Removal of IBMP using ozonation: role of ozone and hydroxyl radical

Abstract

AbstractOzonation of a representative taste and odor compound, 2-Isobutyl-3-methoxy pyrazine (IBMP), in drinking water was systematically investigated in this study. Batch experiments were conducted to evaluate the influencing factors including initial IBMP concentration, O3 addition rate, initial pH, H2O2 dosage, and different water qualities on the degradation of IBMP in the ozonation process. Results showed that the degradation of IBMP followed pseudo-first order kinetics. The degradation rate constants increased with the increasing O3 addition rate and initial pH value, whereas it decreased with the increasing initial IBMP concentration. Degradation of IBMP is mainly dominated by direct ozone oxidation at low pH, while the free radical oxidation may become dominant at high pH levels. Moreover, appropriate H2O2 dosage can greatly increase the IBMP degradation rates, but large excess H2O2 would act as an scavenger and inhibit the degradation. In addition, lower degradation rate was observed in raw water...