LAUSR

Abstract In this study, we assessed the reduction efficiency, kinetics and mechanism of a standard organophosphorus pesticide solution known as diazinone using microplasma. Atmospheric air was supplied as a carrier gas for the degradation of diazinone. The degradation kinetics of diazinone were analyzed by high performance liquid chromatography (HPLC) as a function of plasma-generated species that participated in the major degradation process. A freshly prepared 100 ppm solution of diazinone was treated for 300 s, and the treated samples were obtained at various time intervals, such as 10 s, 30 s, 60 s, 120 s, and 300 s. Degradation efficiency of the treated diazinone was measured using HPLC. Microplasma generated various species or radicals, such as dissolved ozone, oxides of nitrogen, OH radicals and hydrogen peroxide. The degradation efficiency varied with the presence or absence of different plasma-generated species. The roles of dissolved ozone and oxides of nitrogen on diazinone degradation were measured by a passive method. Oxides of nitrogen played a major role in diazinone degradation, and dissolved ozone could be positioned in the next place. HPLC data showed that diazinone degradation followed first-order reaction kinetics. The diazinone degradation mechanism by microplasma was suggested by analyzing the obtained data from liquid chromatography mass spectrometry (LC–MS).