• 한국습지학회지
• /
• 제21권3호
• /
• pp.224-235
• /
• 2019

급격한 도시화는 도시 하천에 크게 세 가지 문제점을 야기하고 있다. 첫 번째 문제는 불투수지역의 증가에 따른 강우의 토양 침투량 감소이다. 토양 침투량 감소는 도시하천의 물순환에 심각한 왜곡을 일으키게 된다. 두 번째 문제는 도시적 토지이용에 따른 비점오염물질의 증가이며, 세 번째 문제는 구도심에서의 합류식 하수관거 월류수이다. 비점오염물질의 증가 및 합류식 하수관거 월류수는 물순환 왜곡과 맞물려서 도시하천 수질오염을 가중시키게 된다. 본 연구에서는 이러한 세 가지 문제점에 대한 해결방안을 제시하고자 부산 온천천 유역을 대상으로 EPA SWMM을 구성하였으며, 미국 뉴욕시에서 실제로 시행중인 사업을 벤치마킹하여 생태저류지 설치 사업을 계획하였다. 사업 시나리오별로 물순환 개선효과와 비점오염 및 합류식 하수관거 월류수의 저감량이 요구되는 예산과 함께 분석되었다.

• 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
• /
• 제27권6호
• /
• pp.711-721
• /
• 2013

Optimal operation of a combined sewer network with distributed storage facilities aims to use the whole retention capacity of all reservoirs efficiently before overflows take place somewhere in the considered network system. An efficient real-time network control (RTNC) strategy has been emerging as an attractive approach for reducing substantially the overflows from a sewer network compared to the conventional fixed or manually adjusted gate setting method, but the related concrete framework for RTC development has not been throughly introduced so far. The main goal of this study is to give a detailed description of the RTNC systems via reviewing several guidelines published abroad, and finally to suggest methods for the proper application of RTNC on distributed storage facilities. Especially, this study is focused on emphasizing the importance of hierarchical structure of RTNC system that consists of three control layers (management, global control and local control). Further, with regard to the global control layer which is responsible for the central overall network control, the wide-ranging details of two components (adaption and optimization layers) are also presented. This study can provide the valuable basis for the RTNC implementation in the particular sewer network with distributed multiple storage facilities.

• 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.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2005년도 학술발표회(1)
• /
• pp.255-256
• /
• 2005

• Environmental Engineering Research
• /
• 제18권2호
• /
• pp.71-75
• /
• 2013

This study is to evaluate the effects of the separation wall on the sediment quality and quantity in a combined sewer, by surveying the sewer overflow and sediments during a rainfall. Since the separation wall installed in the combined sewer separates the rainfall and the sewage, the flow rate of the sewage is increased, and the amount of the sediment deposited on the sewer is decreased. One sampling point was the outfall of Daesacheon with a separation wall, and the other was the outfall of Gwaryecheon without a separation wall, in Daejeon metropolitan city. The maximum control of the biochemical oxygen demand (BOD) overflow load was more than 38% in the Daesacheon point with the separation wall, during a rainfall of 0.11 mm/hr. The maximum control of the BOD overflow load was 24% in Gwaryecheon without a separation wall, during a rainfall of 1.0 mm/hr. According to the survey results of the sediment in the sewer, the discharged sediment deposited on the sewer in Gwaryecheon point was about 23% to 28% of the total suspended solid during the rainfall. In addition, the average velocity of sewage in the presence of sediment was about 0.30 m/s, and if the separation wall is installed, it was expected to be about 1.01 m/s, that is 3.4 times more than the same conditions, resulting in the reduction of the sediment deposit.

• 대한환경공학회지
• /
• 제35권11호
• /
• pp.785-794
• /
• 2013

합류식하수관로시스템에서 강우시 유출수는 관로내 퇴적물과 지표면 세척효과에 의한 오염물질 등이 혼합되어 하천으로 방류되기 때문에 방류수계에 화학적 물리적 생물학적으로 상당한 문제를 야기하지만, 현재 국내에서는 CSOs의 오염 부하량 관리기준을 결정함에 있어 통일된 방법론이 부재한 실정이다. 이에 따라 본 연구에서는 우수유출모형을 활용한 장기간 CSOs 유량-수질모의를 통하여 CSOs의 오염부하량 저감목표를 설정하고자 한다. 이를 위하여 국내외 CSOs 관리기준을 검토하였으며, 그 결과 연간 총 월류부하량 및 발생빈도를 총 2단계로 구분하여 관리하고, 1단계에서는 60%, 2단계에서는 85%를 저감하는 것을 목표로 설정하였다. 도출된 저감 목표 기준을 대상지역에 적용하여 장기간(최소 10년간)의 CSOs 발생 모의를 바탕으로 분석한 결과, BOD 월류부하량 저감목표는 1단계 1,123 kg, 2단계 2,374 kg이었으며, 목표 달성을 위해 대응해야 할월류량은 1단계 $11,685m^3$, 2단계 $24,701m^3$으로 나타났다.

• 상하수도학회지
• /
• 제26권2호
• /
• pp.295-302
• /
• 2012

The coagulation of combined sewer overflows ($CSO_{s}$) was investigated by jar-testing with several commercial coagulants. $CSO_{s}$ sample showed different characteristics of coagulation from secondary wastewater with three common coagulants, aluminum sulfate, ferric chloride and polyaluminum chloride (PACl). Jar-tests showed that relatively wide range of optimal SS and T-P removal yielded with alum and ferric chloride compared with cationic polymers, though efficient SS and T-P removal can be achieved with all three coagulants. The decrease of pH was caused by the increase in dosage of aluminum sulfate, ferric chloride and PACl as coagulants. The pH was changed from 7.0 to 4.7 with the dosages of ferric chloride 25 mL/L. Aluminum sulfate revealed pH of 5.0 and PACl was highest pH of 5.4 after dosing of coagulants. The optimal pH to treat $CSO_{s}$ with aluminum sulfate were 6-6.5; with PACl 6-7, and with ferric chloride higher than 7.

• 한국산학기술학회논문지
• /
• 제15권5호
• /
• pp.3159-3168
• /
• 2014

비점오염원 관리를 위한 독립호우의 결정은 월류수 처리시설의 설계에서 필수적이다. 비점오염원의 관리를 위해서는 총량을 결정해야만 하는데 이를 위해서는 결정된 독립호우에 의해 1회 평균강우량, 평균강우강도, 평균지속시간 등의 강우특성의 분석이 실시되어야만 한다. 독립호우의 결정은 무강우 지속시간의 산정(Interevent Time Definition, IETD)에 따라 분리할 수 있으며 이를 결정하기 위한 기존의 분석방법에는 자기상관 분석, 변동계수 분석, 연강우 평균발생횟수 분석 등이 있다. 본 연구에서는 기존의 IETD 분석방법에 따라 무강우시간을 산정한 후 방법별 문제점을 고찰하고 새로운 IETD 결정방법으로 지수함수 검정방법을 제안하였다. 또한, 검정방법을 통하여 결과값의 적절성을 검토하였다.