Using Sonophotodegradation Technology for Removal of Organophosphorus Pesticides in Aqueous Solution

Abstract

Advanced oxidation processes (AOPs) such as sonolysis and sonophotolysis (sonophotodegradation) may be used to remove organic pollutants from an aqueous solution. Malathion and diazinon are both of highly effective organophosphorus pesticides that are used extensively in agriculture. The objective of this study was to investigate degradation of these pesticides (diazinon and malathion) using sonophotodegradation technology. The operational parameters used in the study to evaluate the processes were irradiation time, pH and initial concentrations of pesticide and the synergistic effect was also documented. Gas chromatography mass spectroscopy (GC-MS) was used to analyze the pesticides. Results showed that sonophotolysis was more effective than individual sonolysis and that degradation of both pesticides increased with a decrease in the initial concentration. The sonophotodegradation rate of the malathion pesticide was more than that of diazinon but the solonysis rate of both pesticides was about equal, hence photolysis was used effectively to remove the pesticides from water.