AWWA WQTC52871

The inactivation kinetics of Cryptosporidium parvum with ultraviolet (UV) light(254 nm) in single and sequential disinfection schemes was studied usingmonochloramine and free chlorine as the secondary disinfectants. C. parvumviability was assessed using the modified in-vitro excystation method developedby Rennecker et al., which has been shown to be consistent with animalinfectivity for chemical disinfection. Studies have suggested that excystationand infectivity data do not agree in the case of UV disinfection; however, adirect comparison of the various viability/infectivity assessment methods hasnever been completed. The overall objective of this study is tocompare C. parvum inactivation data obtained by modified in-vitro excystation,animal infectivity, and cell culture assays. The modified in vitro excystationdata portion of the study is presented in this paper. Includes 17 references, figures.