The influence of zero-valent iron on the photodegradation ozonation of di-2-ethylhexyl phthalate in aqueous solution

Abstract

In this study, the effect of nano zero-valent iron (NZVI) or Fe-0 on photolysis ozonation (UV/O-3) degradation of di-2-ethylhexyl phthalate (DEHP) was investigated. Applied pH, ozone dosage, NZVI dosage, reaction time, and initial concentration of DEHP were the parameters investigated under UVO3Fe0 process. The possible dominant mechanisms of DEHP degradation were also discussed. The degradation rate of DEHP gradually decreased with the increase in initial pH from 2 to 11 and increasing ozone dosage. When compared with other doses of NZVI, an NZVI dose of 200 mgL was found to be more effective. Ozone dosage had little influence on the removal of DEHP. The reaction time of 15 min and initial DEHP concentration of 5 mgL were optimum conditions in the combined process of UVO/Fe-3(0). A comparison of the reaction orders of kinetic studies showed that DEHP degradation is in accordance with pseudo-second-order reaction. At the optimum conditions, the reaction time of 15 min, the major by-products of the oxidation process were phthalic acid and ethyl 5-phenyl-2-penten-4-ynoate. The NZVI photodegradation ozonation technology was capable of efficiently removing DEHP from water solutions.