Electrochemical Degradation of Triclosan at a Ti/SnO2- Sb/Ce-PbO2 Anode

Electrochemical degradation of an emerging contaminant, triclosan (5-chloro-2-(2,4dichlorophenoxy) phenol) by a Ti/ SnO2-Sb/Ce-PbO2 anode was investigated. The degradation efficiency attained > 99.9% during 5 min of electrolysis at all influential factors, i. e., applied current density (2-10 mA/cm2), pH 3-11, inter-electrode distance (1-4 cm), initial concentration (0.5-5 mg/L triclosan) and supporting electrolyte (10 mmol/L NaCl). Total organic carbon removal ratio achieved 79.7% at the optimal conditions after 2 min of electrolysis. The electrochemical degradation of triclosan followed pseudo-first-order kinetics. The intermediate products namely 2,4-dichlorophenol, 5-chloro-3-(chlorohydroquinone) phenol and 2-chloro-5-(2,4-dichlorophenoxy) benzene-1,4-diol were prominently detected using liquid chromatography-tandem mass spectrometry. A degradation mechanism of triclosan at the Ti/SnO2-Sb/Ce-PbO2 anode was proposed based on the intermediates. The energy consumption of triclosan (4 mg/L) degradation at different electrode distances (1-4 cm) was 0.466-2.225 kWhm(-3). The Ti/SnO2-Sb/Ce-PbO2 anodes can be employed preliminary for rapid degradation of triclosan in wastewater.