Decomposition of chlorophenols in aqueous solution by UV/H2O2process

Publisher Website
Google Scholar
Abstract
The decomposition of 2,4‐dichlorophenol in aqueous solution by UV/H2O2 process was studied under various reaction conditions. Experimental results demonstrated that the hydroxyl free radical (OH∗) destruction would play an important role on decomposing chlorophenols for acidic solutions. For neutral and alkaline solutions, the direct photolysis would gradually be dominant on the decomposition of chlorophenols. The decomposition rate of 2,4‐dichlorophenol by UV/H2O2 process for acidic solutions increased with increasing H2O2 2,4‐dichlorophenol molar ratio until the ratio reached about 30 but the effect of H2O2 dosage was found to be less significant for alkaline solutions. Increased UV irradiation intensities would promote the decomposition rate of 2,4‐dichlorophenol and organic intermediates at both acidic and alkaline solutions. The mineralization efficiencies of 2,4‐dichlorophenol in aqueous solutions would be above 95% under adequate reaction conditions within five hours. The temporal behaviors of the decomposition of chlorophenols by UV/H2O2 process were well described by proposed two‐step kinetic models. The decomposition of chlorophenols in aqueous solution by UV/H2O2 process was found to start with the detachment of chlorine atom from the benzene ring and then to be mineralized by free radical attack.

This publication has 13 references indexed in Scilit: