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Sun H, Wang J, Jiang Y, Shen W, Jia F, Wang S, Liao X, Zhang L. Rapid Aerobic Inactivation and Facile Removal of Escherichia coli with Amorphous Zero-Valent Iron Microspheres: Indispensable Roles of Reactive Oxygen Species and Iron Corrosion Products. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:3707-3717. [PMID: 30817131 DOI: 10.1021/acs.est.8b06499] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Zero valent iron (ZVI) is recently regarded as a promising alternative for water disinfection, but still suffers from low efficiency. Herein we demonstrate that amorphous zerovalent iron microspheres (A-mZVI) exhibit both higher inactivation rate and physical removal efficiency for the disinfection of Escherichia coli than conventional crystalline nanoscale ZVI (C-nZVI) under aerobic condition. The enhanced E. coli inactivation performance of A-mZVI was mainly attributed to more reactive oxygen species (ROSs), especially free •OH, generated by the accelerated iron dissolution and molecular oxygen activation in bulk solution. In contrast, C-nZVI preferred to produce surface bound •OH, and its bactericidal ability was thus hampered by the limited physical contact between C-nZVI and E. coli. More importantly, hydrolysis of dissolved iron released from A-mZVI produced plenty of loose FeOOH to wrap E. coli, increasing the dysfunction of E. coli membrane. Meanwhile, this hydrolysis process lowered the stability of E. coli colloid and caused its rapid coagulation and sedimentation, favoring its physical removal. These findings clarify the indispensable roles of ROSs and iron corrosion products during the ZVI disinfection, and also provide a promising disinfection material for water treatment.
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Affiliation(s)
- Hongwei Sun
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, College of Chemistry , Central China Normal University , Wuhan 430079 , P. R. China
| | - Jian Wang
- Hubei Key Lab of Genetic Regulation and Integrative Biology, School of Life Sciences , Central China Normal University , Wuhan 430079 , P. R. China
| | - Yao Jiang
- Hubei Key Lab of Genetic Regulation and Integrative Biology, School of Life Sciences , Central China Normal University , Wuhan 430079 , P. R. China
| | - Wenjuan Shen
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, College of Chemistry , Central China Normal University , Wuhan 430079 , P. R. China
| | - Falong Jia
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, College of Chemistry , Central China Normal University , Wuhan 430079 , P. R. China
| | - Shaohui Wang
- Hubei Key Lab of Genetic Regulation and Integrative Biology, School of Life Sciences , Central China Normal University , Wuhan 430079 , P. R. China
| | - Xiaomei Liao
- Hubei Key Lab of Genetic Regulation and Integrative Biology, School of Life Sciences , Central China Normal University , Wuhan 430079 , P. R. China
| | - Lizhi Zhang
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, College of Chemistry , Central China Normal University , Wuhan 430079 , P. R. China
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