한강원수 자연유기물의 특성분석 및 강화응집 기준 평가

Abstract

The Disinfectants/Disinfection By-products(D/DBP) Rule proposed by the US Environmental Protection Agency requires the implementation of enhanced coagulation as a control strategy for natural organic matter(NOM) removal and as a means of limiting the formation of all DBPs, i.e., not just the trihalomethanes and haloacetica acids. To control DBP formation, several best available technologies(BATs) were determined for removal of DBPs and DBP precursors. The enhanced coagulation is one of the BATs for DBP precursors removal. Treatment facilities that achieve a specified percent removal of total organic carbon(TOC) prior to the application of a continuous disinfectant or that achieve a residual TOC concentration < 2 mg/L prior to the application of a continuous disinfectant are considered to be in compliance with enhanced coagulation. The enhanced coagulation was applied to raw water in Korea, the Han River. Raw water were examined and effects of different raw water qualities on enhanced coagulation were investigated. Three analyses were used for raw water characteristics, water quality measurement, molecular weight distributions, hydrophobic/hydrophilic fractionation. The Han River had the relatively low alkalinity and low organic carbon concentration. The results of molecular weight distributions showed significant portions of low molecular weight organics, which is very different from most water in USA. The alum doses for the required TOC removal guided from USEPA manual were quite low(i.e. 10~30 mg/L alum) for the water, probably due to the specific water quality of the Han River.