AWWA WQTC50363

In this research, a pilot-scale system was used to measure the effectiveness of ozone to inactivate Cryptosporidium parvum for the purpose of applying this technology as post-treatment of an open finished water reservoir. Since the maximum log inactivation of Cryptosporidium parvum in this pilot-scale study was 0.5, ozone was found to be an infeasible alternative to covering a reservoir. In contrast, bench-scale studies from other research reported herein, have shown that 2-log inactivation of Cryptosporidium by ozonation is achievable. Furthermore, since it has been suggested by other studies that in-vitro excystation underestimates the inactivation of Cryptosporidium oocysts following ozone disinfection and since excystation was used in this study, it is possible that the resulting inactivation was greater than estimated. Results from pilot-scale tests and subsequent bench-scale tests are summarized. Includes 9 references, tables, figures.