Haloacetic acids (HAAs) concentrations have been observed to decreased at drinking water distribution system extremities. This decrease is associated with microbiological degradation by pipe wall biofilm. The objective of this study was to evaluate HAAs degradation in a drinking water system in the presence of a biofilm and to identify the factors that influence this degradation. Degradation of monochloroacetic acid (MCAA), dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) was observed in a simulated distribution system. The results obtained showed that different parameters came into play simultaneously in the degradation of HAAs, including retention time, water temperature, biomass, and composition of organic matter. Seasonal variations had a major effect on HAAs degradation and biomass quantity (ATP concentration) was lower by 25% in the winter compared with the summer.

Abstract
 1. 서 론
 2. 실험재료 및 방법
  2.1. Pilot 규모의 모의 관망 및 운전
  2.2. 분석
 3. 결과 및 고찰
  3.1. 운전기간에 따른 모의관망 내의 생물막 형성
  3.2. 계절 변화에 따른 HAA 3종의 생분해 특성
  3.3. 생물막에 의한 HAA 3종의 생물분해 동력학 평가
 4. 결론
 감사의 글
 참고문헌

• 손희종(부산광역시 상수도사업본부 수질연구소) | Hee-Jong Son (Water Quality Institute, Water authority)
• 김도환(부산광역시 상수도사업본부 수질연구소) | Do-Hwan Kim (Water Quality Institute, Water authority)
• 한영립(동아대학교 환경공학과) | Young-Rip Han (Department of Environmental Engineering, Dong-A University)
• 최영익(동아대학교 환경공학과) | Young-Ik Choi (Department of Environmental Engineering, Dong-A University) Corresponding author