This study aimed for evaluating the applicability of the two stage dual media filtration system in field water treatment plant. The field plant of two stage and dual media filtration system was operated for 2 months. Average iron concentrations of the settled water, existing filtered water and second stage filtered water was 0.041 mg/L, 0.007 mg/L and 0.005 mg/L, respectively. Removal efficiency of iron concentration in the second stage is appropriately 35% more than in existing filtered water. Also removal efficiency of residual chlorine in the dual media filtration system is relatively 42.3% more than in existing filtered water due to adsorption of activated carbon, but the removal of ammonia nitrogen by adsorption is insufficient. Average concentrations of THM and chloroform in the settled water are 0.033 mg/L, 0.026 mg/L, respectively and in existing filtered water are 0.023 mg/L and 0.023 mg/L. Average concentrations of THM and chloroform in the dual media filtration system are 0.008 mg/L and 0.013 mg/L. Therefore removal efficiency of THM concentration in second stage is more than 66.4% in existing filtrated water. Also removal efficiency of chloroform in the dual media filtration system is more than 50.0% in existing filtered water because of the adsorption of activated carbon. In this case backwashing period in dual stage system is 4～5 days, but in existing filtration system is 1～2 days.

Abstract
 1. 서 론
 2. 실험장치 및 방법
 3. 결과 및 고찰
 4. 결 론
 참 고 문 헌

• 조관형(청운대학교) | Kwanhyung Jo (Department of Civil and Environmental Engineering, Chungwoon University) Corresponding author
• 채수권(을지대학교) | Su-Kweon Chae (Department of Environmental Health and Safety, Eulji University)
• 황병기(상명대학교) | Byung-Gi Hwang (Department of Civil Engineering, Sangmyung University)
• 김준언(효성에바라엔지니어링) | Jooneon Kim (Hyosung Ebara Engineering Co.)
• 우달식(한국계면공학연구소) | Dal-Sik Woo (Korea Interfacial Science and Engineering Institute)