.2,4-d Ozone, Ozone / Hydrogen Peroxide Treatment Of The Wastewater

An investigation of kinetics and reaction mechanisms of 2,4-Dichlorophenoxyacetic acid (2,4-D) degraded by O3 and O3/H2O2 system was performed, and gists for treating with wastewater containing 2,4-D were afforded.During ozonation of 2,4-D, the remove rate of 2,4-D increased with increasing pH of solution, increasing temperature and enhancing gas flow rate, but the degree of enhancing descended with high temperature. The remove rate of 2,4-D decreased with increasing concentration of 2,4-D. The intermediates were identified by GC-MS, HPLC and IC. The 2,4-D decay followed a pseudo first-order reaction. A possible reaction pathway for 2,4-D degradation by O3 involving all intermediates detected was proposed.During catalytic ozonation of 2,4-D with H2O2, the remove rate of 2,4-D decreased with increasing pH of solution, increasing temperature, enhancing gas flow rate and increasing dosage of H2O2, but the degree of enhancing descended with high temperature. The remove rate of 2,4-D decreased with increasing concentration of 2,4-D. The methods of adding H2O2 had scarcely any influence on the remove rate of 2,4-D. The intermediates were identified by GC-MS, HPLC and IC. A possible reaction pathway for 2,4-D degradation by H2O2 involving all intermediates detected was proposed.Comparing with ozonation of 2,4-D, catalytic ozonation of 2,4-D with H2O2 showed higher TOC and COD remove rate owing to the hydroxyl radical produced by catalytic ozonation with H2O2, and was more economical.