AWWA ACE58230

Natural organic matter (NOM) hinders adsorption of trace organic compounds by powdered activated carbon (PAC) via two mechanisms: direct site competition by small, strongly adsorbing molecules, and pore blockage by large molecules. Li et al. (2002) developed a three-component model, COMPSORB, to describe atrazine adsorption in continuous flow PAC/membrane systems by using two model compounds to represent strongly competing and pore blocking fractions of NOM, respectively. The primary objective of this research was to show that COMPSORB can be applied to natural water systems. In this research the authors established a quantitative analytical method to determine the necessary NOM characteristics so that the 3-component model can be used to predict PAC performance in continuous-flow PAC/membrane systems. NOM was differentiated into two fictive fractions based on adsorptive characteristics and competition mechanisms in order to obtain equilibrium and kinetic parameters for these fractions from batch test data. Model prediction using these data to predict atrazine removal in a PAC/membrane system treating natural water were conducted, as well as the real PAC/MF experiments using natural water. The results show promising results in characterizing NOM for prediction of PAC performance in water treatment. Includes 8 references, tables, figures.