The Research on Removing Cyclops of Zooplankton in Raw Water by Purification Process Combined with Pre-Oxidations

Cyclops of zooplankton threatens the drinking-water security because of the massive propagation in the polluted water resource and the ineffective treatment by conventional purification technology. The inactivation effects on Cyclops in the raw water of the pre-oxidants, such as chloramines, chlorine, potassium permanganate composite (PPC) and ozone, were discussed. And the synergic removal effects on Cyclops which pre-oxidation follows by purification process is investigated systemically with two pilot test equipments. The results show that, the removal effects on Cyclops depend on the reasonable coordination between pre-oxidation and the following water clarification process, the higher removal effects don´t necessarily result from the higher inactivation effects. The most important treatment unit on removing Cyclops is the filter tank, and the removal effect of the individual filter unit can be about 50%. The removal effect of the air-floating unit may be about 20%, which is closely related to the size and the activity of Cyclops. Cooperating with pre-oxidation stage and air-floating, the removal effect of above 80% can be obtained after filtration, and about 90% of Cyclops can be removed after the advanced treatment. The 100% of removal effect on Cyclops can be obtained stably by clarification process after chloramines pre-oxidation.