Effect of Ozone and GAC Process for the Treatment of Micropollutants and DBPs Control in Drinking Water: Pilot Scale Evaluation

Abstract

Abstract To improve the quality of water supplied to the City of Seoul in Korea, a pilot-scale evaluation of how the conventional treatment process could be upgraded was conducted. Three candidate processes were evaluated and compared: a conventional process (consisting of coagulation, sedimentation, and rapid sand filtration) plus GAC (Train A); a conventional process plus ozone and GAC (Train B); and a process consisting of coagulation, sedimentation, intermediate ozone, sand filtration, and GAC (Train C). Treatment efficiency of the unit process and overall treatment trains were evaluated using several parameters such as turbidity, dissolved organic carbon (DOC), UV absorbance at 254 nm (UV254), specific ultraviolet absorbance (SUVA), micropollutants (pesticides, benzenes, and phenols), disinfection by-products (trihalomethanes (THMs), haloacetic acids (HAAs) and aldehydes), and total organic halogen (TOX). Results showed that ozone and/or GAC was effective for removing micropollutants and controlling chlorinated by-products such as THMs and HAAs. However, any synergistic effect of ozonation (adsorption and biodegradation) on GAC was observed due to the low concentration of aldehydes in raw and process water. Keywords: OzoneGACDisinfection By-ProductsMicropollutantsSeoul Waterworks Acknowledgment This research was sponsored by the Waterworks Research Institute in Korea. Authors are thankful for the support of this fund. Notes Federal Register Natural Interim Primary Drinking Water Regulations, 44, 68, 624 (1979). Federal Register, Natural Primary Drinking Water Regulations: Disinfectants and Disinfection By-Products; Final Rule p63, 69, 389 (1998). 21. Rice, R. G., “Emerging Technologies for Compliance with Disinfection and Disinfection By-Products Regulations,” Presented at EPA Workshops on Emerging Technologies for Drinking Water Treatment, (1987–1988). 25. US EPA, Methods for the Determination of Organic Compounds in Drinking Water: Supplement 2, EPA 600R92129 (1992). 26. US EPA, Methods for the Determination of Organic Compounds in Drinking Water: Supplement 3, EPA 600R95131 (1995).