AWWA ACE71099

Ozonation of waters containing moderate to high levels of bromide, such as California StateProject Water, can form bromate at levels that may exceed the maximum contaminant level of10 µg/L. A proven technology to minimize the formation of bromate is to reduce the pH ofozonation (typically acidic). However, in waters with moderate or high alkalinity, the cost ofacid and caustic addition to lower and subsequently raise the pH of the water can be higher thanthe operating cost of ozone production alone. To lower costs, the Metropolitan Water District ofSouthern California has been conducting a long-term evaluation of the addition of ammonia andthen chlorine to form chloramines prior to ozonation as an alternative bromate control strategy.The primary objective of the study was to determine the effectiveness of the "ammonia-chlorine"process as a bromate control strategy while minimizing the formation of other disinfection byproductsof concern. This paper provides new insights into an emerging bromate controlstrategy, as well as a potential fatal flaw, the increased formation of N-nitrosodimethylamine intreated water. Includes 22 references, table, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2009

Number of Pages:

41

File Size:

1 file , 1.8 MB