DBP Formation Control by Modified Activated Carbons

Powdered or granular activated carbon adsorption has been widely used in drinking water treatment plants primarily for taste, odor, and synthetic organic contaminant (SOC) removal. However, carbon adsorption has not been widely used for controlling DOM due to the low equilibrium capacities and slow adsorption kinetics. The main reason for these drawbacks is that the majority of commercial activated carbons have been developed primarily to remove small molecular weight hydrophobic SOCs from water. As a result, many commercial carbons do not provide feasible engineering solutions for removing large molecular weight and heterogeneous mixtures of DBP precursors. This research was undertaken to develop a fundamental understanding of tailoring activated carbons for DBP control. The main objectives of this project were to (1) conduct a systematic investigation for developing a fundamental understanding of how activated carbons should be tailored for enhanced removal of dissolved organic matter (DOM) from natural waters; and (2) investigate the effectiveness of some carbon tailoring approaches for disinfection by-products (DBP) formation control at typical drinking water treatment conditions. This project showed that the removal of DBP precursor by GAC adsorption can be significantly improved. GAC adsorption, using modified GACs, can provide another alternative to some water utilities for meeting the Stage 2 requirements of the Disinfectant/Disinfection By-Products Rule.