• 상하수도학회지
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• 제20권4호
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• pp.627-635
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• 2006

Combined sewer overflow (CSOs) is a primary diffuse source degrading water quality of urban streams. In this study, CSOs caused by 5 different rainfall events at an urban watershed located in Daejeon city were monitored for the indicator microorganism concentrations. Event mean concentration (EMC) of the indicator microorganisms were: total coliform = $2.46{\times}10^6CFU/100mL$; fecal coliform = $1.01{\times}10^6CFU/100mL$; E.coli = $5.20{\times}10^5CFU/100mL$; and Fecal Streptococci = $6.08{\times}10^5CFU/100mL$. In addition, coliform concentrations were well correlated with suspended solid concentrations and the first flush effects were identified. Settling tests were carried out to estimate removal rate of indicator organisms by sedimentation from CSOs. As microorganisms are discharged in association with suspended solid, ten minutes of settlement can lower 44% of indicator microorganism leading.

• 한국물환경학회지
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• 제31권4호
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• pp.428-435
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• 2015

This study was carried out to evaluate the performance of a inflow controller for the control of combined sewer overflows (CSOs). Because of the inflow controller could be adjusted manually by predicting the maximum amount of peak flow, the mechanical adjustment of this controller was higher than the existing fixed-type controller in field application. Standardizing the relationship between the flow and the clearance and angle of an inlet cover plate on the inflow conditions can selected to the optimum conditions for the on-site. It was concluded that BOD pollutant loading at the region in which inflow controller was installed had shown the removal efficiency rate of 42%.

• Environmental Engineering Research
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• 제10권2호
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• pp.62-70
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• 2005

Pollution loading of Combined Sewer Overflows (CSOs) is frequently over the capacity of a wastewater treatment plant (WWTP) receiving the water. The objectives of this study are to investigate water quality of CSOs in Anmyun-ueup, Tean province and to apply Storm Water Management Model to predict flow rate and water quality of the CSOs. The capacity of a local WWTP was also estimated according to rainfall duration and intensity. Eleven water quality parameters were analyzed to characterize overflows. SWMM model was applied to predict the flow rate and pollutant load of CSOs during rain event. Overall, profile of the flow and pollutant load predicted by the model well followed the observed data. Based on model prediction and observed data, CSOs frequently occurs in the study area, even with light precipitation or short rainfall duration. Model analysis also indicated that the local WWTP’s capacity was short to cover the CSOs.

• 한국물환경학회지
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• 제22권6호
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• pp.1075-1081
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• 2006

In this research, mortality rates of pathogen indicator microorganisms discharged from various point sources and diffuse sources in urban area were measured. Water samples were taken at domestic sewer, combined sewer overflow, effluent from a wastewater treatment plant, urban river, and sediment of an urban river. Mortality rates of indicator microorganisms in domestic sewer estimated by assuming the first order kinetics at $20^{\circ}C$ were as follows: total coliform = 0.092/day, fecal coliform = 0.185/day, E. coli = 0.252/day, and fecal streptococci = 0.281/day. Sensitivity of mortality rates of total coliform on temperature was estimated as $K_{temp}=K_{20}{\times}1.162^{(temp-20)}$ for the range of $10-20^{\circ}C$. Mortality rates due to sunlight were measured as 1.22-1.59/day while mortality rate due to settling for 40 min were estimated as $9.21{\times}10^3-20.0{\times}10^3/day$.

• 상하수도학회지
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• 제25권6호
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• pp.935-947
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• 2011

In the era of climate change, the feasibility of a 'multi-functional storage facility' was evaluated in terms of various key performance indices such as flooding prevention effects, urban pollution reduction effects, and rainwater harvesting effects. As a result, the Korea Ministry of Environment introduced a new concept of 'multi-functional storage facility' for sewer flooding prevention and urban non-point pollution reduction. Prior to introducing these infrastructure (a large underground storage facility), the more details were needed to be examined carefully in all of technical aspects of construction and management. It was also well known that the validity of installation of 'multi-functional storage facility' was sometimes weakened because of a low B/C ratio.

• 대한환경공학회지
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• 제30권1호
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• pp.9-14
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• 2008

• 한국물환경학회지
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• 제36권3호
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• pp.206-219
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• 2020

As urbanization and impermeable areas have increased, stormwater and non-point pollutants entering the stream have increased. Additionally, in the case of the old town comprising a combined sewer pipe system, there is a problem of stream water pollution caused by the combined sewer overflow. To resolve this problem, many cities globally are pursuing an environmentally friendly low impact development strategy that can infiltrate, evaporate, and store rainwater. This study analyzed the expected effects and efficiency when the LID facility was installed as a measure to improve hydrologic cycle and water quality in the Oncheon stream in Busan. The EPA-SWMM, previously calibrated for hydrological and water quality parameters, was used, and standard parameters of the LID facilities supported by the EPA-SWMM were set. Benchmarking the green infrastructure plan in New York City, USA, has created various installation scenarios for the LID facilities in the Oncheon stream drainage area. The installation and maintenance cost of the LID facility for scenarios were estimated, and the effect of each LID facility was analyzed through a long-term EPA-SWMM simulation. Among the applied LID facilities, the infiltration trench showed the best effect, and the bio-retention cell and permeable pavement system followed. Conversely, in terms of cost-efficiency, the permeable pavement systems showed the best efficiency, followed by the infiltration trenches and bio-retention cells.

• 상하수도학회지
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• 제25권6호
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• pp.949-957
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• 2011

This aim of study was to investigate the characteristics of discharge of pollutants as well as the correlation between flow rate and water quality constituents in a combined sewer system according to the characteristics of rainfall. For the loading rates for each pollutant, the median concentrations of all pollutants except T-N was increased when a CSO took place. The loading rates of BOD, COD, SS, T-N, T-P, Cu and Zn at the CSOs were 328-1255, 25-129, 83-2009, 4-12, 14-51, 5-11 and 5-13 times higher than the DWF (Dry Whether Flow), respectively. Especially, SS loading rate was found to be highest in all pollutants. On the other hand, the range of the first flush coefficient, b for water quality constituents such as BOD, COD, SS, T-N, T-P, Cu and Zn were 0.537-0.878, 0.589-0.888, 0.516-1.062, 0.852-1.031, 0.649-0.954, 0.975-1.015 and 0.900-1.114, respectively. In term of correlation between flow rate and pollutant concentrations, SS concentration was highly correlated to flow rate. However, there was an inverse correlation between EC (Electrical Conductivity) and flow rate because of the high dilution of flow rate. In case of correlation between pollutants, there was a high correlation between SS and T-P.

• 한국환경과학회지
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• 제19권6호
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• pp.747-753
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• 2010

It follows in quality and sewage exclusion method of the investigation objective sector and the Combined Sewer Overflows which is suitable in regional characteristics and the confluence area against the rainfall initially a flow and the medulla and measurement - it analyzes the initial rainfall outflow possibility control plan which is suitable in the domestic actual condition and it proposes the monitor ring plan for the long-term flow and pollution load data accumulation. From the research which it sees the Infiltration water/Influent water and CSOs investigation it passes by the phase of hazard chain and Namwon right time 4 it does not hold reverse under selecting, Measurement it used the hazard automatic flow joint seal Sigma 910 machine and in case 15 minute interval of the I/I, it measured a flow at case 5, 15 minute standing of the CSOs. The water quality investigation for the water leakage investigation of the I/I and the sewage from the point which is identical with flow measurement during on-the-spot inspection duration against 6 items which include the BOD sampling and an analysis, when the rainfall analysis for CSOs fundamental investigation analyzed against 18 items which include the BOD sampling. Consequently, for the optimum interpretation invasion water / inflow water of the this investigation area day average the lowest flow - water quality assessment veterinarian optimum interpretation hazard average per day - lowest flow - it averages a medulla evaluation law department one lowest flow evaluation technique and it selects, it presentation collectively from here it gets, position result with base flow analysis of invasion water / inflow water.

• 한국수자원학회논문집
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• 제48권9호
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• pp.695-709
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• 2015

지속적인 개발과 도시화로 인하여 하천으로 유입되는 비점오염원의 비율 역시 점차 증가하는 추세이며 비점오염원이 수질악화에 미치는 영향은 점점 더 커지고 있다. 하천의 수질오염을 발생시키는 비점오염원 해결방안을 모색하고 있지만 도시화에 따른 수문현상변동 및 자연현상과 관련된 문제라 연구에 어려움이 많다. 본 연구에서는 기존의 총량원단위법과 달리 유역의강우 및 도시화 특성과 처리장 운영자료를 활용하여 차별화된 비점오염원 산정 방법을 제시하였다. 하수처리장의 배수구역 내 관거시스템을 합류식으로 가정하여 강우 시 하수처리장의 배수구역별 비점 발생형태는 하수처리장 강우유 입량, 하수처리장 우회유량(bypass) 및 하천토구의 CSO의 3가지로 크게 구분하여 적용함으로써 오염부하량을 산정함으로써 오염총량 단위유역 및 하수처리구역의 관리를 위한 비교자료로 활용 가능할 것으로 판단된다.