In the coagulation/sedimentation (C/S) process of the water treatment process, the inflow of massive algal bloom causes many problems including fouling of filter media. This study was conducted to find out the way to remove the algae’s harmful effects by addition of pre-treatment prior to C/S process. Many Jar-tests were conducted such as ① ACF (Algae Coagulation·Flotation) process using natural algae coagulant (Water Health®), ② ACF + C/S process and ③ C/S process with a variety of conditions using cultured algae. The average values of turbidity were ① 0.42 NTU for ACF process, ② 0.13 NTU for ACF + C/S process and ③ 0.25 NTU for C/S process. It was shown that the treatment efficiency of ACF process could get low turbidity results, and ACF + C/S process could achieve more efficient results than those of C/S process. Any negative effects of ACF process to the efficiency of C/S process were not observed in ACF + C/S process. In order to reduce the unfavorable effects of algae, it was found out that the introduction of ACF process in the forms of ① ACF or ② ACF + C/S could be one of the effective and alternative solutions.

• 장여주(에덴녹화산업(주)) | Yeo-Ju Jang (E.D.R Landscaping Industry Co., LTD.)
• 정진홍(한국건설기술연구원 환경･플랜트연구소) | Jin-Hong Jung (Environmental and Plant Engineering Research Institute, Korea Institute of Civil Engineering and Building Technology,)
• 임현만(한국건설기술연구원 환경･플랜트연구소) | Hyun-Man Lim (Environmental and Plant Engineering Research Institute, Korea Institute of Civil Engineering and Building Technology,)
• 장향연(과학기술연합대학원대학교 건설환경공학과) | Hyang-Youn Chang (University of Science & Technology)
• 김원재(한국건설기술연구원 환경･플랜트연구소) | Weon-Jae Kim (Environmental and Plant Engineering Research Institute, Korea Institute of Civil Engineering and Building Technology,) Corresponding author