AWWA ACE54312

Natural organic matter (NOM) has been observed to influence bromate (BrO3 - ) formation. Of particular interest is the application of ozone to source waters with low concentrations of ambient Br - and the influences that NOM exerts onBrO3 - formation. Fourteen source waters were ozonated at an applied O3 dose of 1 milligram per liter per milligram per liter of dissolved organic carbon (DOC). Experimental BrO3 - concentrations and ozone exposure (OE) values (a bench-scaleparameter used as an equivalent to the USEPA Ct-value for inactivation of pathogens) were used to present a method by which BrO3 - formation potentials of the source waters for any given OE could be estimated. Experimental results were correlated with water quality and operational parameters using a Pearson correlation matrix to investigate the influence of NOM characteristics. The NOM was characterized using DOC, UVA, SUVA, apparent molecular weight, and operationally defined fractions. Bromide concentration, SUVA, OE, hydrophobic-NOM by percent (HPO as %) and transphilic-NOM (TPI as %) were found to correlate well with BrO3 - formation, though no single NOM parameter based on mass was observedto correlate well. A forced regression analysis using the experimental data yielded rational models to assess BrO3 - formation in source waters using parameters that may be analyzed by a utility. Includes 13 references, tables, figures.