Controlling Cryptosporidium oocysts using conventional treatment

Fourteen pilot-scale tests were performed to assess the ability of conventi onal treatment to control Cryptosporidium oocysts and three surrogates: tur bidity, total particle count, and aerobic endospores. Cryptosporidium oocys ts were fed into the raw water at a target concentration of 10(6)/L for 30- 71 h in each test. The effects of coagulant type, coagulant dose, raw water quality, filter loading rates, and filter media were evaluated. Under opti mal coagulation conditions, conventional treatment achieved more than 4-log total Cryptosporidium removal, and surrogate log removals were conservativ e (low with respect to Cryptosporidium).