AWWA WQTC60775

The interest in ozone for drinking water treatment in the United States hasincreased dramatically in recent years due to new regulations and concern overCryptosporidium and disinfection byproducts (DBPs). Ozone has manybenefits; however, its expense is significant and its placement in the treatmenttrain should be chosen with a sound understanding of its effect on other unitprocesses. In addition, the efficacy of ozone for controlling Cryptosporidium isnot as great as originally thought. Many utilities have designed and/orconstructed ozone facilities with a primary goal of inactivating Giardia andCryptosporidium. Many of these installations were based on the assumptionthat the CT for Cryptosporidium would be approximately 5 to 10 times the CTrequired for Giardia. The recently proposed (August 2003) Long Term 2Enhanced Surface Water Treatment Rule (LT2ESWTR) requires significantlyhigher CT values, which makes the use of ozone for Cryptosporidiuminactivation more difficult to totally unfeasible (depending on the desired loginactivation) during cold water conditions. The goal of this paper is to put theuse of ozone into perspective for utilities with existing ozone facilities and forthose considering its installation in the future. Includes 2 references, table, figures.

Product Details

Edition:

Vol. - No.

Published:

11/15/2004

Number of Pages:

10

File Size:

1 file , 350 KB