정수처리장에서 직분사 용존공기부상조와 맥동식 침전지의 Chl-a 제거특성 비교 연구

Abstract

This research was to compare the Chl-a removal characteristics of a direct-spraying dissolved air flotation(DAF) tank and a pulsator clarifier in water treatment plant. Alum(Aluminum sulfate) and PAC were used. The Chl-a removal efficiency during the operation of the direct-spraying DAF tank and the pulsator clarifier in the summer when algae is frequently generated were 68.3(25.0∼91.3) % and 39.1(9.1∼71.9) %, respectively. It was found that the direct-spraying DAF process is more effective than the pulsator clarifier in removing algae. In the case of the direct-spraying DAF tank, the correlation coefficient (R2) showed a high correlation of 0.8821 at Chl-a concentration below 20.0 mg/m³. Also, The change in removal efficiency was not significant at Chl-a concentrations above 20.0 mg/m³. In particular, the removal efficiency was less than 50 % at a Chl-a concentration below 8 mg/m3. Therefore, the direct-spraying DAF tank was more effective in removing algae than the pulsator clarifier, as it showed higher removal efficiency not only during the algal bloom period but also in the low Chl-a concentration. In terms of the economic feasibility of the direct-spraying DAF process, it is evaluated that the unit price of this algae removal technology is 21.47 won/m³.