The Effect of Natural Organic Matter Variation and Pipe Deposit Material on Disinfection Byproduct Formation
Author: Nicholas Golden
Publisher:
Published: 2005
Total Pages: 208
ISBN-13:
DOWNLOAD EBOOK"Disinfection byproduct (DBP) formation bottle tests were performed on municipally treated drinking water samples obtained during the period from 9/15/03 to 11/24/03 with samples being taken post-filtration but before final chlorination from the City of Akron water treatment plant. Samples were chlorinated under two conditions in small amber bottles; aqueous-only system and in the presence of powdered goethite, a representative pipe deposit material, under the same pH and initial chlorine dose. The natural organic matter (NOM) in each of the water samples was analyzed for initial values of TOC, UV254, SUVA, and six relative fluorescence fractions and for the six relative fluorescence fractions after adsorption equilibrium with the powdered goethite. Disinfection byproduct formation was then correlated to these natural organic matter measurements. The NOM measurements were shown to vary, sometimes greatly, even within very short sampling periods suggesting that the nature and reactivity of the NOM can fluctuate over relatively short periods of time. TOC, UV254, and SUVA values did not correlate well with DBP formation, individually. The six relative fluorescence fractions when used along with SUVA correlated well with DBP formation for the aqueous-only system and were correlated well with trihalomethane (THM) formation for the goethite system. Disinfection byproduct formation was impacted greatly with the presence of the representative pipe deposit material, goethite. Average increases of 44 ppb, 39 ppb, and 40 ppb were found for total DBP, total THM, and chloroform formation with the goethite system having a much greater efficiency of DBP formation with equal amounts of TOC as the aqueous-only system. The goethite also impacted speciation of the THM and haloacetic acids (HAA) with the goethite system showing large increases in chloroform with little changes in bromodichloromethane (BDCM) formation. HAA species also changed significantly with the majority of the sample waters showing an increase in dichloroacetic acid (DCAA) and a decrease in trichloroacetic acid (TCAA) yielding little to no change in total HAA formation. Correlation of HAA formation with NOM measurements yielded little results possibly due to competitive degradation reactions of TCAA and DCAA."--Abstract.