Superfast degradation of micropollutants in water by reactive species generated from the reaction between chlorine dioxide and sulfite

•CBZ was degraded by 80% within 10 s by the ClO2/sulfite process.•Experiments and kinetic model supported that SO4−·, ClO·, and Cl2O3 were the main reactive species.•DFT calculation and stopped-flow spectrometry confirmed the generation of Cl2O3.•pH 9.0 and ClO2/sulfite molar ratio of 1.0 were the optimal treatment conditions.•Formation of chloro-organic DBP, chlorite and chlorate were all below the drinking water standards.