• 상하수도학회지
• /
• 제20권4호
• /
• pp.585-594
• /
• 2006

This study focused on the causes of fish kills and its prevention methods in Yudeung Stream, Daejeon, Korea. Intense field data, continuous water quality monitoring system and water quality modeling were applied to analyze the causes. Pollutant can be delivered to urban streams by surface runoff and combined sewer overflows in rainfall events. However, water quality analysis and water quality modeling results indicate that the abrupt fish kills in the Yudeung stream seems to be caused by combined effect of DO depletion, increase in turbidity and other toxic material. Excessive fish population in the study area may harm the aesthetic value of the stream and also has greater potential for massive fish kills. It is suggested to implement methods to reduce delivery of pollutants to the stream not only to prevent fish kills but also to keep balance of ecosystem including human uses. Frequent clean up of the urban surface and CSO, installation of detention basin will be helpful. In the long run, it seems combined sewer system has be replaced with separate sewer system for more effective pollutant removal in the urban area.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2005년도 학술발표회 논문집
• /
• pp.1199-1203
• /
• 2005

Combined sewer overflows(CSOs) are themselves a significant source of water pollution. Therefore, the control of urban drainage for CSOs reduction and receiving water quality protection is needed. Examples in combined sewer systems include downstream storage facilities that detain runoff during periods of high flow and allow the detained water to be conveyed by an interceptor sewer to a centralized treatment plant during periods of low flow. The design of such facilities as stormwater detention storage is highly dependant on the temporal variability of storage capacity available(which is influenced by the duration of interevent dry periods) as well as the infiltration capacity of soil and recovery of depression storage. As a result, a contiunous approach is required to adequately size such facilities. This study for the continuous long-term analysis of urban dranage system used analytical Probabilistic model based on derived probability distribution theory. As an alternative to the modeling of urban drainage system for planning or screening level analysis of runoff control alternatives, this model have evolved that offer much ease and flexibility in terms of computation while considering long-term meteorology. This study presented rainfall and runoff characteristics or the subject area using analytical Probabilistic model. Runoff characteristics manifasted the unique characteristics of the subject area with the infiltration capacity of soil and recovery of depression storage and was examined appropriately by sensitivity analysis. This study presented the average annual COSs and number of COSs when the interceptor capacity is in the range 3xDWF(dry weather flow). Also, calculated the average annual mass of pollutant lost in CSOs using Event Mean Concentration. Finally, this study presented a dicision of storage volume for CSOs reduction and water quality protection.

• 한국물환경학회지
• /
• 제23권4호
• /
• pp.490-497
• /
• 2007

A Combined sewer overflows (CSOs) are themselves a significant source of water pollution. Therefore, the control of urban drainage for CSOs reduction and receiving water quality protection is needed. Examples in combined sewer systems include downstream storage facilities that detain runoff during periods of high flow and allow the detained water to be conveyed by an interceptor sewer to a centralized treatment plant during periods of low flow. The design of such facilities as stormwater detention storage is highly dependant on the temporal variability of storage capacity available (which is influenced by the duration of interevent dry periods) as well as the infiltration capacity of soil and recovery of depression storage. As a result, a continuous approach is required to adequately size such facilities. This study for the continuous long-term analysis of urban drainage system used analytical probabilistic model based on derived probability distribution theory. As an alternative to the modeling of urban drainage system for planning or screening level analysis of runoff control alternatives, this model have evolved that offer much ease and flexibility in terms of computation while considering long-term meteorology. This study presented rainfall and runoff characteristics of the subject area using analytical probabilistic model. This study presented the average annual COSs and number of COSs when the interceptor capacity is in the range $3{\times}DWF$ (dry weather flow). Also, calculated the average annual mass of pollutant lost in CSOs using Event Mean Concentration. Finally, this study presented a decision of storage volume for CSOs reduction and water quality protection.

• 상하수도학회지
• /
• 제25권6호
• /
• pp.959-970
• /
• 2011

The frequent occurrence of sewer flooding and the intermittent discharge of non-point pollutions into the receiving water body are emerging issues recently due to the climate change and urbanization. These problems might be solved by introducing a multifunctional storage facility. Unlike a single-purpose storage facility, a multi-purpose storage facility should be operated at an instant to meet for flood prevention, reduction of non-point pollution and/or rainwater reuse. Considering various operational combinations it is suggested that prevention of sewer flooding coupled with reduction of non-point pollution is the most effective operational strategy for a multi-functional storage facility.

• 한국산학기술학회논문지
• /
• 제9권1호
• /
• pp.129-135
• /
• 2008

하천으로 유입되는 합류식월류수(Combined Sewer Overflows, CSOs)는 하천의 수질 오염에 영향을 끼치게 되며 월류량은 차집관거의 설계용량에 따라서 결정되어진다. 따라서 차집관거의 기준 용량은 강우 유출의 특성 및 수질을 고려하여 합리적으로 결정되어야한다. 그러나 국내의 차집관거 기준 용량은 일괄적으로 시간최대오수량의 3배로 책정되어있으며, 강우-유출의 특성을 고려하지 않은 채 모든 지역에 대하여 균일하게 적용되어왔다. 따라서 본 연구에서는 강우유출 특성을 고려하여 강우 데이터에 대한 통계적 분석을 통하여 차집관거의 기준 용량을 결정하기 위한 기준 강우를 산정하였다. 서울지역의 평균개념의 확률강우량을 통하여 산정된 기준강우의 지속시간은 4hr이며 강우량은 재현기간 1.5년에 해당하는 6.76mm로 산정되었다. 또한 산정된 기준 강우를 적용하여 강우유출 특성 분석은 SWMM을 이용하였으며 이를 통하여 CSOs를 계산하였다.

• 한국수자원학회논문집
• /
• 제41권9호
• /
• pp.885-894
• /
• 2008

합류식 관거 내 고형물의 퇴적으로 인해 통수능이 감소하여 여름철 장마시 국지적인 침수가 발생하며 이로 인해 관거 내 퇴적을 더욱 초래할 수가 있다. 이와 같은 문제를 해결하고 관거의 적절한 유지관리를 위해서는 지표면으로 부터의 고형물 부하량 산정 및 강우로 인해 지표 퇴적 고형물이 관거 내로 유입되어 퇴적되는 양을 산정할 필요가 있으나 많은 비용과 노력이 수반되어야 한다. 따라서 본 연구에서는 지표면에서의 고형물 부하량 산정기법을 우리나라 군자배수유역에 적용하여 분석하고, 이를 바탕으로 MOUSE모형을 적용한 결과를 이용하여 관거 내 고형물 퇴적량을 산정하기 위한 회귀식을 개발하고 적용성을 검토하였다. 분석결과 유역 내 관거에서의 퇴적고형물 관측자료가 구비되어 있지 않아 실질적으로 비교하기는 곤란하지만, MOUSE 모형결과 및 타 유역에서의 적용결과로 볼 때 적용성이 있다고 판단되며, 합류식 관거 유지관리에 개발된 산정식을 유용하게 이용할 수 있으리라 본다.

• 수도
• /
• 통권69호
• /
• pp.47-58
• /
• 1994

• 한국물환경학회지
• /
• 제36권5호
• /
• pp.423-430
• /
• 2020

To improve the low treatment efficiency of sewage treatment plants, the separated sewer system must be maintained to provide an adequate flow rate and quality of the sewage under the effect of inflow. In this study, data from five locations of Namsuk, Dukgok1, Dukgok2, Kanggu, and Opo were used to conservatively calculate the inflow water volume. The sewer flow and rainfall data were collected in 2017. The factors in the standard method used to calculate the inflow of the combined sewer pipes including "rainy days", "rainfall impact period", and "period for basal sewer" were defined as 3 mm/day, continuous rain for two days, and two weeks prior to the inflow generation, respectively. "Rainy days", "rainfall impact period", and "period for basal sewer" were conservatively adjusted to 5 mm/day, continuous rain for five days, and three weeks prior to the inflow generation, respectively. As a results of the adjustment, the linearity (r²) was improved except for in Dukgok1. This implies that the conservative adjustment made in this study could improve the management quality of sewer pipes. Also, the linear correlation coefficient (a_i) between inflow and rainfall showed a large difference between the target locations, which can be another monitoring factor affecting the quality of sewer pipes. To improve the correlation based on the individual characteristics of the locations in Korea, the automatic algorithm for the inflow calculation should be developed by innovative intellectual technologies for application to the entire national area.

• 한국방재학회 논문집
• /
• 제7권4호
• /
• pp.107-113
• /
• 2007

The Kuem-River, one of the largest rivers in Korea, is the primary water source for more than 4 million people in Kongju city and surrounding area. To study the effect of stormwater runoff to CSOs, twelve monitoring sites were selected in two large cities (City of Kongju and City of Buyeo) near the Kuem-River. Monitoring was reformed by collecting grab samples, measuring flow rates during dry and wet seasons during over two rainy seasons. Generally the flow rate of wastewater in combined sewers was rapidly decreased after 23:00 P.M. and gradually increased from 06:30 A.M. in all sites during the dry season. The concentrations of pollutant increase approximately 5 to 7 fold for TSS and 1.5 to 2.5 fold for BOD during the rainy season. Monitoring and statistical analysis show that the groundwater contributes on sewage volume increase (average 25-45% more) during dry periods and the stormwater runoff contributes approximately 51-72% increase during rainy periods. Generally the concentrations of combined sewage were more polluted during the first flush period than after the first flush during a storm event.

• 상하수도학회지
• /
• 제24권2호
• /
• pp.231-236
• /
• 2010

A compressible media filtration process with synthetic fiber media was studied for combined sewer overflows (CSOs) treatment. Since the operation performance of fiber media filtration was dependent on the pattern of CSOs, the flow rate of CSOs was investigated and it was characterized by a big fluctuation. Thus, in this study, the fiber media filtration process was tested with wide range of filtration velocity. The removal efficiency was proportion to the increase in compressibility. As the filtration velocity was increased, the treatment efficiency was decreased and consequently leveled off when the velocity exceeded 750 $m^3/m^2$/d. An exponential equation was introduced to express the relationship between the removal efficiency and up-flow velocity. At columm test, six repetition of filtration and backwash cycle did not after the filtering velocity under the constant pressure condition.