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[Kinetics modeling and reaction mechanism of ferrate(VI) oxidation of triclosan].
Huan Jing Ke Xue. 2011 Sep; 32(9):2543-8.HJ

Abstract

Triclosan (TCS) is a broad-spectrum antibacterial agent widely used in many personal care products. We investigated oxidation of TCS by aqueous ferrate Fe(VI) to determine reaction kinetics, interpreted the reaction mechanism by a linear free-energy relationship, and evaluated the degradation efficiency. Second-order reaction kinetics was used to model Fe (VI) oxidation of TCS, with the apparent second-order rate constant (k(app)) being 531.9 L x (mol x s)(-1) at pH 8.5 and (24 +/- 1) degrees C. The half life (t1/2) is 25.8 s for an Fe(VI) concentration of 10 mg x L(-1). The rate constants of the reaction decrease with increasing pH values. These pH-dependent variations in k(app) could be distributed by considering species-specific reactions between Fe(VI) species and acid-base species of an ionizable TCS. Species-specific second-order reaction rate constants, k, were determined for reaction of HFeO4(-) with each of TCS's acid-base species. The value of k determined for neutral TCS was (4.1 +/- 3.5) x 10(2) L x (mol x s)(-1), while that measured for anionic TCS was (1.8 +/- 0.1) x 10(4) L x (mol x s)(-1). The reaction between HFeO4(-) and the dissociated TCS controls the overall reaction. A linear free-energy relationship illustrated the electrophilic oxidation mechanism. Fe (VI) reacts initially with TCS by electrophilic attack at the latter's phenol moiety. At a n[Fe(VI)]: n(TCS) > 7: 1, complete removal of TCS was achieved. And lower concentration of the humic acid could enhance the k(app) of Fe(VI) with TCS. In conclusion, Fe(VI) oxidation technology appears to be a promising tool for applications of WWTPs effluents and other decontamination processes.

Authors+Show Affiliations

State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China. ppyangbin@163.comNo affiliation info availableNo affiliation info available

Pub Type(s)

English Abstract
Journal Article
Research Support, Non-U.S. Gov't

Language

chi

PubMed ID

22165218

Citation

Yang, Bin, et al. "[Kinetics Modeling and Reaction Mechanism of ferrate(VI) Oxidation of Triclosan]." Huan Jing Ke Xue= Huanjing Kexue, vol. 32, no. 9, 2011, pp. 2543-8.
Yang B, Ying GG, Zhao JL. [Kinetics modeling and reaction mechanism of ferrate(VI) oxidation of triclosan]. Huan Jing Ke Xue. 2011;32(9):2543-8.
Yang, B., Ying, G. G., & Zhao, J. L. (2011). [Kinetics modeling and reaction mechanism of ferrate(VI) oxidation of triclosan]. Huan Jing Ke Xue= Huanjing Kexue, 32(9), 2543-8.
Yang B, Ying GG, Zhao JL. [Kinetics Modeling and Reaction Mechanism of ferrate(VI) Oxidation of Triclosan]. Huan Jing Ke Xue. 2011;32(9):2543-8. PubMed PMID: 22165218.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - [Kinetics modeling and reaction mechanism of ferrate(VI) oxidation of triclosan]. AU - Yang,Bin, AU - Ying,Guang-Guo, AU - Zhao,Jian-Liang, PY - 2011/12/15/entrez PY - 2011/12/15/pubmed PY - 2012/6/29/medline SP - 2543 EP - 8 JF - Huan jing ke xue= Huanjing kexue JO - Huan Jing Ke Xue VL - 32 IS - 9 N2 - Triclosan (TCS) is a broad-spectrum antibacterial agent widely used in many personal care products. We investigated oxidation of TCS by aqueous ferrate Fe(VI) to determine reaction kinetics, interpreted the reaction mechanism by a linear free-energy relationship, and evaluated the degradation efficiency. Second-order reaction kinetics was used to model Fe (VI) oxidation of TCS, with the apparent second-order rate constant (k(app)) being 531.9 L x (mol x s)(-1) at pH 8.5 and (24 +/- 1) degrees C. The half life (t1/2) is 25.8 s for an Fe(VI) concentration of 10 mg x L(-1). The rate constants of the reaction decrease with increasing pH values. These pH-dependent variations in k(app) could be distributed by considering species-specific reactions between Fe(VI) species and acid-base species of an ionizable TCS. Species-specific second-order reaction rate constants, k, were determined for reaction of HFeO4(-) with each of TCS's acid-base species. The value of k determined for neutral TCS was (4.1 +/- 3.5) x 10(2) L x (mol x s)(-1), while that measured for anionic TCS was (1.8 +/- 0.1) x 10(4) L x (mol x s)(-1). The reaction between HFeO4(-) and the dissociated TCS controls the overall reaction. A linear free-energy relationship illustrated the electrophilic oxidation mechanism. Fe (VI) reacts initially with TCS by electrophilic attack at the latter's phenol moiety. At a n[Fe(VI)]: n(TCS) > 7: 1, complete removal of TCS was achieved. And lower concentration of the humic acid could enhance the k(app) of Fe(VI) with TCS. In conclusion, Fe(VI) oxidation technology appears to be a promising tool for applications of WWTPs effluents and other decontamination processes. SN - 0250-3301 UR - https://www.unboundmedicine.com/medline/citation/22165218/[Kinetics_modeling_and_reaction_mechanism_of_ferrate_VI__oxidation_of_triclosan]_ L2 - https://medlineplus.gov/iron.html DB - PRIME DP - Unbound Medicine ER -