AWWA WQTC58820

The aims of this study were twofold: to compare the effects of six water treatment processes on the concentration and character of the natural organic matter (NOM) in one reservoir water; and, to determine how relatively unsophisticated techniques, that would be available on a routine basis to most water authorities, could be utilized in day to day operations to help water treatment personnel understand their NOM, and therefore aid in the optimization of plant processes. Myponga Reservoir water was chosen for this study as it has a low turbidity and relatively high dissolved organic carbon (DOC) concentration (12.4 mg L-1), so the effects of the different processes over a wide range of DOC and ultraviolet (UV) absorbance removals could be investigated. Six water treatment processes were studied: alum coagulation; MIEX®¹ DOC; activated carbon; biological filtration; ozonation; and, chlorination. All together, 127 samples were analyzed for dissolved organic carbon concentration, UV scans, true color, and molecular weight distribution using high performance size exclusion chromatography (HPSEC). Specific UV absorbance at 254 nm (SUVA=UV absorbance/DOC) was calculated for all samples. The chlorinated samples were also analyzed for trihalomethane (THM) formation. Selected results are discussed in this paper. Includes 5 references, figures.