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A proposed C × T table for the synergistic inactivation of Cryptosporidium with ozone and chloramine
Author(s) -
Najm Issam,
Rakness Kerwin,
Hotaling Michael,
Via Steve,
Rexing David
Publication year - 2004
Publication title -
journal ‐ american water works association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.466
H-Index - 74
eISSN - 1551-8833
pISSN - 0003-150X
DOI - 10.1002/j.1551-8833.2004.tb10784.x
Subject(s) - chloramine , cryptosporidium , ozone , chlorine , chemistry , downstream (manufacturing) , environmental chemistry , water treatment , environmental science , microbiology and biotechnology , biology , environmental engineering , organic chemistry , operations management , economics , feces
Several studies have investigated the possible synergy between ozone and chloramine and between ozone and chlorine for the inactivation of Cryptosporidium oocysts. This article includes a pooled analysis of three published data sets collected by different research groups using different analytical techniques. The analysis shows that significant inactivation of Cryptosporidium oocysts with chloramine can be achieved downstream of exposure to ozone. An empirical model is proposed to incorporate upstream inactivation with ozone into the calculation of the Cryptosporidium log inactivation with downstream chloramine. Using this model, the authors developed C × T tables for the inactivation of Cryptosporidium with chloramine downstream of various levels of inactivation with ozone. Synergistic inactivation with extended chloramine contact time downstream of ozone can provide substantial benefits to water treatment plants.