Removal of 2-chlorophenol from wastewater with the ultrasonic/Fenton process

Using the ultrasonic/Fenton oxidation to remove 2-chlorophenol from wastewater is presented this 354 paper. The combining ultrasonic and Fenton treatment enhances the decomposition efficiency of 2-chlorophennol and reduced the reaction time. In previous studies, the optimal conditions for carrying out the proposed ultrasonic/Fenton process are: pH maintained at 3, ionic strength of the solution adjusted at 0.1 N, ultrasonic amplitude maintained at 120 mm, and the reaction temperature controlled at 25 °C. In this study, the influent of Fenton reagent concentration and ratios of Fe²⁺ to H₂O₂ on the removal efficiency of 2-chlorophenol is investigated. Laboratory results indicate that the percentage of 2-chlorophenol decomposition increases for higher concentrations of Fenton reagent applied. If the concentration of H₂O₂ exceeds 50 mg/L, more than 100% of 2-chlorophenol is decomposed with more than 80% mineralized. The kinetics of the 2-chlorophenol decomposition rate can be fitted with a pseudo first-order kinetic equation, and the reaction rate constants are dependent upon the concentration of Fenton reagent applied. With increasing Fenton reagent concentrations, the observed reaction rate constants also increase. The oxidation/reduction potential (ORP) of the reaction is also monitored. Variations of the monitored ORP values are related to the oxidation of 2-chlorophenol.