A Study On The Characteristics Of Ozonation And Catalytic Ozonation Of Pentachlorophenol

Pentachlorophenol(PCP)is widely used as fungicide and herbicide,which has been provened to have endocrine interference.The purpose of this research is to study the characteristics of ozonation and catalytic ozonation of PCP in water.The kinetics of ozonation is also preliminarily studied.The result shows that,the pH value and the initial concentration of PCP all have a great effect of degradation of PCP.The remove rate of PCP increased with increasing pH value of solution,but decreased with increasing the initial concentration of PCP.The characteristics of catalytic and non-catalytic system were discussed in this paper.The result showed that catalytic ozonation system was about the same as the ozonation system.But the efficency of catalytic ozonation was faster than the ozonation process.In this paper,HPLC method was used to determine the hydroxyl radicals generated in two systems.The hydroxyl radicals generated in catalytic ozonation system is more than ozonation system.The degredation pathways of PCP in ozonation and catalytic ozonation were proposed with UV,IC and GC/MS.In the degradation process of PCP,the Cl^-were first released.The intermediates of PCP were phenol,toluene,styrene and others. through hydroxylation dechlorination.Then they turned into ester,acid,alcoholic aldehyde ect.,which turned into CO₂ at last.In the process of catalytic ozonation,the intermediates probably included complex compound,which promoted the reaction rate of catalytic ozonation faster than the ozonation.The kinetics of PCP was studied in this paper and the PCP decay followed a pseudo first-order reaction.