• Title/Summary/Keyword: precipitation environment

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다종 중금속으로 오염된 사질토에 대한 EK Flushing 기술 적용

  • 김병일;한상재;이군택;김수삼
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2003.09a
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    • pp.310-313
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    • 2003
  • The precipitation of heavy metals within the region of pH jump is inevitable in the conventional electrokinetic remediation technology. This study prevents the interest species from precipitating through the injection of flushing solutions in which HCl, acetic acid, citric acid, EDTA and SDS dissolved. The cumulative flow resulted from electroosmosis appear in order of Citric acid

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A study on electric current variation characteristics during Electrokinetic remediation of kaolinite contaminated by Pb (납으로 오염된 카올린의 Electrokinetic 정화기법 적용시 전류변화 특성에 관한 연구)

  • 김정환;한상재;김수삼
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2000.11a
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    • pp.302-306
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    • 2000
  • In case of applying electrokinetic remediation, magnitude of electric current is one of major factors for estimation of contaminant transport. In practice, electric current provide determination of electric conductivity based on specimen resistance. Electric current variation is produced during Electrokinetic remediation test. Electric current is decreased by expotential function according to time in condition of constant voltage. This can be interpreted as precipitation effect by OH$^{-10}$ generation in a cathode.

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Prediction of Temporal Variation of Son Concentrations in Rainwater (산성비 모델을 이용한 시간별 강우성분 예측)

  • 김순태;홍민선;문수호;최종인
    • Journal of Korean Society for Atmospheric Environment
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    • v.19 no.2
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    • pp.191-204
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    • 2003
  • A one dimensional time dependent acid rain model considering size distribution of aerosols and hydrometeors is developed to predict observed chemical and physical properties of precipitation. Temporal variations of anions and cations observed are predicted fairly well with acid rain model simulations. It is found that aerosol depletion rates are highly dependent on aerosol sizes under the assumption of Marshall - Palmer raindrop size distribution. Also, the aerosol depletion during the initial rain event largely influences on ion concentrations in rainwaters.

Prediction of Soil Erosion from Agricultural Uplands under Precipitation Change Scenarios (우리나라 강우량 변화 시나리오에 따른 밭토양의 토양 유실량 변화 예측)

  • Kim, Min-Kyeong;Hur, Seong-Oh;Kwon, Soon-Ik;Jung, Goo-Bok;Sonn, Yeon-Kyu;Ha, Sang-Keun;Lee, Deog-Bae
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.6
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    • pp.789-792
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    • 2010
  • Major impacts of climate change expert that soil erosion rate may increase during the $21^{st}$ century. This study was conducted to assess the potential impacts of climate change on soil erosion by water in Korea. The soil loss was estimated for regions with the potential risk of soil erosion on a national scale. For computation, Universal Soil Loss Equation (USLE) with rainfall and runoff erosivity factors (R), cover management factors (C), support practice factors (P) and revised USLE with soil erodibility factors (K) and topographic factors (LS) were used. RUSLE, the revised version of USLE, was modified for Korean conditions and re-evaluate to estimate the national-scale of soil loss based on the digital soil maps for Korea. The change of precipitation for 2010 to 2090s were predicted under A1B scenarios made by National Institute of Meteorological Research in Korea. Future soil loss was predicted based on a change of R factor. As results, the predicted precipitations were increased by 6.7% for 2010 to 2030s, 9.5% for 2040 to 2060s and 190% for 2070 to 2090s, respectively. The total soil loss from uplands in 2005 was estimated approximately $28{\times}10^6$ ton. Total soil losses were estimated as $31{\times}10^6$ ton in 2010 to 2030s, $31{\times}10^6$ ton in 2040 to 2060s and $33{\times}10^6$ ton in 2070 to 2090s, respectively. As precipitation increased by 17% in the end of $21^{st}$ century, the total soil loss was increased by 12.9%. Overall, these results emphasize the significance of precipitation. However, it should be noted that when precipitation becomes insignificant, the results may turn out to be complex due to the large interaction among plant biomass, runoff and erosion. This may cause increase or decrease the overall erosion.

Characteristics of Surface and Synoptic Meteorology During High-Ozone Episodes in the Greater Seoul Area (서울.수도권 지역 고농도 오존 사례의 지상 및 종관 기상 특성)

  • 오현선;김영성
    • Journal of Korean Society for Atmospheric Environment
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    • v.15 no.4
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    • pp.441-455
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    • 1999
  • Meteorological characteristics of three high-ozone episodes in the Greater Seoul Area, selected on the basis of morning-average wind direction and speed for the 1990~1997 period, were investigated. Three high-ozone episodes thus selected were seven days of July 3~9, 1992, nine days of July 21~29, 1994, and three days of August 22~24, 1994. Along with surface meteorological data from the Seoul Weather Station, surface and 850-hPa wind fields over the Northest Asia around the Korean Peninsula were used for the analysis. In the July 1992 episode, westerly winds were most frequent as a result of the influence of a high-pressure system in the west behind the trough. In contrast, in the July 1994 episode, easterly winds were most frequent due to the effect of a typhoon moving north from the south of Japan. Despite different prevailing wind directions in the two episodes, the peak ozone concentration of each episode always occurred when a sea-land breeze developed in association with weak synoptic forcing. The August 1994 episode, selected as being representative of calm conditions, was another typical example in which peak ozone concentration rose to 322 ppb under the well-developed sea-land breeze. All three high-ozone episodes were terminated by precipitation, and subsequent rises in ozone concentrations were also suppressed by a series of precipitation afterwards. In particular, two heavy rainfalls were the main reason why the August 1994 episode, with the highest and second-highest ozone concentrations during the 1990~1997 period, lasted for only a few days.

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