AWWA ACE60049

Short-term disinfection byproduct (DBP) formation was impacted by bromide when the water was in contact withchlorine for times less than 4 hours. An increase in the bromide:total organic carbon (TOC) ratio resulted in an increaseof the percentage of brominated Trihalomethanes (THMs) and Haloacetic Acids (HAAs). However, the rate of TTHM kinetics (massand molar basis) were similar within the short-term, despite increasing the bromide:TOC ratiofor a given water. The dihaloacetic acids (DHAAs) and trihaloacetic acids (THAA) short-term kinetic rates were different, where DHAAsexhibited faster kinetics for times less than 1 hour. Also, bromine's greater halogenationefficiency and bromine's influence upon the mass yield (higher molecular weight) led to theformation of significant amounts of brominated species on a mass basis within the short-term.DHAAs were formed due to chloramines, but the prechlorine reaction consumed very fast-reacting(5 minutes) DHAA precursors, which would otherwise be formed if chloramines wereonly used. For one water some of the slow-reacting (5-20 days) DHAA precursors wereconsumed in the prechlorine reaction, whereas for the other two waters the long-term yields andkinetics did not differ for prechlorinated and nonprechlorinated natural organic matter (NOM). Includes 12 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

06/17/2004

Number of Pages:

16

File Size:

1 file , 360 KB