Facilitated ultrasonic irradiation in the degradation of diazinon insecticide

摘要

In this study, the degradation of diazinon insecticide was investigated using ultrasound facilitated by Fenton's and Fenton-like reagents under various experimental conditions. The effects of oxidant (persulphate ions, S 2 O 8 2 ? and hydrogen peroxide (H 2 O 2 )), transition metal (including Co 2+ , Ag + and Fe 2+ ), Fenton's reagent concentration and temperature on diazinon degradation were examined. A solution with an initial diazinon concentration of 50?mg?L ?1 was used in this study. Ultrasonic irradiation in combination with Fenton's and Fenton-like reagents not only effectively degraded diazinon but also rapidly reduced its toxicity. The optimal experimental conditions were determined as follows: 20?mg?L ?1 Fe 2+ , 150?mg?L ?1 H 2 O 2 , 25?°C and pH 3. After reacting for 60?min, the diazinon removal efficiency reached 98%, with a mineralization efficiency of 30%. Degradation occurred primarily via oxidation and resulted in the substitution of sulphur with oxygen in the diazinon PS bond.