High performance size-exclusion chromatography (HPSEC) as a natural organic matter (NOM) property indicator in ion-exchange (IX) applications

Abstract

The main objective of this research was to develop an algorithm that would be able to relate ultraviolet absorbing moieties in potable water to disinfection by-products (DBP) and other water quality parameters. The separation was carried out using high performance size exclusion (HPSEC) chromatography to separate water samples based on size, while the developed algorithm used multi-spectral information extracted from 7 Manitoba source waters, and from those treated with ion-exchange (IX). Apparent molecular weight components between 2.2-4k Da were strongly associated with the formation of chlorinated by-products; as tested using Spearman and Pearson coefficients. Associations were found not to improve upon removal of the raw samples from the dataset; indicating that the applied methodology is not specific to the IX treatment used. Strong associations were also found between initial wavelengths of 226-239 nm and final wavelengths of 257-273 nm, which suggests that absorbing moieties in these ranges are of prime importance in the reaction mechanism to form DBPs.