Photochemical oxidation of Cr(III) to Cr(VI) in the presence of Fe(III): Influence of Fe(III) concentration and UV wavelength.

Autor: Yen CC; Department of Soil and Environmental Sciences, National Chung Hsing University, Taichung 40227, Taiwan; Agricultural Chemistry Division, Taiwan Agricultural Research Institute, Ministry of Agriculture, Taichung 413008, Taiwan., Chen KY; Department of Agronomy, National Chiayi University, Chiayi 600355, Taiwan., Ahmed MMM; Department of Soil and Environmental Sciences, National Chung Hsing University, Taichung 40227, Taiwan; Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University, Taichung 40227, Taiwan., Syu CH; Agricultural Chemistry Division, Taiwan Agricultural Research Institute, Ministry of Agriculture, Taichung 413008, Taiwan., Liu YT; Department of Soil and Environmental Sciences, National Chung Hsing University, Taichung 40227, Taiwan; Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University, Taichung 40227, Taiwan., Hsieh YC; Office of the Texas State Chemist, Texas A&M AgriLife Research, Texas A&M University System, College Station, TX 77843, USA., Jien SH; Department of Soil and Environmental Sciences, National Chung Hsing University, Taichung 40227, Taiwan., Tzou YM; Department of Soil and Environmental Sciences, National Chung Hsing University, Taichung 40227, Taiwan; Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University, Taichung 40227, Taiwan. Electronic address: ymtzou@dragon.nchu.edu.tw.
Jazyk: angličtina
Zdroj: Journal of hazardous materials [J Hazard Mater] 2024 Dec 11; Vol. 485, pp. 136852. Date of Electronic Publication: 2024 Dec 11.
DOI: 10.1016/j.jhazmat.2024.136852
Abstrakt: The reduction of Cr(VI) to Cr(III) is key to lowering environmental toxicity and mobility, but the reverse process remains less understood. We investigated Cr(III) oxidation mechanisms across various pH levels and light wavelengths (185, 254, and 358 nm) in the presence of Fe(III). At pH 3.0 under 358 nm light, Cr(VI) production peaked at 11.65 μM, driven by photo-reactive Fe(OH)²⁺ producing •OH radicals. While Fe(III) generally promotes Cr(III) oxidation, concentrations above 0.5 mM inhibited the process. Oxidation was most intense under 185 nm light, generating up to 217 μM of Cr(VI), due to Fe(III) and water photolysis. At 254 and 358 nm, •OH was solely produced by Fe(III) photolysis, where •OH oxidized Fe(II), which then reduced Cr(VI), slowing Cr(III) oxidation. Short-wavelength, high-energy light significantly enhances Cr(III) oxidation. Under such UV exposure in the atmosphere, Cr(III)-containing aerosols and particles may undergo harmful transformations, potentially entering ecosystems via acidic deposition and posing health risks.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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