Microwave-enhanced Mn-Fenton process for the removal of BPA in water

Abstract

Microwave-enhanced Fenton oxidation process is a promising method to degrade Bisphenol A (BPA) in aqueous solution. In this study, Mn2+ ion was introduced into a microwave-enhanced Fenton system for removing BPA in wastewater. The results showed that the BPA removal rate in Microwave-enhanced Mn-Fenton (MW-Mn-Fenton) process was higher than that of in Fenton process or in other Fenton process with inclusion of metal under microwave irradiation. The effects of pH value, H2O2 dosage, Fe2+ ion dosage, Mn2+ ion dosage, initial concentration of BPA, microwave power and irradiation time on the degradation of BPA were investigated in detail. The optimum values of operating parameters were found at a pH value of 4.0, a H2O2 concentration of 34.0mg/L, a Fe2+ ion concentration of 2.1mg/L, a Mn2+ ion concentration of 2.7mg/L, a microwave power of 300.0W after 6.0min of irradiation when the initial concentration of BPA was 100.0mg/L. Under the optimal conditions, the removal efficiency of BPA and Total Organic Carbon (TOC) reached 99.7% and 53.1%, respectively. The BPA can be degraded completely at low initial concentration. The degradation efficiency for the BPA aqueous solution decreased gradually with increasing pH value was from 2.0 to 8.0. Less iron sludge was produced in short time and greater reagent utilization efficiency was achieved in MW-Mn-Fenton process in comparison with normal Fenton process. This study facilitates further research for practical application of the Fenton process in water treatment.