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

Triclosan breakdown by Fenton-like oxidation

“…These differences can be attributed in part to the aforementioned chlorinated aromatic species (4,6-dichloro-1,2-benzenediol, 4,6-dichloro-1,3-benzenediol and 4-CC) which were detected in trace amounts (<1 lg/L). Although the occurrence of polymerization reactions has been commonly reported in Fenton oxidation of phenolic compounds [33,39,41,42], condensation byproducts have not been detected in this study. The chlorine balances matched always around 95%.…”

“…Yang et al [33] also achieved complete conversion of triclosan by ferrate oxidation but using an iron/triclosan molar ratio of 10, significantly higher than that used in the current work (0.5).…”

Ferrate(VI) oxidation of tetrabromobisphenol A in comparison with bisphenol A

“…3. Initially, Fe(VI) oxidizes the phenol moiety of TBBPA by one electron transfer generating a phenoxyl radical and Fe(V) as the first step (Rush et al, 1995;Huang et al, 2001;Li et al, 2008;Yang et al, 2011b). The phenoxy radical is stabilized by electron resonance within the phenol ring and forms radical R1, which supported by the calculation of charge distribution and spin densities via molecular modeling (Lin et al, 2009;Feng et al, 2013;Pang et al, 2014).…”

Removal of selected endocrine disrupting chemicals (EDCs) and pharmaceuticals and personal care products (PPCPs) during ferrate(VI) treatment of secondary wastewater effluents

“…Triclosan disappeared at the Fe(VI) exposure of 10.7 AE 2.8 mg L À1 min during Fe(VI) treatment (Table 1). Oxidation of triclosan by Fe(VI) involves scission of ether bond and phenoxy radical reaction (Yang et al, 2011b), yielding chlorophenol, 2-chlorobenzoquinone, 2,4-dichlorophenol and 2-chloro-5-(2,4-dichlorophenoxy)benzene-1,4-diol,5-chloro-3-(chlorohydroquinone)phenol,4,6-dichloro-2-(2,4-dichlorophenoxy)phenol and 3-chloro-2-(2,3-dichlorophenoxy)-6-(2,4-dichlorophenoxy) phenol (Yang et al, 2011b). Moreover, oxidation process of triclosan could result in a significant decrease in its algal toxicity (Yang et al, 2011b).…”

“…Oxidation of triclosan by Fe(VI) involves scission of ether bond and phenoxy radical reaction (Yang et al, 2011b), yielding chlorophenol, 2-chlorobenzoquinone, 2,4-dichlorophenol and 2-chloro-5-(2,4-dichlorophenoxy)benzene-1,4-diol,5-chloro-3-(chlorohydroquinone)phenol,4,6-dichloro-2-(2,4-dichlorophenoxy)phenol and 3-chloro-2-(2,3-dichlorophenoxy)-6-(2,4-dichlorophenoxy) phenol (Yang et al, 2011b). Moreover, oxidation process of triclosan could result in a significant decrease in its algal toxicity (Yang et al, 2011b). However, triclocarban did not react with Fe(VI) at pH 7.0 (Table 1),since its aromatic systems are deactivated (electron-depleted) by the electron-withdrawing chloro-substituents, and the amide-N is deactivated by the electron-withdrawing carbonyl group (Fig.…”