Degradation of P-nitrophenol Stimulated by Thermally Activated Persulfate:Effects of Temperature and Metal Ions

摘要

In this study,batch reactor experiments were performed to determine the degradation of PNP through thermally activated persulfate which was expected to produce highly reactive sulfate free radical(SO4-).Several factors including temperature(90°C,70°C,50°C),PH and metal ions which probably existed in groundwater such as Fe2+,Fe3+,Cu2+ etc on the degradation of PNP by the thermally activated persulfate were evaluated.The results showed that the elevation of temperature accelerated the removal of PNP in neutral solution adjusted by phosphate buffer (0.25M).Special attention was given to understand the effects of metal ions.A series of experiments with metal ions(Cu2+,Fe2+)at different temperature demonstrated that Fe2+ might behave as an intrinsic scavenger of sulfate radicals,accounting for the decrease in the rate of PNP oxidation underthermally activated system.However,the presence of Cu2+ in the aqueous solution promoted the degradation of PNP in some degree.Additionally,the precipitate formed in the course of reaction by the existence of metal ions might account for the decreasing in the removal of PNP[1].