Kinetics of Degradation of 4-Chlorophenol by Fenton Oxidation

In this paper, the degradation of 4-chlorophenol contaminated water by Fenton process was investigated. It was found that 4-chlorophenol could be removed efficiently by Fenton process, and rapidly be degraded into low molecular weight organics under an optimum concentration of hydrogen peroxide to ferrous sulfate ([H2O2]/[FeSO4]) molar ratio of 20:1. Based on the reaction characteristics of the contaminant oxidized by Fenton, degradation kinetics model of 4-chlorophenol was constructed, kinetics equation of 4-chlorophenol degradation was eventually obtained through experiments, which could be expressed as: dW/dt = kC(H2O2)(0.282) W-0.273, where: dW/dt is the reaction rate, k is the rate constant, CH2O2 is the concentration of H2O2, W is the concentration decrease of 4-chlorophenol. The results showed that the reaction rate could be significantly increased when the concentration of H2O2 increased, and temperature increased in favor of the degradation of 4-chlorophenol. The reaction mechanisms of degradation of 4-chlorophenol were analyzed based on the kinetics equation, and the entire degradation process could be divided into two stages of rapid reaction and slow reaction.