Effects of inorganic anions on the photolysis of triclosan under UV irradiation

Abstract

Abstract Triclosan is a widely used antimicrobial agent and may pose health risks to many aquatic organisms. Photodegradation is an important transformation pathway for triclosan, but studies on the effects of inorganic anions on photodegradation of triclosan are limited. In the present study, the single and combined effects of NO3−, Cl− and HCO3− on the photolysis of triclosan in aqueous solutions under UV irradiation was evaluated. The results showed that photodegradation of triclosan was inhibited by NO3− and promoted by HCO3−, while no significant effect was observed with Cl−. When Cl− was added to NO3−, no effect was observed, but the addition of Cl− hindered the promotion effect of HCO3−. The coexistence of NO3−, Cl− and HCO3− inhibited the photolysis of triclosan. These results showed the complex effects of inorganic anions in the photolysis of triclosan and provide useful information for an accurate ecological risk assessment of triclosan in natural waters. It will also help to develop appropriate treatment ways of triclosan.