▎ 摘 要
Photocatalytic degradation of pirimiphos-methyl using silica-functionalized graphene oxide (GO)/ZnO incorporated with fiberglass (silica-GO/ZnO) was evaluated. The effect of different variables including the initial concentration of pirimiphos-methyl, temperature, contact time, and hydrogen peroxide concentration was tested on the photocatalytic degradation. Moreover, the effect of co-existing organic compounds (folic acid, citric acid, oxalate, phenol, and ethylenediaminetetraacetic acid) and different purging gases (oxygen and nitrogen) was explored. The maximum removal efficiency was achieved at a neutral medium, in other words at acidic and alkaline conditions the catalyst corrosion occurred which resulted in a decrease in efficiency. By increasing the temperature, the photocatalytic removal efficiency using silica-GO/ZnO increased, because of the catalyst expansion and therefore, greater availability of functional groups. With an increase in the concentration of pollutant from 5 to 60 mg/L, the k(obs) values decreased from 0.050 to 0.005, while the electrical energy per order (E-E0) increased from 95.81 to 923.12 kWh/m(3). The removal efficiency of pirimiphos-methyl in the absence of hydrogen peroxide under the optimal conditions of other factors was obtained by approximate to 98%. However, as the concentration of hydrogen peroxide increased from 3 to 45 mM, the removal efficiency decreased from 86.74% to 81.61%, respectively. The presence of organic compounds acted as a scavenger and resulted in reduced removal efficiency. The findings of this study also suggested that purging of oxygen gas provided greater photocatalytic activity compared to nitrogen and ambient air for the degradation of the target contaminant.