Method for reducing chlorite as disinfection by-product of drinking water

The invention relates to a method for processing drinking water, in particular to a method for reducing chlorite as the disinfection by-product of drinking water. In the method, chlorine dioxide gas is first used to preoxidate raw water, lime is then added to regulate the pH value, coagulant is then added, coagulation, sedimentation and filtration are carried out to remove turbidity, and sodium hypochlorite solution is added for disinfection. Under the premise of ensuring that drinking water can meet the disinfection effect, the method which adopts the chlorine dioxide for preoxidation and the sodium hypochlorite for disinfection can greatly reduce the content of the chlorite as the disinfection by-product and ensure that the content of the chlorite can absolutely meet the requirement of the national standard on drinking water, thus greatly enhancing the safety of water quality.