하수처리장 2차처리수 재이용 잠재성 평가 = Feasibility evaluation of secondary effluent from sewage treatment plant for reuse

다국어 초록 (Multilingual Abstract)

Korea has suffered from chronic water shortage problem due to severe seasonal variation of rainfall and locally unbalanced distribution of water resource. Recently, industrial development has involved population growth around urban areas and has created more water demand bath domestic and industrial purposes. Without special countermeasures, water shortage problem is expected to grow rapidly in the future.
As of 2002, two-hundreds of publicly owned wastewater treatment plant(POWTP) are constructed and operated. From these plant, about twenty million tons of the effluent(from domestic wastewater) are daily discharged into water bodies, which amounts to significant portion of total attainable water resources.
Recently, reuse of the effluent has been becoming major issues for various sides of government organizations, academic fields and water industries to use potentially one of the most stable sources of water thus preparing for possible water shortage in the future.
Reuse system of the effluent was introduced in 1991 by the revision of waterworks law. However, its practical application is still at the initial stage. Since 1990, some reuse studies were started, but most of the studies have been focused mostly on developing treatment processes for specific reuse purpose, but the effluent itself such as statistical aspects and stability of the water qualities have not been studied yet for evaluating the reuse potential.
This study contents were consisted of three part. In first subject, effect of the various sampling frequencies on the performance was investigated by using 1-year effluent data. There was no significant difference between results by daily sampling and by a five-day interval sampling. In addition, the result was the same for both of the tests extracted data sets equally and randomly. When the variation of effluent quality during the period of five-days interval sampling exceeds a permit criteria(sum of the mean and standard deviation), we have to switch back to daily sampling until the data meet the criteria. For the BOD_(5), it took four consecutive days of sampling from five-days sampling frequency to return the criteria.
In second subject, nine plants from whole two-hundred POWTPs were selected. Effluent from those plants was intensively monitored during one years period. Their performances, stabilities, and reuse potentials were evaluated in terms of suitability for specific reuse. Most of the water quality parameters were log normally distributed as reported in literature. The stability coefficients proved stable through the period study except for several plants. Reuse potential was evaluated by comparing its criteria(or guideline) with effluent quality. Most of the parameters were acceptable for agricultural and stream flow except organic matters, coliform bacteria and lead. To satisfy the organic matter's water criteria for reuse, it needed at least sand filteration and activated carbon process. The result of the cost and benefit analysis showed that the recycle rate should be over 25% for charge. The study also showed that it was more beneficial to design 20,000 ton/day for the bigger scale plants and 7,000 ton/day for the small and medium scale plants when the reuse rate was 25% of the recycle rate. If we are going to supply the secondary effluent for stream flow and agricultural reuse, we need to set the proper nutrient control and add the proper nutrient items to the water quality criteria.

목차 (Table of Contents)

• 목차
• Content
• Table List
• Figure List
• 1. 서론 = 1
• 1.1 연구의 배경 및 필요성 = 1
• 1.2 연구의 목적 = 3
• 1.3 연구의 대상과 범위 = 4
• 1.4 연구의 기대효과 및 활용방안 = 5
• 2. 문헌연구 = 6
• 2.1 국내 물 수급 = 6
• 2.1.1 현황 및 대안 = 6
• 2.2 국내 하수처리장 현황 = 8
• 2.2.1 하수처리장 가동 현황 = 8
• 2.2.2 하수처리수 재이용 현황 = 9
• 2.2.3 재이용 방식 = 10
• 2.3 재이용 관련 법적 제도적 장치 = 12
• 2.3.1 국내 재이용 제도적 장치 = 12
• 2.3.2 외국의 재이용 제도적 장치 = 16
• 2.4 통계학적 분석 = 27
• 2.4.1 산포도 = 27
• 2.4.2 확률분포 = 28
• 2.4.3 안정도와 신뢰도 = 31
• 2.5 재이용 시설 = 32
• 2.5.1 하수 2차처리수 재이용 시설 = 32
• 2.5.2 재이용 용도별 처리 공정 = 37
• 2.5.3 재이용 재원 지원 제도 = 39
• 2.6 하수 2차처리수 재이용시설 운영 사례 = 43
• 2.6.1 국내의 재이용 사례 = 43
• 2.6.2 일본의 재이용 사례 = 44
• 2.6.3 미국의 재이용 사례 = 46
• 2.6.4 기타 지역의 재이용 사례 = 48
• 3. 연구내용 및 방법 = 51
• 3.1 하수처리장 운전관리를 위한 샘플링 빈도 결정 = 51
• 3.2 하수 2차처리수 재이용 잠재성 평가 = 52
• 3.2.1 연구대상 처리장 선정 = 52
• 3.2.2 모니터링 항목 = 55
• 3.3 하수처리수에 의한 방류하천 영향 = 56
• 4. 결과 및 분석 = 58
• 4.1 운전관리를 위한 방류수 샘플링 빈도 결정 = 58
• 4.1.1 분석대상 하수처리장 방류수 수질자료 = 58
• 4.1.2 등 간격 샘플링 결과 = 61
• 4.1.3 무작위 샘플링 검토결과 = 69
• 4.1.4 기준치 초과기간 분석 = 73
• 4.1.5. 운전관리를 위한 샘플링 빈도 결정 = 75
• 4.2 하수 2차처리수 수질현황 및 특성 = 76
• 4.2.1 표본하수처리장 방류수의 수질 확률분포 = 76
• 4.2.2 전체 연구대상 하수처리장 = 86
• 4.2.3 연구대상 하수 처리장 2차 처리수의 수질특성 = 95
• 4.3 하수 2차처리수 재이용 잠재성 평가 = 111
• 4.3.1 질적 잠재성 평가 = 111
• 4.3.2 2차처리수 재이용 잠재성 향상방안 = 118
• 4.3.3 재이용 경제성 분석 = 128
• 4.4 하수 2차처리수에 의한 방류하천 수질변화 = 139
• 4.4.1 방류하천 수질 검토 개요 = 139
• 4.4.2 표본하수처리장 방류하천 수질변화 = 141
• 4.4.3 하수처리장 2차처리수에 의한 방류하천 수질변화 = 146
• 5. 결론 = 147
• Reference = 150