Degradation of 4-chlorophenol by microwave-enhanced advanced oxidation processes: Kinetics and influential process parameters

Abstract

In this study, the degradation of 4-chlorophenol (4-CP) is investigated by using a combination of microwave (MW) irradiation and hydrogen peroxide as oxidant (the MW-H2O2-process). The influence of the critical parameters on the efficiency of the process is examined by applying Partial Least Square Regression (PLS) on a Design of Experiments (DOE). Also, a kinetic evaluation of the process is carried out. Results showed that the MW-H2O2-process is effective in the degradation of 4-CP. The most influential parameter of the MW-H2O2-process is the reaction temperature. Besides this parameter, the reaction time, initial 4-CP concentration, and initial hydrogen peroxide concentration have a (minor) influence on the 4-CP degradation. A maximum degradation efficiency within the levels of the DOE (remaining percentage of 4-CP of 34%) was achieved with an initial 4-CP concentration of 1000 mg/L, an initial H2O2 concentration of 11 g/L, reaction temperature of 180 °C, and reaction time of 20 min. The process follows pseudo first order reaction kinetics.