Study of Removal Effect and Mutagenicity on Cyclops with Oxidants

Cyclops of zooplankton propagated excessively in eutrophic water body and it couldn´t be effectively inactivated by the conventional disinfection process. In this paper, a study of removal effect on Cyclops with oxidants in a drinking waterworks in China was conducted. Among five oxidants, chlorine dioxide was more effective against Cyclops and the potassium permanganate was the weakest with the same conditions. The full-scale results showed that Cyclops could be effectively removed from water by 1.0 mg/L chlorine dioxide preoxidation cooperating with the conventional clarification process. The chlorite, by-product of prechlorine dioxide, was about at 0.45 mg/L after filtration, which is lower than the critical value of the USEPA. The Ames test further showed that the mutagenicity in the treated water by chlorine dioxide preoxidation were obviously less than that of prechlorination.