Effect of pH, UV irradiation and hydrogen peroxide on the ozonation process of p-Chlorophenol

This study was designed to investigate the reaction mechanisms of oxidation of p-chlorophenol as one of the chlorinated phenolic compounds by ozone. I n this work, the influence of pH dependence, coupling with UV radiation and the addition of hydrogen peroxide were studied to improve the ozonation pr ocess of p-chlorophenol. Experimental results indicated that the molecular ozone is the predominant oxidant only at Tower pH. In Advanced Oxidation Pr ocesses (AOP's) such as ozone/higher pH, ozone/UV and ozone/hydrogen peroxi de, free radicals are considered to play an important role in the oxidation of p-chlorophenol. The results show that the rate of removal of p-chloroph enol depends on the applied process and decrease in the order O-3/UV > O-3/ H2O2 > O-3.