Degradation of fungicide carbendazim in aqueous solution by sonolytic ozonation

Carbendazim is a fungicide with a high level of consumption worldwide. As an estrogenic disrupter, carbendazim is hazardous to humans and animals. In this study, we investigated the potential degradation of carbendazim in aqueous solution by ozonation (O₃) combined with sonolysis (ultrasound, US) in laboratory-scale experiments. The results showed that degradation of this fungicide could be conducted in the processes of US or O₃ only, and a combination of US/O₃, but the combined US/O₃ process provided much better outcome. Under the experimental conditions, the rate of carbendazim degradation could be described by pseudo-first-order kinetic models. Both O₃ dose and US energy density had a positive effect on the degradation of carbendazim in the tested ranges. The maximum degradation was observed at pH 9.0 whilst temperature had a minor effect within 25-45°C. As the initial concentration of carbendazim decreased, the degradation rate increased. Half-life degradation period was mostly about several minutes in the process of US/O₃ within the carbendazim concentration range studied.