• 한국습지학회지
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• 제18권1호
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• pp.24-31
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• 2016

도시화에 따른 불투수면 증가로 인한 자연적 물순환 시스템 왜곡 현상과 더불어 불투수면에 축적된 다양한 오염물질은 강우 시 유역 및 하천으로 유입되어 다양한 오염을 일으킨다. 특히 대부분의 강우가 여름철에 집중되는 국내 계절적 특성은 집중호우에 따른 비점오염물질의 수계 과대 유입에 대한 우려를 높이고 있어, 이를 효과적으로 처리하고 재이용하기 위한 다양한 형태의 빗물처리 및 재이용 시설에 대한 연구가 필요하다. 이를 위해 본 연구에서는 강우시 지붕 유출수의 오염특성을 파악하고, 강우 초기 고농도 빗물 유출수를 효과적으로 처리하기 위한 소규모의 빗물정원 포함 형태의 빗물처리시설을 구성하였으며, 처리시설에 포함된 빗물정원에서의 오염물질 처리 효율을 높이기 위해 실험실 규모의 인공강우를 이용한 다양한 여재 구성 오염물질(TN, TP, CODcr) 제거율 실험을 실시하였다. 이를 통해 제거효율이 가장 높은 피트머스(Peatmoss)와 자갈, 모래를 구성된 빗물정원을 시범유역에 설치하여 오염물질 제거효율을 측정하였다. 2015년 6월 ~ 7월까지 4회의 실제 강우에 대한 강우사상별 시간별, 강우사상별, 농도별 오염물질 제거율을 분석 한 결과 강우강도가 높거나 강우량이 커질수록 고농도의 오염물질이 빗물처리시설 내 빗물정원으로 유입되었으며, 분석 결과 오염물질의 제거율은 저농도 일 때 보다 고농도 일 때 더 높은 것으로 나타났다. 대규모의 빗물처리시설을 설치하기 어려운 도심지에서, 위와 같은 소규모 시설을 효과적으로 활용 한다면, 도시 유역에서 강우시 발생하는 초기세척효과에 의한 비점오염 형태의 오염물질 유입을 차단해 오염물질 부하를 저감하는데 효과적으로 활용 될 수 있을 것으로 판단되며, 나아가 도서 지역내 용수공급을 위한 소규모 재이용 시설로도 활용 가치가 있을 것으로 판단된다.

• Membrane and Water Treatment
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• 제11권1호
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• pp.49-57
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• 2020

The effect of Combined Sewer Overflow on the river system was investigated throughout three preliminary field tests and three main ones. As a result of the study, Combined Sewer Overflow did not affect water qualities on the main stream since the concentration of the main stream did not significantly changed during rainfall events although the water quality of tributaries has rapidly deteriorated due to the influence of the Combined Sewer Overflow during rainfall events. The main cause of the result is that the flow rate of the tributaries is considerably lower than that of the main stream, so that the tributaries with deteriorated water quality during rainfall events did not significantly affect the quality of the actual main stream. Therefore, the water quality of the Kumho River is more affected by the wastewater treatment facilities that discharges water continuously to the main stream than pollutants from non-point pollution sources during rainfall events. As a result, managements for discharges from wastewater treatment facilities should be strengthened in order to improve the water quality of the river.

• 상하수도학회지
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• 제33권3호
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• pp.177-190
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• 2019

The purpose of this study was to analyze the effects of sewerage facilities through I/I analysis by rainfall by selecting areas where storm overflow diverging chamber is remained due to the non-maintenance drainage equipment when the sewerage system was reconstructed as a separate sewer system. Research has shown that wet weather flow(WWF) increased from 106.2% to 154.8% compared to dry weather flow(DWF) in intercepting sewers, and that the WWF increased from 122.4% to 257.6% in comparison to DWF in storm overflow diverging chamber. As a result, owing to storm overflow diverging chamber of partially separate sewer system with untreated tributary of sewage treatment plant, rainfall-derived infiltration/inflow(RDII) has been analyzed 2.7 times higher than the areas without storm overflow diverging chamber. Meanwhile, infiltration quantity of this study area was relatively higher than that of other study areas. Therefore, it is necessary to reduce infiltration quantity through sewer pipe maintenance nearby river. Drainage equipment maintenance should be performed not to operate storm overflow diverging chamber in order to handle the appropriate sewage treatment plant capacity for rainfall because it is also expected that RDII due to rain will occur after maintenance. In conclusion, it is necessary to recognize aRDII(allowance of rainfall-derived infiltration/inflow) and to be reflected it on sewage treatment plant capacity because aRDII can occur even after maintenance to the complete separate sewer system.

• 한국물환경학회지
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• 제26권6호
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• pp.1008-1015
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• 2010

Discharged pollution load is varied as rainfall changes in the area with combined sewer system. Changes in discharged pollution load are directly related with those of sewer transfer flow. Therefore, it is important to identify the pattern of sewer transfer flow for the analysis of changes in discharged pollution load. This study reviewed the type of distribution of sewer transfer flow for 17 sewage treatment plants and developed simple formular to estimate sewer transfer flow as rainfall changes. 11 facilities showed to have some relation with rainfall in the change of sewer transfer flow but 6 facilities to have no relation. Relationships between rainfall amount and sewer transfer flow showed that 6 facilities out of 11 had relatively strong relationships above R2=0.5, which were considered to be affected directly by rainfall changes. The formular which explain the relationship between rainfall and sewer transfer flow can be applied in the analysis of rainfall effects on discharged pollution load, therefore, the more appropriate evaluation will be done.

• 대한환경공학회지
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• 제37권2호
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• pp.126-135
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• 2015

도시지역의 소하천은 불투수 면적의 증가 및 우수관거의 발달로 인해 유역의 오염물질 및 강우 유출수의 유달률이 증가한 반면 비강우시에 현저하게 유량이 감소되어 하천환경에 심각한 문제를 나타내고 있다. 본 연구에서는 도시 하천의 유량과 수질 문제를 저감하기 위해 개발된 초기강우 저류 및 처리시설을 효율적으로 운영하기 위해 SWMM 도시유역모델 적용 결과와 자동모니터링 시스템을 이용하는 종합관리시스템을 개발하였다. 본 연구의 대상 지역인 관평천 유역의 대부분의 강우사상에서 오염물질은 초기 4시간의 강우 유출수에 집중되어 있는 것으로 관찰되었으며 이는 처리시설의 용량 결정에 있어 가장 중요한 인자로 작용한다. 본 시험 유역에서 유역모델인 SWMM을 이용하여 계산한 결과 처리시설에서 수용할 수 있는 초기우수 유출량은 약 6 mm의 누적강우량으로 산정되었으며 이는 대상지역에서 발생하는 대부분의 소규모 강우에 대해 처리가 가능하다는 것을 의미한다. 본 연구 결과는 강우-유출 모델과 연계한 초기우수 처리시설 운영을 위한 가이드라인을 제시하고 있으며, 하천 수질 모델과 연결할 경우 유입하천에 미치는 영향을 사전에 예측할 수 있으며, 유역의 조건과 연계하여 도시하천의 유역연계 종합 수질관리를 위한 중요한 자료를 제공할 수 있을 것이다.

• 한국물환경학회지
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• 제22권4호
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• pp.666-671
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• 2006

Effects of a rainfall event (July 28, 2005) on the hydrochemical characteristics of the Jungrang river, the biggest tributary of the Han river, was investigated. Significant spatial variations in the hydrochemical characteristics were observed. At JR2 location, concentrations of T-N and T-P were relatively low indicating occurrence of active oxidation in the stepped drop structure. At JR3 location, concentrations of Na, K, Cl, $NH_4-N$ and EC were elevated suggesting increased discharge from the nearby waste-water treatment plant and tributaries. The rain event diluted major dissolved ion concentrations in the river by 12~52%. The $NO_3-N$ levels were preserved during the rain then increased about twofold after rainfall, suggesting increased discharge of nitrate-contaminated groundwater. Heavy metals including Cd, Co, Cr, Cu and Pb were not detected in all water samples and the leachates from surface sediment samples. Concentrations of Fe, Mn, Al and Zn were below the Korean Drinking Water Guideline. Results of this study suggested that establishment of water-quality monitoring protocols describing temporal and spatial variations in parameters sensitive to rainfall events, relatively steady factors, and contaminant sources is required.

• Membrane and Water Treatment
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• 제10권1호
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• pp.99-104
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• 2019

In Korea, nonpoint pollutants have a significant effect on rivers' water quality, and they are discharged in very different ways depending on rainfall events. Therefore, preparing an optimal countermeasure against nonpoint pollutants requires much monitoring. The present study was conducted to help prepare a method for installing an automatic nonpoint pollutant measurement system for the cost-effective monitoring of the effect of nonpoint pollutants on rivers. In the present study, monitoring was performed at six sites of a river passing through an urban area with a basin area of $454.3km^2$. The results showed that monitoring could be performed for a relatively long time interval in the upstream and downstream regions, which are mainly comprised of forests, regardless of the rainfall amount. On the contrary, in the urban region, the monitoring had to be performed at a relatively short time interval each time when the rainfall intensity changed. This was because the flow rate was significantly dependent on the rainfall's intensity. The appropriate sites for installing an automatic measurement system were found to be a site before entering the urban region, a site after passing through the urban region, and the end of a river where the effects of nonpoint pollutant sources can be well-decided. The analysis also showed that the monitoring time should be longer for the rainfall events of a higher rainfall class and for the sites closer to the river end. This is because the rainfall runoff has a longer effect on the river. However, the effect of nonpoint pollutant sources was not significantly different between the upstream and the downstream in the cases of rainfall events over 100 mm.

• 한국환경복원기술학회지
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• 제4권3호
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• pp.55-65
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• 2001

The hydrological cycle system in the city is generally characterized by quick runoff, bad infiltration, low evaporation rate, and so on. It is caused by sealing greens up with pavements. Also, there are lots of contradictory environmental problems, such as inundation, the lack of underground water and dryness in the city, caused by the urban drainage system which is mostly focused on the quick draining off rainfall. In addition, the technique joining rain and sewage, which has more dangers of inundation, occupies 66% between two Korean drainage systems which consist of joining and dividing system. There has been some need to convert the present drainage system into the environmentally friendly hydrological cycle system. This is a theoretical study to examine some foreign cases and suggested applicable methods in our country, focusing on the environmentalyl friendly system of rainfall drainage. The precipitation treatment system can be made up of some possible phases choosing from premanagement, utilization, infiltration, retention, and inducement phases. Therefore, this study mostly focused on infiltration, retention, and inducement phases. It is necessary to suggest the multifunctional utilization of outdoor spaces, especially applying in new constructing and re-constructing residential estates.

• 한국물환경학회지
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• 제28권2호
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• pp.285-291
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• 2012

Generally, the rainfall and the influent of wastewater treatment plants (WWTPs) have strong relationship at the case of combined sewers. With the fact that the influent variations in terms of quantity and sewage quality is the most common and significant disturbance, the impact factor to the characteristics of sewage should be searched for. In this paper, the relationship between weather conditions such as humidity, temperature and rainfall and influent flowrate and contaminant concentration was analysed using factor analysis. Additionally, 3 influent types were deduced using cluster analysis and the distributions of operational variables were compared to the each groups by one-way ANOVA. The applied dataset were clustered to three groups that have the similar weather and influent conditions. These different conditions can cause the different operating conditions at WWTPs. That is, the Group 1 is for the condition with high humidity and rainfall, so DO concentration in the reactor was very high but MLSS concentration was very low because of too large flowrate. However, the Group 3 is classified to the case having low humidity, temperature, and rainfall, therefore, the SRT was the longest and the SVI was the highest due to the worst settleability in the winter for a year.

• 상하수도학회지
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• 제23권5호
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• pp.557-564
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• 2009

A combined sewer system can quickly drain both storm water and sewage, improve the living environment and resolve flood measures. A combined sewer system is much superior to separate sewer system in reduction of the non-point source pollutant load. However, during rainfall. it is impossible in time, space and economic terms to cope with the entire volume of storm water. A sewage system that exceeds the capacity of the sewer facilities drain into the river mixed with storm-water. In addition, high concentration of CSOs by first-flush increase pollution load and reduce treatment efficiency in sewage treatment plant. The aim of this study was to develope a processing unit for the removal of high CSOs concentrations in relation to water quality during rainfall events in a combined sewer. The most suitable operational design for processing facilities under various conditions was also determined. With a designed discharge of 19.89 m/min, the removal efficiency was good, without excessive overflow, but it was less effective in relation to underflow, and decreased with decreasing particle size and specific gravity. It was necessary to lessen radius of vortex separator for increasing inlet velocity in optimum range for efficient performance, and removal efficiency was considered to high because of rotation increases through enlargement of comparing height of vortex separator in diameter. By distribution of influent particle size, the actual turbulent flow and experimental results was a little different from the theoretical removal efficiency due to turbulent effect in device.