP 53, 38041 Grenoble Cedex 9, France
- Engineering Technology Center of Decommissioning and Remediation, China Institute of Atomic Energy, 102413 Beijing, China
| | | | - Laura Simonelli
- BL22 - CLAESS, ALBA Synchrotron Light Source, 08290 Barcelona, Spain
| | - Benoit Madé
- ANDRA, 1/7 rue Jean Monnet, Parc de la Croix Blanche, 92298 Chatenay-Malabry Cedex, France
| | - Pierre Hénocq
- ANDRA, 1/7 rue Jean Monnet, Parc de la Croix Blanche, 92298 Chatenay-Malabry Cedex, France
| | - Bin Ma
- University of Grenoble Alpes and CNRS, ISTerre, BP 53, 38041 Grenoble Cedex 9, France
- Laboratory for Waste Management, Paul Scherrer Institut (PSI), Forschungsstrasse 111, 5232 Villigen, Switzerland
| | - Laurent Charlet
- University of Grenoble Alpes and CNRS, ISTerre, BP 53, 38041 Grenoble Cedex 9, France
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12
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Holmes AB, Ngan A, Ye J, Gu F. Selective photocatalytic reduction of selenate over TiO 2 in the presence of nitrate and sulfate in mine-impacted water. CHEMOSPHERE 2022; 287:131951. [PMID: 34455127 DOI: 10.1016/j.chemosphere.2021.131951] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 08/04/2021] [Accepted: 08/18/2021] [Indexed: 06/13/2023]
Abstract
Selenium contamination is a critical global issue across numerous industries. Industrial waters such as mine-impacted water (MIW) can contain toxic levels of selenate, in addition to varying concentrations of many different dissolved species from the underlying strata, such as sulfate, carbonate, nitrate, organic matter, and many dissolved metals. The removal of selenate from MIW is desired, due to selenate's acute and chronic toxicity in aquatic ecosystems at elevated concentrations. However, due to the complexity of the water matrix and the presence of many other dissolved constituents, this is often very challenging. In this study, we present for the first time the reduction of selenate in a real industrial wastewater, namely MIW, and reveal a significant advantage of photocatalytic reduction; the ability to selectively reduce selenate from >500 μg L-1 to <2 μg L-1 in the presence of the more energetically favourable electron acceptor, nitrate (250× molar concentration of selenate) and high concentrations of sulfate (1,940× molar concentration of selenate). The presence and impacts of sulfate, chloride, carbonate, and nitrate on the competitive adsorption and reduction of selenate on TiO2 are thoroughly investigated for the first time, using formic acid as an electron hole scavenger. The electron transfer mechanism proposed follows TiO2 conduction band electrons are responsible for the reduction of selenate to elemental Se (Se0) and both carbon dioxide radicals (CO2·-) and Se conduction band electrons are responsible for the further reduction of Se0 to hydrogen selenide (H2Se).
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Affiliation(s)
- Andrew B Holmes
- Department of Chemical Engineering, University of Waterloo, 200 University Ave W., Waterloo, ON, N2L 3G1, Canada; Waterloo Institute of Nanotechnology, University of Waterloo, 200 University Ave W., Waterloo, ON, N2L 3G1, Canada
| | - Aldrich Ngan
- University of Toronto, Department of Chemical Engineering and Applied Chemistry, 200 College St, Toronto, ON, M5S 3E5, Canada
| | - Jane Ye
- Department of Environmental Sciences, University of Waterloo, 200 University Ave. W., Waterloo, ON, N2L 3G1, Canada
| | - Frank Gu
- Department of Chemical Engineering, University of Waterloo, 200 University Ave W., Waterloo, ON, N2L 3G1, Canada; Waterloo Institute of Nanotechnology, University of Waterloo, 200 University Ave W., Waterloo, ON, N2L 3G1, Canada; University of Toronto, Department of Chemical Engineering and Applied Chemistry, 200 College St, Toronto, ON, M5S 3E5, Canada.
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