AWWA JAW48196

This article describes a method that virtually eliminates these limitations on total organic halogen (TOX) analysis and perhaps on analysis of certain individual disinfection by-products (DBPs) as well. The method is based on changes in the ultraviolet (UV) absorbance spectrum of NOM- (natural organic matter) containing solutions when they are chlorinated. Changes in the spectrum of NOM that are induced by removal or alteration of specific light-absorbing groups (chromophores) also provide insight into the reactivity and strucure of NOM molecules. The first part of the article reviews the fundamentals of UV absorbance and ways in which UV spectra of natural water can be analyzed. The second part describes an approach for using spectral data to understand and quantify DBP formation. Includes 24 references, tables, figures.