• 한국환경과학회지
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• 제16권1호
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• pp.81-94
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• 2007

The purpose of this work is to investigate the water quality change characteristics of treated water in water distribution systems of Water Treatment Plants (WTPs) of Jeju City. For this, the raw water, treated water and tap water that did not pass (named as not pass-tap water) and passed through the water storage tank (named as pass-tap water) were sampled and analyzed monthly from September 2001 to August 2002, for four (W, S, B and O) WTPs except for D WTP (where treated water is not supplied continuously) among WTPs of Jeju City. The concentrations of $NO_3^-$ and $Cl^-$ of treated water in distribution systems changed little, but changed seasonally, which is considered to be based on the seasonal variation of the quality of raw water. The pH of treated water changed little in distribution systems for S WTP, but for the other WTPs, the pH of not pass-tap water was similar to that of treated water and the pH of pass-tap water was higher than that of treated water. The turbidity of treated water in distribution systems changed little except for W2 of W WTP and S4 and S5 of S WTP, where it was higher than that of each treated water. The residual chlorine concentrations between treated water and not pass-tap water changed little, but those between treated water and pass-tap water changed greatly, based on the its long residence time in water storage tank and so its reaction with organic matter, etc or its evaporation. The concentrations of TTHMs (total trihalomethanes) and $CHCl_3$ that induce cancers in water distribution systems of these WTPs, were much lower than their water quality criteria and those in other cities. The concentrations of TTHMs of treated water and not pass-tap water were similar, but concentrations of pass-tap water were 1.5 to 2.0 times higher than those of treated water and not pass-tap water, due to the reaction of residual chlorine and organic matter, etc, with the result of long residence time in water storage tank.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.663-669
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• 1999

The objective of this study are to examine the feasbility of reuse treated sewage effluent ofr agricultural water, and to obtain basic data for estabilishment of rational agricultural water quality standard. From this study, it appears that reuse of treated sewage as a supplemental irrigation water could be feasible and practical alternative for ultimate sewage disposal which often causes water quality problem to the receiving water body. For full scale applicatiion, further study is recommended on the secific guidelines of major water quality components and publc health.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2001년도 춘계심포지움 및 학술발표회
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• pp.142-142
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• 2001

A national survey for enteric virus contamination in treated water and its source water was performed from March to November 1999. The water samples were subjected to virus filtration at the major water plants producing over 10$^5$ tons treated water per day. Twenty surveyed sites encompass most of heavily populated residential area except for Seoul and Pusan. (omitted)

• 한국환경과학회지
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• 제16권4호
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• pp.505-521
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• 2007

This study estimated response of water duality and pollutant behavior according to the discharge and reuse of treated wastewater by three-dimensional eco-hydrodynamic model, and suggest plan that water quality management and environmental restoration in the coastal area including urban stream of Yeosu, Korea. Dispersions of low-saline water and COD by treated wastewater loads (design facility capacity, about $110,000m^3/d$) were very limited in near of effluent site. Nutrients, however, increase compared to the other water quality factors, especially total nitrogen was very sensitive to input loads. When reuse some of treated wastewater to Yeondeung stream, nitrogen was big influence on estuarine water quality. Although current characteristics of treated wastewater such as discharge and water quality were negligible to the change of marine environment, effluent concentration of COD, TN and TP, especially 40% of TN, are reduced within the allowable pollutant loads for satisfy environmental capacity and recommended water duality criteria. Also, controls of input point/non-point sources to Yeondeung stream and base concentration of pollutants in coastal sea itself are very necessary.

• 대한토목학회논문집
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• 제40권1호
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• pp.127-133
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• 2020

해안에 위치한 대부분의 하수 처리장의 처리수는 직접 또는 하천을 통해 해안으로 배출된다. 따라서, 하수 처리장에서 배출되는 처리수의 수질은 하천 및 해안으로 방류되는 수질에 영향을 미친다. 본 연구에서는 연안에 인접한 하수처리장으로부터 배출되는 처리수가 연안 환경에 미치는 영향을 파악하기 위해 현장조사와 수치 시뮬레이션을 수행하였다. 해안에 미치는 영향을 파악하기 위해 처리수가 방류된 하천 및 하구 주변에서 채수된 시료로 수질과 저질을 분석한 결과, 하수처리장에서 배출된 처리수는 설계기준을 초과하지 않은 상태로 하천으로 방류되고 있으나, 하구를 통해 해안으로 방류되는 수질은 처리수보다 오염된 상태였다. 해안방류수의 수질악화에 대한 원인은 하구 주변에서 나타난 연안표사에 의해 하구가 일시적으로 퇴적되고, 하구폐색 현상이 발생하여, 하구에서의 정체시간이 증가함에 따라 처리수가 유입된 하천수가 하계에 부영양화되어 방류됨에 따라, 하구 주변에서 저질, 수질 및 해양 생물에 영향을 미치는 것으로 분석되었다. 따라서, 연안표사가 강한 동해안의 경우, 해양으로 방류되는 하수처리시설을 계획할 경우, 연안표사에 의한 하구폐색과 같은 처리수의 수질에 미치는 영향에 대한 면밀한 검토가 반드시 필요할 것으로 판단된다.

• 한국농공학회논문집
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• 제47권5호
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• pp.75-86
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• 2005

Recently since urbanization has brought about a dried stream and a worse water quality, Anyang city discharged the third treated sewage into the upper stream of Anyancheon and Hakuicheon. As the result, Hakuicheon had the water level and velocity enough for a living thing in the water to live in but water quality was worse than it had been. Therefore in case of meeting the water level and velocity of the second grade water-quality which living things in the water can live in, the discharge and water quality to secure in-stream flow must be at least 0.350 $m^3/s$ and $BOD_5\;3.2 mg/{\iota}$ respectively. In Anyancheon the water level was increased a little higher than it had been but the velocity was almost unchanged in comparison with it before. On the other hand the water quality was a little better than it had been. Therefore in case of meeting the water level and velocity of the third grade water-quality that people can do water-friendly activity, the discharge and water quality to secure in-stream flow must be at least 0.688 $m^3/s$ and $BOD_5\;4.8 mg/{\iota}$ respectively. The water-quality prediction on the suggested eight scenarios was simulated in all satisfying the third grade water-quality.

• 한국수자원학회논문집
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• 제36권5호
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• pp.863-878
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• 2003

본 연구에서는 하천의 유지용수를 확보하기 위하여 하수처리장에서 처리하여 방류하는 하수처리수를 활용하기 위한 방안을 검토하고 이를 하천유지용수로 직접 활용하기 위하여 역순환시스템의 활용을 검토하였다. 역순환시스템은 하천 하류에 위치한 하수처리장으로부터 방류되는 하수처리수를 펌핑하여 하천상류부로 이송함으로써 하천에 부족한 유지유량을 확보하는 방법으로 여러 가지 형태의 이송방안을 조합하여 하천의 특성에 맞는 최적의 시스템을 구성하고 간단한 수처리를 적용함으로서 하수처리수의 수질을 추가적으로 개선할 수 있는 특징이 있다. 또한 이송된 하수처리수를 하천에 유입시키는 방안들은 시각적으로 친수적인 경관을 제공하고 폭기 등에 의한 수질개선효과를 얻을 수 있다. 이러한 하수처리수를 활용한 역순환시스템을 하천유지용수확보에 적용하기 위하여 국내 하수처리장의 처리수 활용실태 및 수질 상태 등을 검토하였고, 국내의 하수처리수 활용 사례를 조사하였으며 외국의 유사사례 조사를 통해 국내에 적용하기 위한 방안을 마련하고 실제 하천을 대상으로 역순환시스템의 적용방안을 제시하였다.

• 환경영향평가
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• 제26권6호
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• pp.524-537
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• 2017

사후환경영향조사 결과의 신뢰도 제고에 대한 문제가 대두되어 왔으나 조사결과에 대한 객관적인 검증을 수행한 연구가 미흡한 실정이다. 본 연구에서는 개발 사업에 의한 수질영향을 조사하였고 그 결과를 바탕으로 사후환경영향조사 시 수질분야에 결과와 비교 분석을 수행하였다. 토석채취사업장 내 오수처리시설 최종방류수에 Biochemical oxygen demand(BOD), Suspended solid(SS), Total nitrogen(T-N), Total phosphorus(T-P) 농도가 높게 나타났다. 사후환경영향조사 결과와 비교한 결과, 오수처리시설 최종방류수의 BOD, SS, T-N, T-P 농도가 사후환경영향조사 시 분기별 농도의 사분범위(Interquartile range, IQR)와 최소값과 최대값의 농도범위보다 높게 나타났다(p<0.05). 체육시설(훈련원) 조성사업의 경우에는 오수처리시설 최종방류수에 BOD, SS, T-N, T-P가 높은 농도로 검출되었고 BOD와 SS 농도는 협의기준을 초과하였다. BOD와 SS 농도는 사후환경영향조사 시 오수처리시설 최종방류수의 농도와 유의한 차이를 나타냈다(p<0.05). 이러한 연구결과, 개발 사업 시 오수처리시설 최종방류수에 대한 체계적인 수질 모니터링과 적절한 수질관리가 수행되어야 할 것이다. 또한 사후환경영향조사결과의 신뢰도 제고를 위한 방안이 모색되어야 할 것이다.

• 상하수도학회지
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• 제34권6호
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• pp.463-471
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• 2020

A 1,000 ㎥/d DAF(dissolved air flotation) pilot plant was installed to evaluate the performance of the floating process using the Nakdong River. Efficiency of various DAF operations under different conditions, such as hydraulic loading rate, coagulant concentration was evaluated in the current research. The operation conditions were evaluated, based on the removal or turbidity, TOC(total organic carbon), THMFP(trihalomethane formation potential), Mn(manganese), and Al(aluminum). Also, particle size analysis of treated water by DAF was performed to examine the characteristics of particles existing in the treated water. The turbidity removal was higher than 90%, and it could be operated at 0.5 NTU or less, which is suitable for the drinking water quality standard. Turbidity, TOC, and THMFP resulted in stable water quality when replacing the coagulant from alum to PAC(poly aluminum chloride). A 100% removal of Chl-a was recorded during the summer period of the DAF operations. Mn removal was not as effective as where the removal did not satisfy the water quality standards for the majority of the operation period. Hydraulic loading of 10 m/h, and coagulant concentrations of 40 mg/L was determined to be the optimal operating conditions for turbidity and TOC removal. When the coagulant concentration increases, the Al concentration of the DAF treated water also increases, so coagulant injection control is required according to the raw water quality. Particle size distribution results indicated that particles larger than 25 ㎛ showed higher removal rates than smaller particles. The total particel count in the treated water was 2,214.7 counts/ml under the operation conditions of 10 m/h of hydraulic loading rate and coagulant concentrations of 60 mg/L.

• 한국수산과학회지
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• 제37권2호
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• pp.91-97
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• 2004

Applications of probiotics to shrimp ponds were carried out to determine their effects on water quality. Fermented solutions consisting of Bacillus spp. and Nitrosomonas spp. were applied to a 4 ha shrimp (Fenneropenaeus chinensis) pond from July to September, 2000. In the pond treated with probiotics, daily variations of DO and pH, and concentrations of DIN and DIP were lower than those in the ponds without probiotic treatment. Concentration of phytoplankton was less variable and the number of species was more variable in the probiotic-treated pond than those in the control pond. Variation of bacterial numbers and the number of Vibrio spp. were lower in the treated pond than those in the control pond. It is confirmed that the probiotics can be used to improve water quality of the shrimp ponds.