• 제목/요약/키워드: First flush effect

검색결과 44건 처리시간 0.03초

합류식 하수관거 월류수 저장 시설에 대한 효과 - 강우시 합류식 하수관거에서의 오염물질 유출특성 분석 (Effect for CSOs Storage Construction - Analysis of Storm Water Run-off Characteristics in combined sewer system)

  • 박진규;이남훈;김해룡;이웅;이채영
    • 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.

주차장 및 교량지역의 강우유출수내 비점오염물질의 특성 비교 및 동적 EMCs (Characteristics of Washed-off Pollutants and Dynamic EMCs in a Parking Lot and a Bridge during Storms)

  • 김이형;이선하
    • 한국물환경학회지
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    • 제21권3호
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    • pp.248-255
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    • 2005
  • Since the water quality of drinking water sources has been recognized as a big issue, the ministry of Environment in Korea is designing the total maximum daily load (TMDL) program for 4 major large rivers. The TMDL program can be successfully performed as controling the nonpoint pollutants from watershed area near the river. Of the various landuses in nonpoint pollution, parking lots and bridges are stormwater intensive landuses because of high imperviousness and high pollutant mass emissions from vehicular activities. Vehicle emissions from those areas include different pollutants such as heavy metals, oil and grease and particulates from sources such as fuels, brake pad and tire wear, etc. Especially the pollutant washed-off from the landuses are directly affecting to the river water quality. Therefore this research was conducted to understand the magnitude and nature of the stormwater emissions with the goal of quantifying stormwater pollutant concentrations and mass emission rates of pollutants from parking lot and bridges in Korea. In Kongju city areas, two monitoring sites were equipped with an automatic rainfall gages and an automatic flow meter for accumulating the useful data such as rainfall, water quality and runoff flow. This manuscripts will show the concentration changes during storm duration and EMCs to characterize the concentration profiles in different land uses. Also the first flush criteria will be suggested using dynamic EMCs. The definition of dynamic EMC is a new approach explaining the relationship of EMC and first flush effect.

Effect of Chip Spacing in a Multichip Module on the Heat Transfer for Paraffin Slurry Flow

  • Choi, Min-Goo;Cho, Keum-Nam
    • Journal of Mechanical Science and Technology
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    • 제14권9호
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    • pp.997-1004
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    • 2000
  • The experiments were conducted by using water and paraffin slurry to investigate the effect of a chip spacing in the multichip module on the cooling characteristics from an in-line $4{\times}3$ array of discrete heat sources which were flush mounted on the top wall of a channel. The experimental parameters were chip spacing in a multichip module, heat flux of simulated VLSI chip, mass fraction of paraffin slurry, and channel Reynolds number. The removable heat flux at the same chip surface temperature decreased as the chip spacing decreased at the first and fourth rows. The local heat transfer coefficients for the paraffin slurry were larger than those for water, and the chip spacing on the local heat transfer coefficients for paraffin slurry influenced less than that for water. The enhancement factor for paraffin slurry showed the largest value at a mass fraction of 5% regardless of the chip spacing, and the enhancement factors increased as the chip spacing decreased. This means that the paraffin slurry is more effective than water for cooling of the highly integrated multichip module.

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Analysis to Select Filter Media and The Treatment Effect of Non-point Pollution Source in Road Runoff

  • Lee, Tae Goo;Han, Young Hae
    • KIEAE Journal
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    • 제14권3호
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    • pp.55-63
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    • 2014
  • This study selected and analyzed filter media that can be applied in non-point pollution reduction devices aimed at processing the source of pollution on site for road runoff that increases rapidly in rainfall-runoff in order to improve the water quality of urban areas. First, the factors that affect the quality of runoff caused by sources of non-point pollution include physical and social factors such as the usage of land around the area of water collection, type of pavement and movement of cars and people, as well as rainfall characteristics such as frequency, intensity, amount and duration of rainfall. Second, the purification tests of the filter media were processed for pH, BOD, COD and T-P, and the filter media showed to have initial purification effect at that items. However, the filter media showed to be very effective for the processing of SS, T-N, Zn and Cd from the beginning to the end. Third, for filter media, zeolite and vermiculite showed to be effective for processing SS, T-N, Zn and CD constantly, and composite filter media including zeolite showed to have strong processing effects. The authors conclude that this study can be applied to technical areas and policies aimed at reducing non-point pollution in urban areas and can also contribute to allowing eco-friendly management of rainfall as well as improvement of water quality.

Two-dimensional energy transmitting boundary in the time domain

  • Nakamura, Naohiro
    • Earthquakes and Structures
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    • 제3권2호
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    • pp.97-115
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    • 2012
  • The energy-transmitting boundary, which is used in the well-known finite element method (FEM) program FLUSH, is quite efficient for the earthquake response analysis of buildings considering soil-structure interaction. However, it is applicable only in the frequency domain. The author proposed methods for transforming frequency dependent impedance into the time domain, and studied the time domain transform of the boundary. In this paper, first, the estimation methods for both the halfspace condition under the bottom of the soil model and the pseudo three-dimensional effect were studied with the time domain transmitting boundary. Next, response behavior when using the boundary was studied in detail using a practical soil and building model. The response accuracy was compared with those using viscous boundary, and the boundary that considers the excavation force. Through these studies, the accuracy and efficiency of the proposed time domain transmitting boundary were confirmed.

강우에 의한 도로 비점오염원 유출 특성 (Runoff Characteristics of Non-Point Sources on the Stormwater)

  • 김석구;김영임;강성원;윤상린;김소정
    • 대한환경공학회지
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    • 제28권1호
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    • pp.104-110
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    • 2006
  • 도시화로 인해 증가하고 있는 불투수층은 강우시 지표면 유출수와 함께 유출되는 비점오염물질의 유출량을 증가시킨다. 비점오염원은 인위적인 조절이 어려운 기상, 지형 등의 영향을 받는 특성을 지니고 있어 제어가 어렵다. 따라서 비점오염원에 대한 기초적인 조사는 오염물질 유출 저감에 기여할 수 있을 것으로 판단되어 본 연구에서는 오염물질 유출특성과 유출입자의 입도분포를 조사하였다. 본 연구는 연구단지 내 주차장과 인접한 도로에서 진행되었으며, 오염물질의 평균 농도는 $SS\;26.8{\sim}126.4mg/L,\;COD_{Cr}\;15.3{\sim}117.7mg/L,\;TN\;0.07{\sim}5.16mg/L,\;TP\;0.06{\sim}0.49mg/L$, 중금속류 $0.00{\sim}0.29mg/L$의 범위를 나타냈다. 또한 강우에 따라 차이를 보이나 오염물질의 초기 세척효과가 나타났으며, SS와 오염물질의 유출은 $0.93{\sim}0.99$의 높은 상관관계를 나타냈다. 도로면 유출수의 입도 특성을 살펴본 결과, 기존 자료보다 미세한 것으로 관찰되었다.

농촌지역 비점오염물질의 유출 특성 (Runoff Characteristics of Non-point Pollutant Sources in an Agricultural Area Watershed)

  • 유광현;이건직;성진욱;김동섭;박제철
    • 생태와환경
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    • 제44권2호
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    • pp.178-186
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    • 2011
  • 본 연구는 강우 시 농촌지역에서 강우유출수와 함께 하천으로 유입되는 비점오염물질의 유출특성을 파악하기 위해 수행되었다. 유량의 증감에 따른 수질항목의 상관관계는 SS, T-P, $COD_{Mn}$, BOD, TN의 순으로 상관성이 높은 것으로 나타났고, 강우량, 강우강도, 선행무강우일수에 따라 다양한 유출 특성을 보였다. 분석된 결과를 바탕으로 EMC와 SMC를 산정한 결과 SS, T-P는 강우사상에 따라 높은 EMC 농도변화를 보였고 산술평균농도와 EMC를 비교하였는데 대체적으로 EMC가 더 높은 것으로 나타나 유량의 증감에 영향이 있는 것으로 나타났으나 T-N의 경우 영향이 없는 것으로 보였다. 또, 초기유출 특성을 살펴보면 강우 후반부의 강한 강우강도로 인해 초기세척 개념을 적용시키기 어려운 3차 이벤트와 강우량이 적고 강우강도도 약했던 5차 이벤트를 제외한 다른 이벤트에서 초기세척효과가 관찰되었고 SS > T-P > BOD > $COD_{Mn}$ > T-N 순으로 뚜렷하게 나타났다. 그리고 초기세척비율 계산 결과, 초기 유출수의 30%에 가장 많은 오염부하가 발생하고 대부분 입자형태 즉, SS, T-P의 유출이 뚜렷하므로 저류지를 통해 초기 강우유출수의 비점오염물질을 제거하는 것이 바람직하다고 판단된다. 본 연구를 통해 분석된 결과를 바탕으로 비점오염물질의 유출특성에 대한 다양한 데이터베이스를 구축하여 향후 비점오염원을 체계적으로 관리함으로써 하천 수질을 개선하려는 노력이 필요할 것으로 사료된다.

산업단지내 비점오염물질 처리를 위한 적정 저류조 용량 산정 및 처리효율 (Optimum Capacity of Retention Basin for Treating Nonpoint Pollutants and Its Removal Efficiency in Industrial Complex Areas)

  • 김이형;이병식;권수열
    • 한국습지학회지
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    • 제7권3호
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    • pp.75-85
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    • 2005
  • 산업단지 조성은 포장율의 증가를 의미하며, 다량의 비점오염물질이 강우시 유출되게 된다. 이러한 비점오염물질의 처리 및 저감을 위해서는 저류지 건설 등이 대안이 될 수 있기에 최근 환경부는 홍수조절용 우수저류조를 비점오염물질 처리용 저류조로의 전환을 꾀하고 있다. 2005년도에 비점오염원 관리 방안이 법제화됨으로써, 향후 신규개발 지역에서는 비점오염물질 관리를 위한 최적관리방안이 필수화 될 것이다. 본 연구지역의 토지이용은 산업단지 조성지역으로 제 1차 제조업 및 금속산업, 섬유 및 화학제품 제조업 등의 업종이 주를 이루고 있다. 산업단지 조성은 인근 수계에 심각한 비점오염물질 부하량을 증가시킨다. 따라서 본 연구는 산업단지에서의 비점오염물질 처리 및 저감을 위하여 저류지 또는 습지 조성을 위하여 추진되었으며, 비점오염물질 관리를 위한 적정 저류지 용량 산정은 강우량 해석, 유출량 해석 및 비점오염물질 유출해석 등을 통하여 적정 용량을 산정할 수 있다. 연구지역의 일 평년, 최근 10년간, 최근 2년간 및 5년간의 강우량 자료를 통계 분석한 결과 초기 강우현상을 고려하지 않을 경우 발생빈도 80% 이상의 강우에 대한 적정 강우량은 10mm로 나타났다. 초기강우 현상을 고려하여 산정한 누적강우량 기준은 4-5mm 사이로 산정되었으며, 연구지역에서의 적정 저류지 용량은 안전율을 고려하여 $12,000m^3$으로 결정되었다. 연구지역에서 연간 유출되는 비점오염물질의 양은 TSS가 435ton/yr, COD가 238ton/yr, TKN이 8,518kg/yr 그리고 TP가 1,816kg/yr로 나타났다. 저류지에서의 비점오염물질 저감량은 TSS가 78.3ton/yr, BOD가 20.4ton/yr, COD가 128.6ton/yr, TKN이 4.6ton/yr 그리고 TP가 980kg/yr의 저감량을 보였다. 저류지의 연간 퇴적물량은 78.3ton/yr로 나타났으며, 연간 퇴적율은 $6.53kg/m^2-hr$로 산정되었다.

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『상한론(傷寒論)』 변병진단체계(辨病診斷體系)에 준거하여 한약 투여 후 호전된 갱년기 증후군 1례 임상 보고 (A Case Report of Menopausal Syndrome treated by Herbal medicine based on Shanghanlun provisions)

  • 박재경
    • 대한상한금궤의학회지
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    • 제8권1호
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    • pp.87-97
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    • 2016
  • Objective : This case report aims to demonstrate the effect of Herbal medicine on menopausal syndrome. Methods : A 54 years woman suffered from menopausal syndrome with hot flush, insomnia and dyspepsia. According to Diagnostic system based on Shanghanlun provisions, the patient was diagnosed with Taeyang-byung and treated by Sosiho-tang decoction at first. But the next time the patient visited, she was treated by Oryeong-san decoction. The result of administrations were evaluated by Kupperman's index(KI), Menopause rating scale(MRS). Results : After administration of Sosiho-tang decoction for 35 days, KI was decreased from 50 to 19, MRS was decreased from 9 to 4. But her chronic dyspepsia wasn't getting better. So the KMD prescribed Oryeong-san decoction. After administration of Oryeong-san decoction for 14 days, KI was decreased from 19 to 0, MRS was decreased from 4 to 1. And her chronic dyspepsia was functionally improved. Conclusions : The patient completely recovered from menopausal syndrome and dyspepsia as treated by Sosiho-tang decoction and Oryeong-san decoction according to Diagnostic system based on Shanghanlun provisions.

주차장 및 교량 강우유출수의 중금속 오염물질 특성과 동적 EMCs (Characteristics of Metal Pollutants and Dynamic EMCs in a Parking Lot and a Bridge during Storms)

  • 김이형;이선하
    • 한국물환경학회지
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    • 제21권4호
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    • pp.385-392
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    • 2005
  • The control of nonpoint source pollution is essentially needed to successfully perform the Total Maximum Daily Load program. Of the various land uses in the nonpoint source, the paved areas such as a parking lot and a bridge are stormwater intensive land uses because of high imperviousness and high pollutant mass emissions. This research was performed to understand the magnitude and nature of the stormwater emissions with the purposes of quantifying stormwater pollutant concentrations and mass emission rates from a parking lot and a bridge. Two monitoring sites in Kongju city were equipped with an automatic rainfall gages and an automatic flow meter for accumulating the data such as rainfall, water quality and runoff flow rates. This paper will summarize the metal concentration changes during the storm duration and metal EMCs to characterize the concentration profiles in a parking lot and a bridge. Also a new concept, dynamic EMC, will be proposed to find the relationship between EMC and first flush effect. It can be used to determine the economical treatment criteria in best management practices.