To remove phosphorus from the effluent of public wastewater treatment facilities, hundreds of enhanced phosphorus treatment processes have been introduced nationwide. However, these processes have a few problems including excessive maintenance cost and sludge production caused by inappropriate coagulant injection. Therefore, the optimal decision of coagulant dosage and automatic control of coagulant injection are essential. To overcome the drawbacks of conventional phosphorus removal processes, the integrated sedimentation and dissolved air flotation(SeDAF) process has been developed and a demonstration plant(capacity: 100 m3/d) has also been installed. In this study, various jar-tests(sedimentation and / or sedimentation·flotation) and multiple regression analyses have been performed. Particularly, we have highlighted the decision–making algorithms of optimal coagulant dosage to improve the applicability of the SeDAF process. As a result, the sedimentation jar-test could be a simple and reliable method for the decision of appropriate coagulant dosage in field condition of the SeDAF process. And, we have found that the SeDAF process can save 30 – 40% of coagulant dosage compared with conventional sedimentation processes to achieve total phosphorus (T-P) concentration below 0.2 mg/L of treated water, and it can also reduce same portion of sludge production.

ABSTRACT
1. 서 론
2. 연구방법 혹은 재료 및 실험방법
    2.1 일체형 침전부상공정(SeDAF)의 개요
    2.2 Jar-test 기반 침전 및 침전부상공정 모의실험개요
    2.3 최적처리조건의 정의
    2.4 실증플랜트를 활용한 침전부상공정의 실규모 검증
    2.5 분석도구 및 기기
3. 결과 및 고찰
    3.1 침전 및 침전부상공정의 최적 응집제 주입농도도출
    3.2 침전 및 침전부상공정에 대한 응집제 주입농도관계식 도출
    3.3 현장적용성 제고를 위한 응집제 주입농도 결정기법 검토
    3.4 현장적용성 제고를 위한 응집제 주입농도 자동제어기법 제안
4. 결 론
References

• 장여주(과학기술연합대학원대학교 건설환경공학) | Yeoju Jang (Civil & Environmental Engineering, University of Science and Technology (UST, KICT school))
• 정진홍(한국건설기술연구원 국토보전연구본부 환경자원재생연구센터) | Jinhong Jung (Department of Land, Water and Environment Research, Korea Institute of Civil Engineering and Building Technology (KICT))
• 김원재(한국건설기술연구원 국토보전연구본부 환경자원재생연구센터) | Weonjae Kim (Department of Land, Water and Environment Research, Korea Institute of Civil Engineering and Building Technology (KICT)) Corresponding author