Abstract
The sonochemical degradation of pentachlorophenate (PCP) at 500 kHz in aqueous solutions saturated with air, oxygen or argon was investigated. The PCP degradation caused by ultrasonic irradiation involved fast cleavage of the carbon-chlorine bond releasing Cl(-). In solutions saturated with air or oxygen, PCP was mineralized to CO2. Nitrite and nitrate were formed in aerated solutions, and CO production was observed in solutions saturated with argon. Acute toxicity tests with the green algae Scendesmus subspicatus revealed that dissappearance of PCP resulted in a decrease of the toxicty of the treated solutions. According to the PCP degradation, the decrease of toxicity occurred more rapidely with argon than with air or oxygen. The results showed that ultrasonic irradiation may offer an approach to treat aqueous toxic wastes.