Degradation of organophosphorus pesticide induced by oxygen plasma: Effects of operating parameters and reaction mechanisms

The degradation effectiveness and degradation mechanism of representative organophosphorus (OP) pesticide during oxygen plasma treatment have been studied. The identification and quantitative determination of OP pesticide, the degradation mechanisms for OP pesticide destruction, its destruction intermediates, and by-products were performed using gas chromatography/mass spectrometry (GC/MS). Plausible mechanisms of the degradation are discussed. Experimental results indicate that oxygen plasma treatment has noticeable effects on OP pesticide with satisfactory degradation efficiency, which mainly depends on related operating parameters including plasma treatment time, discharge power, distance from the center of the induction coil, and concentrations of OP pesticide. It was found that OP pesticide was degraded into less-toxic compounds, and free radical reaction and addition reaction were to be the dominated the degradation mechanisms for OP pesticides treated by oxygen plasma. Therefore, our results suggest that oxygen plasma is suitable for degradation of OP pesticide.