• Title/Summary/Keyword: First flush effect

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

  • Park, Jin-Kyu;Lee, Nam-Hoon;Kim, Hae-Ryong;Lee, Woong;Lee, Chae-Young
    • Journal of Korean Society of Water and Wastewater
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    • v.25 no.6
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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.

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

  • Kim, Lee-Hyung;Lee, Seonha
    • Journal of Korean Society on Water Environment
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    • v.21 no.3
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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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    • v.14 no.9
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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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    • v.14 no.3
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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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    • v.3 no.2
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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.

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

  • Kim, Seog-Ku;Kim, Young-Im;Kang, Sung-Won;Yun, Sang-Leen;Kim, So-Jung
    • Journal of Korean Society of Environmental Engineers
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    • v.28 no.1
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    • pp.104-110
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    • 2006
  • Growth in population and urbanization has progressively increased the loadings of pollutants from non-point sources as well as point sources. Accordingly, release of contaminants from non-point sources, released with surface runoff of rainwater, is influenced by atmospheric phenomena, geology, and topography. This makes the control of non-point source difficult. Therefore, this study intends to reveal the characteristics of runoff and particle size distribution to observe the fundamental characteristics of runoff. Experiments were carried out at inner road of research center. Average concentration of runoff ranged from 26.8 to 126.4 mg/L for SS and $COD_{Cr}\;15.3{\sim}117.7mg/L,\;TN\;0.07{\sim}5.16mg/L,\;TP\;0.06{\sim}0.49mg/L$ and heavy metals $0.00{\sim}0.29mg/L$. First flush, indicated wash off of pollutant at first rain, was observed for all types of pollutants. Most pollutants revealed a very close correlation with SS ($R^2=0.93{\sim}0.99$). After analyzing characteristics of particle, particle was finer than that from previously examined data.

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

  • Ryu, Kwang-Hyun;Lee, Geon-Jik;Seong, Jin-Uk;Kim, Dong-Sup;Park, Jae-Chul
    • Korean Journal of Ecology and Environment
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    • v.44 no.2
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    • pp.178-186
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    • 2011
  • This study was conducted to investigate runoff characteristics of non-point pollutant sources in an agricultural area watershed in Boeun area, Chungbuk Province. The monitoring site represented 1.56 $km^2$, about 44.4% of which was covered with paddy fields. The monitoring was conducted for six events in a period of 5 month. Event Mean Concentration (EMC) and Site Mean Concentration (SMC) of suspended solids (SS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen (T-N) and total phosphorus (T-P) were calculated using the results of the water quality parameters. A comparison between arithmetic mean concentration and EMC revealed that nearly all EMCs were higher than the corresponding arithmetic mean concentrations. First-flushing effects were exhibited for SS, BOD, and T-P, with relatively high concentrations in early-stage storm events.

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

  • Kim, Lee-Hyung;Lee, Byung-sik;Kwon, Soo-Youl
    • Journal of Wetlands Research
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    • v.7 no.3
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    • pp.75-85
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    • 2005
  • The Construction of industrial complex areas means the increase of imperviousness rate and the increase of nonpoint pollutant emissions during a rainfall. Generally the retention basin can become the alternative for removing and controling these nonpoint pollutants. Recently Ministry of Environment are trying to change the purpose of retention basins from flooding control to nonpoint pollutant control. In order to propel the stormwater management program, administration plan of stormwater management is enacted in Spring, 2005. Hereafter, in a newly developing area, the best management practices should be established to control the nonpoint pollutant. Landuses of the research area are classified to the categories of the 1st manufacturing industry, metal industry, fiber and chemical product manufacturing industry, etc. Therefore, this research was performed to understand washed-off characteristics of stormwater and to suggest the controling method of nonpoint pollutants. The optimum capacity of the retention basin can be determined by analyzing the relationships among data of rainfall, runoff, washed-off pollutants from the areas. The rainfall analysis using the data of normal year, recent 2, 5 and 10 years shows that the 80% rainfall frequency was occurred on 10mm accumulated rainfall, but which is not considered the first flush effect. However, by considering the first flush effect, the appropriate treatment capacity of rainfall can be decreased to 4-5mm accumulated rainfall. Using the criteria, the optimum capacity of retention basin is determined to $12,000m^3$ in the research area. The washed-off nonpoint pollutant loading from the areas have beeb calculated to 435ton/yr for TSS, 238ton/yr for COD, 8,518kg/yr for TKN and 1,816kg/yr for TP. The mass of 78.3ton/yr for TSS, 20.4ton/yr for BOD, 128.6ton/yr for COD, 4.6ton/yr for TKN and 980kg/yr for TP can be reduced by constructing the retention basin. The sediment accumulation rate is also calculated by $6.53kg/m^2-hr$.

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

  • Park, Jae Kyung
    • 대한상한금궤의학회지
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    • v.8 no.1
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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.

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

  • Kim, Lee-Hyung;Lee, Seonha
    • Journal of Korean Society on Water Environment
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    • v.21 no.4
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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.