The Dongbok lake water before and after alum coagulation and activated carbon adsorption were analyzed in terms of organic contents, molecular weight distributuin (MWD), and UV-absorbance. Dissolved organic compounds in the Dongbok lake were fractionated into three molecular size classes by gel permeation chromatography. The fractionation was reasonably successful in isolating compounds with MW>10,000 (Fraction Ⅰ) and those with 3,000MW (Fraction Ⅲ. The bulk of the dissolved carbon was present in compounds of molecular weight in the range of 3,000∼10,000. Alum coagulation preferentially treated molecules of high molecular weight, which has molecules larger than 10,000. The dissolved organic carbon (DOC) removal after activated carbon adsorption was high in the Fraction Ⅱ, Ⅲ. The A_260/DOC ratio after alum and activated carbon treatment was high in the Fraction Ⅰ, Ⅱ. This results suggest that the organics remaining after each treatment has a trihalomethane formation potential

• 정경훈(조선대학교 환경공학부) | Kyung-Hoon Cheong (Division of Environmental Engineering, Chosun University)
• 최형일(조선대학교 환경공학부) | Hyung-II Choi (Division of Environmental Engineering, Chosun University)
• 정오진(조선대학교 환경공학부) | Oh-Jin Jung (Division of Environmental Engineering, Chosun University)
• 손인규(광주광역시 환경관리과) | In-Gyu Son (Environmental Management division, Kwangju Metropolitan city)