AWWA JAW59040

A demonstration-scale study was undertaken to evaluatepH suppression and ammonia addition tocontrol bromate formation under disinfectionconditions for Cryptosporidium. Specific researchobjectives included determining the effects of seasonalbromide changes on bromate formation over a range ofpH values and assessing control of bromate over avariety of ammonia doses, at varying disinfection levels,and at different pH values.Tests were conducted on two sample waters withvarying levels of alkalinity, bromide, and total organiccarbon. Although pH control did limit bromate formation,the strategy was found to be relatively expensivebecause of the large chemical dosages required. As abromate control method, ammonia proved sourcewater-specific, with a higher rate of success in high-alkalinitywaters than in those with lower alkalinity.Furthermore, ammonia addition must be carefullybalanced with the need to provide secondary disinfectionwith chlorine or chloramines.Many water suppliers in the southwestern UnitedStates rely on the source waters tested in this work orare using water with moderate-to-high bromide levels.This research offers direction, practical guidance, andcost analyses for utilities that are considering usingozone or changing their existing ozone practice. Includes 37 references, tables, figures.

Product Details

Edition:

Vol. 95 - No. 10

Published:

10/01/2003

Number of Pages:

12

File Size:

1 file , 290 KB