UVC-induced photodegradation of p-arsanilic acid assisted by humic substances

Quantum yields of indirect UVC photodegradation of p -arsanilic acid (a widely used phenylarsonic feed additive) caused by the photolysis of humic substances were measured. The acquired results demonstrate that the efficiency of such decomposition of p -arsanilic acid is comparable with that of its direct UVC photolysis due to the participation of active intermediates generated during the photolysis of humic substances. These results could be important for understanding the fate of p -arsanilic acid during an UVC disinfection of wastewaters containing natural humic substances.