Premium
Pilot‐scale evaluation of nitrification control strategies
Author(s) -
Harrington Gregory W.,
Noguera Daniel R.,
Kandou Alicia I.,
Vanhoven David J.
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.tb10232.x
Subject(s) - nitrification , chloramination , chloramine , environmental chemistry , biocide , chemistry , ammonia , environmental engineering , chlorine , environmental science , nitrogen , biochemistry , organic chemistry
A significant concern associated with chloramination is nitrification caused by the growth of ammonia‐oxidizing bacteria (AOB) in the distribution system. To prevent nitrification, any measures designed to slow the decay of chloramine and its associated release of ammonia should theoretically reduce the occurrence of AOB growth. Pilot‐scale studies were used to evaluate whether enhanced removal of natural organic matter and pH adjustment delayed the onset of nitrification. For the system described in this article, nitrification occurred at pH values ranging from 7.9 to 8.9, with the time to onset of nitrification being fastest at about pH 8.5. However, pretreatment with enhanced coagulation successfully delayed the onset of nitrification compared with pretreatment with conventional coagulation. Nitrification did not occur when total chlorine concentrations were 2.2 mg/L as Cl 2 or more. Similarly, nitrification did not occur in locations with biocide‐to‐food ratios of 1.9 mg Cl 2 /mg N or more.