AWWA JAW66306
Journal AWWA - Plant Conversion Experience: Ozone BAC Process Installation and Disinfectant Residual Control
Journal Article by American Water Works Association, 04/01/2008
Marda, Saurabh; Kim, Doo-Il; Kim, Myung-Jong; Gordy, John; Pierpont, Skip; Gianatasio, Jim; Amirtharajah, Appiah; Kim, Jae-Hong
Full Description
The David L. Tippin Water Treatment Facility inTampa, Florida, recently added ozonation and biologicallyactivated carbon filtration and made additionalmodifications to its existing conventional treatmentprocess. The facility treats water that has relativelyhigh organic matter content, especially during high-rainfallseasons. After startup, unexpectedly lowmonochloramine formation efficiency and rapiddecay of monochloramine residual in treated waterswere observed. Similar problems associated with therapid decay of residual disinfectant have beenreported by other utilities.By changing the sequence of free chlorine andammonia injection and providing sufficient mixing andreaction time for free chlorine, the authors were able toincrease monochloramine formation efficiency. Filterbackwashing was also modified to successfully enhancefilter performance and stabilize monochloramine intreated waters.These findings and proposed solutions could be usefulfor many utilities experiencing similar problems or consideringconversion to monochloramine. The study methodsand results provided here could be used as a benchmarkfor other utilities to solve similar problems. Includes 35 references, tables, figures.