Effects of EBCT and water temperature on HAA removal using BAC

This article discusses the removal of a major group of disinfection by-products (DBFs) - haloacetic acids (HAAs) - in biologically active carbon (BAC) or acclimated granular activated carbon (GAC). Precursor removal has been the main control strategy for DBPs. Using BAC to remove preformed HAAs is a new concept. Although it is known that water temperature and empty bed contact time (EBCT) affect the removal of HAAs in BAC, this study was undertaken to gain a better understanding of how these parameters affect removal. The results suggest that a 10-min EBCT should be used for 4°C waters and a 5-min EBCT should be used for waters at 10°C or higher. The results of this study could help utility managers better control HAAs by improving the general understanding of the effects of water temperature and EBCT. Information on HAA removal could be used to provide an alternative technique for HAA control. Water suppliers could use the information to improve the design and operation of GAC filters to achieve an effective reduction of HAAs. Enhanced HAA removal could help the water industry better comply with DBP regulations, improve water quality, and protect public health.