Enhanced oxidation · Enhanced micropollutant oxidation by permanganate- and manganese(II)-based processes in presence of dissolved organic matter and hydrogen peroxide

Micropollutants are a serious problem for drinking water and wastewater due to their adverse human and ecosystem’s health effects. In Europe, their abatement often involves ozonation with O3 and hydroxyl radical abating a wide spectrum of micropollutants. However, the potential formation of carcinogenic disinfection byproducts such as bromate and N-nitrosamines threatens the safety of drinking water/wastewater. Permanganate (Mn(VII)) is a selective oxidant that is widely applied in pre-oxidation steps in water treatment to remove Mn(II), Fe(II) and taste/odor and produces little disinfection byproducts. It has a high reactivity with phenolic compounds. The applicant found that the phenolic moieties in dissolved organic matter (DOM) produce secondary oxidants with permanganate to enhance micropollutant abatement. Furthermore, the applicant discovered that hydrogen peroxide (H2O2) can not only produce secondary oxidants including Mn(VI) and superoxide radical when reacting with permanganate to enhance micropollutant abatement, but also reduce permanganate to MnO2 that can be removed during coagulation and filtration. Moreover, superoxide and hydroxyl radical were observed to be produced by the Mn(II)-H2O2 reaction. As another matrix, bicarbonate (HCO3–/CO32–) facilitated the Mn(II)-H2O2 reaction to achieve a fast micropollutant abatement, which shows a good application potential for reduced water sources by dosing H2O2. This project aims to investigate the kinetics and mechanisms of the enhancing role of DOM, its surrogate compounds and H2O2 on MnO4–-induced micropollutant abatement. Furthermore, the effectiveness of Mn(II)/H2O2(/HCO3–/CO32–) for micropollutant abatement will be investigated. Both processes will provide alternative enhanced oxidative treatment to abate micropollutants in water and wastewater.