Sonochemical kinetic model of diazinon and malathion pesticides degradation in aqueous solution

In this work, elimination two types of organophosphorus pesticides, diazinon and malathion spiked in aqueous solution by ultrasonic irradiation was investigated. Six different initial concentrations of diazinon and malathion (100, 300, 500, 200, 400, and 600 μg/L respectively) at different pH (3, 7, 9) and time (30, 45, 60, 90, 105 min) were investigated. Results showed that diazinon and malathion could be effectively and rapidly degraded by ultrasonic irradiation, and kinetics of both pesticides was strongly influenced by time, initial concentration and pH value. The results showed optimum condition degradation achieved at pH 3 and 9 for diazinon and malathion, respectively. Kinetic modeling applied for the obtained results showed that the degradation of diazinon and malathion by ultrasound followed first – order and second – order model.