Membrane filtration process is an advanced water treatment technology that has excellently removes turbidity and microorganisms. However, it is known that it has problems such as low economic efficiency and the operating stability. Therefore, this study was to evaluate on the economical feasibility and operational stability comparison of membrane and sand filtration process in Im-sil drinking water treatment plant. For the economic analysis of each process, the electricity cost and chemical consumption were compared. In the case of electric power consumption, electricity cost is 68.67KRW/㎥ for sand filtration and 79.98KRW/㎥ for membrane filtration, respectively. Therefore, membrane filtration process was about 16% higher than sand filtration process of electricity cost. While, the coagulant usage in the membrane filtration process was 43% lower than the sand filtration process. Thus, comparing the operation costs of the two processes, there is no significant difference in the operating cost of the membrane filtration process and the sand filtration process as 85.94KRW/m3 and 79.71KRW/m3 respectively (the sum of electricity and chemical cost). As a result of operating the membrane filtration process for 3 years including the winter season and the high turbidity period, the filtrated water turbidity was stable to less than 0.025 NTU irrespective of changes in the turbidity of raw water. And the CIP(Clean In Place) cycle turned out to be more than 1 year. Based on the results of this study, the membrane filtration process showed high performance of water quality, and it was also determined to have the economics and operation stability.

1. 서 론
 2. 연구방법
  2.1 임실정수장의 막여과 도입 배경 및 현황
   2.1.1 막여과 시설 도입 배경
   2.1.2 임실정수장 현황
  2.2 운영효율 평가 방법
   2.2.1 경제성 비교 평가
   2.2.2 막여과 공정의 운영 안정성 평가 방법
 3. 결과 및 고찰
  3.1 경제성 비교 평가 결과
   3.1.1 모래여과와 막여과 공정의 전력사용량 비교
   3.1.2 모래여과와 막여과 공정의 응집제 및 화학약품 사용량 비교
   3.1.3 모래여과와 막여과 공정의 톤당 생산단가 비교
   3.1.4 모래여과와 막여과 공정의 염소소비 특성 비교
  3.2 막여과 공정 도입을 통한 운영 안정성 개선사항
   3.2.1 정수 탁도 수질 안정성 향상
   3.2.2 막간차압의 운영안전성 확보
 4. 결 론
 References

• 변광진(임실군, 전북대학교 환경공학과, MSIL-GUN, Department of Environmental Engineering, Chonbuk National University) | Byeon, Kwangjin
• 장은수(금호산업, KUMHO Engineering&Construction) | Jang, Eunsu Corresponding author