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Kinetics of Nitrosomonas europaea INACTIVATION by chloramine
Author(s) -
Oldenburg Patrick S.,
Regan John M.,
Harrington Gregory W.,
Noguera Daniel R.
Publication year - 2002
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.1551-8833.2002.tb09561.x
Subject(s) - nitrosomonas europaea , chloramine , nitrification , nitrosomonas , chemistry , bacteria , ammonia , microbiology and biotechnology , incubation , environmental chemistry , nuclear chemistry , biology , biochemistry , chlorine , nitrogen , organic chemistry , genetics
The effect of pH on the inactivation of Nitrosomonas europaea by chloramines was tested for a range of chloramine concentrations. Cell viability was assessed using the most probable number (MPN) technique and a culture‐independent bacterial viability test. For pH 7 to 9, N. europaea inactivation followed Chick‐Watson kinetics with n = 1 and k ranging from 2.5 × 10 –03 L/(mgCl 2 ·min) at pH 7 to 2.4 × 10 –04 L/(mgCl 2 ·min) at pH 9 in the bacterial viability–based tests. For the MPN‐based tests, k was approximately 1,000‐fold higher. Although CT 99 values from the MPN‐based experiments agreed with CT 99 reported elsewhere for ammonia‐oxidizing bacteria (AOB), the lower inactivation rates estimated from the bacterial viability tests were more consistent with AOB persistence in distribution systems, suggesting that MPN may overestimate chloramine biocide effectiveness. Finally, the counteracting effect of pH on N. europaea inactivation and chloramine decay indicates that pH control is likely to have a site‐specific effect on nitrification.