[Rapid elimination of surface organophosphorous pollutants using hydroxyl radical]

According to the frequency of contamination accident for organic compounds in recent years, two kinds of organophosphorus pesticides dichlorvos and omethoate, as the simulated organic pollutants, were rapidly eliminated using spraying hydroxyl radical produced by strong electric-field ionization discharge method on an aluminium flat plate about 160 cm2. The high concentration aqueous *OH solution was produced from H2O(gas) and O2 with plasma reaction. In a condition, where pH is 6 and the initial densities of dichlorvos and omethoate on the simulation plane are both 60 microg x cm(-2), when the spray density of *OH reaches 3.9 microg x cm-2, removal efficiencies of dichlorvos and omethoate are 90%, and mineralization rates are 64% and 72%, respectively. The effect of pH for removal efficiency was also investigated. The results found that the removal efficiency of organophosphorus pollutants first decreased slowly and then increased fast with the increase of pH from 2 to 12 and the lowest removal rate appeared when pH close to neutral. The degradation rates of dichlorvos and omethoate both ascend by 21% and 26% respectively with pH 12 than that of pH 6. Four factors and three levels orthogonal test indicated that the degradation by *OH played a major role at the surface oxidation removal rapid of organophosphorus pollutants in a short period of time.