Effects of pipe material on chlorite formation in combined disinfection of chlorine and chlorine dioxide

To know the effects of combined disinfection on DBPs and enhance water quality safety, static pipe reactors were used and three kinds of commonly used pipe materials were selected to investigate the effects of pipe materials on chlorite formation in combined disinfection of chlorine and chlorine dioxide. Results indicated that the chlorite levels were the highest in PVC pipe and lower in metal pipes for both of the two kinds of combined disinfection. The difference between the two ways was that in the way of adding chlorine and chlorine dioxide together, chlorite levels in the ductile iron pipe increased with the increase of chlorine and decrease of chlorine dioxide in the mixed disinfectant. While, for the way of adding chlorine first and then adding chlorine dioxide, the chlorite levels were higher in ductile iron pipe than that in stainless steel from the beginning to the end.