Degradation of the antibacterial agents triclosan and chlorophene using hydrodechlorination by Al-based alloys

Abstract

Triclosan and chlorophene are chlorinated phenols used as antimicrobial agents. Both compounds are ordinarily detected in aquatic environments. The aim of this study is to prove the reactivity of three different metallic alloys used as common reductants such as Raney Al–Ni (50% Al–50% Ni), Devarda’s Al–Cu–Zn alloy (45% Al–50% Cu–5% Zn), and Arnd’s Cu–Mg alloy (60% Cu–40% Mg) for the hydrodechlorination of these agents in alkaline aqueous solution at ambient temperature and investigating such parameters as type and amount of reagents. The hydrodechlorination of triclosan was found to be completed when 5 molar equivalents of Al in the form of Raney Al–Ni alloy (0.27 g) and 20 equivalents of NaOH (0.8 g) per 1 mmol of triclosan were used and the reaction was performed at ambient temperature and pressure during 20 h of vigorous stirring. Chlorophene was completely dechlorinated using 2.5 equivalents of Al (0.14 g) and 10 equivalents of NaOH (0.4 g) per 1 mmol of chlorophene under the same conditions.