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Oxidation of triclosan by ferrate: Reaction kinetics, products identification and toxicity evaluation

Journal Article


Abstract


  • The oxidation of triclosan by commercial grade aqueous ferrate (Fe(VI)) was investigated and the reaction kinetics as a function of pH (7.0–10.0) were experimentally determined. Intermediate products of the oxidation process were characterized using both GC–MS and RRLC–MS/MS techniques. Changes in toxicity during the oxidation process of triclosan using Fe(VI) were investigated using Pseudokirchneriella subcapitata growth inhibition tests. The results show that triclosan reacted rapidly with Fe(VI), with the apparent second-order rate constant, kapp, being 754.7 M-1 s-1 at pH 7. At a stoichiometric ratio of 10:1 (Fe(VI):triclosan), complete removal of triclosan was achieved. Species-specific rate constants, k, were determined for reaction of Fe(VI) with both the protonated and deprotonated triclosan species. The value of k determined for neutral triclosan was 6.7(±1.9) × 102 M-1 s-1, while that measured for anionic triclosan was 7.6(±0.6) × 103 M-1 s-1. The proposed mechanism for the oxidation of triclosan by the Fe(VI) involves the scission of ether bond and phenoxy radical addition reaction. Coupling reaction may also occur during Fe(VI) degradation of triclosan. Overall, the degradation processes of triclosan resulted in a significant decrease in algal toxicity. The toxicity tests showed that Fe(VI) itself dosed in the reaction did not inhibit green algae growth.

Authors


  •   Yang, Bin (external author)
  •   Ying, Guang-Guo (external author)
  •   Zhao, Jian-Liang (external author)
  •   Zhang, Li-Juan (external author)
  •   Fang, Yi-Xiang (external author)
  •   Nghiem, Long D.

Publication Date


  • 2011

Citation


  • Yang, B., Ying, G., Zhao, J., Zhang, L., Fang, Y. & Nghiem, L. Duc. (2011). Oxidation of triclosan by ferrate: Reaction kinetics, products identification and toxicity evaluation. Journal of Hazardous Materials, 186 (1), 227-235.

Scopus Eid


  • 2-s2.0-79551542373

Ro Metadata Url


  • http://ro.uow.edu.au/engpapers/5546

Has Global Citation Frequency


Number Of Pages


  • 8

Start Page


  • 227

End Page


  • 235

Volume


  • 186

Issue


  • 1

Place Of Publication


  • Netherlands

Abstract


  • The oxidation of triclosan by commercial grade aqueous ferrate (Fe(VI)) was investigated and the reaction kinetics as a function of pH (7.0–10.0) were experimentally determined. Intermediate products of the oxidation process were characterized using both GC–MS and RRLC–MS/MS techniques. Changes in toxicity during the oxidation process of triclosan using Fe(VI) were investigated using Pseudokirchneriella subcapitata growth inhibition tests. The results show that triclosan reacted rapidly with Fe(VI), with the apparent second-order rate constant, kapp, being 754.7 M-1 s-1 at pH 7. At a stoichiometric ratio of 10:1 (Fe(VI):triclosan), complete removal of triclosan was achieved. Species-specific rate constants, k, were determined for reaction of Fe(VI) with both the protonated and deprotonated triclosan species. The value of k determined for neutral triclosan was 6.7(±1.9) × 102 M-1 s-1, while that measured for anionic triclosan was 7.6(±0.6) × 103 M-1 s-1. The proposed mechanism for the oxidation of triclosan by the Fe(VI) involves the scission of ether bond and phenoxy radical addition reaction. Coupling reaction may also occur during Fe(VI) degradation of triclosan. Overall, the degradation processes of triclosan resulted in a significant decrease in algal toxicity. The toxicity tests showed that Fe(VI) itself dosed in the reaction did not inhibit green algae growth.

Authors


  •   Yang, Bin (external author)
  •   Ying, Guang-Guo (external author)
  •   Zhao, Jian-Liang (external author)
  •   Zhang, Li-Juan (external author)
  •   Fang, Yi-Xiang (external author)
  •   Nghiem, Long D.

Publication Date


  • 2011

Citation


  • Yang, B., Ying, G., Zhao, J., Zhang, L., Fang, Y. & Nghiem, L. Duc. (2011). Oxidation of triclosan by ferrate: Reaction kinetics, products identification and toxicity evaluation. Journal of Hazardous Materials, 186 (1), 227-235.

Scopus Eid


  • 2-s2.0-79551542373

Ro Metadata Url


  • http://ro.uow.edu.au/engpapers/5546

Has Global Citation Frequency


Number Of Pages


  • 8

Start Page


  • 227

End Page


  • 235

Volume


  • 186

Issue


  • 1

Place Of Publication


  • Netherlands