Comparison of ozone and permanganate as preoxidant on treating eutrophic raw water

摘要

A pilot-scale study, using ozone and potassium permanganate as preoxidant, was conducted to examine their effects on algae, turbidity, and organic matter removal by coagulation. Continuous operation of two parallel treatment trains with or without the two preoidants was carried out. The results show that adding either ozone or permanganate as preoxidants could enhance algae removal by coagulation. The removal of green algae (Chloella sp.) was found to be lower than those of diatoms and blue-green algae. There are optimum dosages for both preoxidants. As ozone dosage exceeded optimum value, the algae and turbidity removal deteriorated significantly. However, regardless of preoxidant dosage tested, the ozone had better performance in the NPDOC, A254, and THMFP removal, as compared to permanganate.