Evaluation of organic precursors removed by ozonation and GAC processes

The purpose of this research is to investigate the effectiveness of pre-ozonation and the activated carbon process in removing three organic precursors and their disinfection by-products (DBPs) from water samples. These precursors include Humic Acid, p-Hydroxybenzoic Acid and Hydroquinone. Results from this research indicate that activated carbon with large pore size (GAC, F-400) was effective in adsorbing precursors with higher molecular weight and was ineffective in adsorbing low molecular weight precurssors (p-Hydroxybenzoic Acid and Hydroquinone). Since high molecular weight precursors were more attracted toward adsorption sites, this phenomena caused desorption of low molecular weight precursors and resulted in an increase of formation potential of total organic carbon (TOC) in the water stream.