Ferrate(VI) oxidation of polychlorinated diphenyl sulfides: Kinetics, degradation, and oxidized products

Jing Chen; Xinxin Xu; Xiaolan Zeng; Mingbao Feng; Ruijuan Qu; Zunyao Wang; Nasri Nesnas; Virender K Sharma

doi:10.1016/j.watres.2018.06.023

Ferrate(VI) oxidation of polychlorinated diphenyl sulfides: Kinetics, degradation, and oxidized products

Water Res. 2018 Oct 15:143:1-9. doi: 10.1016/j.watres.2018.06.023. Epub 2018 Jun 13.

Authors

Jing Chen¹, Xinxin Xu¹, Xiaolan Zeng¹, Mingbao Feng², Ruijuan Qu³, Zunyao Wang¹, Nasri Nesnas⁴, Virender K Sharma⁵

Affiliations

¹ State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu, 210023, PR China.
² Program for the Environment and Sustainability, Department of Environmental and Occupational Health, School of Public Health, Texas A&M University, College Station, TX, 77843, USA.
³ State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu, 210023, PR China. Electronic address: quruijuan0404@nju.edu.cn.
⁴ Department of Chemistry, Florida Institute of Technology, 150 W University Blvd, Melbourne, FL, 32901, USA.
⁵ Program for the Environment and Sustainability, Department of Environmental and Occupational Health, School of Public Health, Texas A&M University, College Station, TX, 77843, USA. Electronic address: vsharma@sph.tamhsc.edu.

PMID: 29929163
DOI: 10.1016/j.watres.2018.06.023

Abstract

This paper presents oxidation of polychlorinated diphenyl sulfides (PCDPSs), dioxin-like compounds, by ferrate(VI) (Fe^VIO₄^2-, Fe(VI)). Kinetics of the reactions of Fe(VI) with seventeen PCDPSs, differ in number and positions of chlorine atoms (from 2 to 7), were investigated at pH 8.0. The second-order rate constants (k, M^-1 s^-1) of the reactions varied with the numbers and positions of chlorine atoms and appeared to be related with standard Gibbs free energy of formation (Δ_fG⁰) of PCDPSs. Degradation experiments in the presence of ions and humic acid demonstrated complete removal of PeCDPS by Fe(VI) in minutes. Pathways of the reaction were investigated by identifying oxidized products (OPs) of the reaction between Fe(VI) and 2,2',3',4,5-pentachlorodiphenyl sulfide (PeCDPS) at pH 8.0. Pathways of oxidation involved major pathway of attack on sulfur(II) by Fe(VI) in steps to yield sulfoxide type products, and subsequent breakage of C-S bond with the formation of sulfonic acid-containing trichloro compound. Minor pathways were hydroxylation of benzene ring and substitution of chlorine atom with hydroxyl group. Estimation of toxicity of OPs of the oxidation of PeCDPS by Fe(VI) suggested the decreased toxicity from the parent contaminant.

Keywords: Dioxin-like compounds; Estimated toxicity; Ferrate; Reaction pathways; Water constituents.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Aquatic Organisms / drug effects
Chromatography, Liquid
Ecotoxicology / methods
Humic Substances
Hydrogen-Ion Concentration
Iron / chemistry*
Kinetics
Mass Spectrometry
Oxidation-Reduction
Polychlorinated Biphenyls / chemistry*
Polychlorinated Biphenyls / toxicity
Spectrometry, Mass, Electrospray Ionization
Sulfides / chemistry*
Water Pollutants, Chemical / chemistry*
Water Pollutants, Chemical / toxicity

Substances

Humic Substances
Sulfides
Water Pollutants, Chemical
ferrate ion
diphenyl sulfide
Polychlorinated Biphenyls
Iron