• 한국토양비료학회지
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• 제24권1호
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• pp.35-40
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• 1991

유기물(볏짚)의 병용과 부숙이 탄산석회에 의한 갯흙의 제염에주는 영향을 밝히기 위하여 컬럼시험을 한 결과는 아래와 같다. 1. 볏짚과 탄산석회를 미리 시용하여 부숙시켰을 경우는 투수속도가 빨라졌으나 석고처리에는 미치지 못했으며, 제염(Na) 효과는 $CaCO_3$단용 또는 $CaCO_3$+볏짚분(미부숙)을 따르지 못하였다. 부식된 볏짚에 흡착되어 제염이 늦어진 것으로 판단되었다. 2. Na와 Mg를 치환 침출하기에 충분하지 못한(1/3) $CaCO_4$를 시용했을 경우와 $CaCO_3$만을 시용했을 경우는 표층에 Mg를 집적시키고 그 직하층에서 Mg 를 용탈하여 아랫층에 집적시켰으니, 볏짚분이 병용된 처리에서는 이런 용탈현상없이 물리세탈만이 일어났다. 3. $Na^+$의 제염은 세탈용액의 염농도와 비례하는 것으로 보여서, 상충토가 세탈되여 하충토양용액의 염농도가 높아졌을 경우는 염농도가 높아진 층에서 $Na^+$의 치환제거가 많다. 이 말은 염류의 공급원이 세탈되면 표층토의 Na제염이 부진하다는 것을 의미한다.

• 한국환경농학회지
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• 제12권1호
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• pp.9-17
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• 1993

$^{14}C-Carbofuran$, $^{14}C-Bentazon$, 그리고 $^{14}C-3,3',4,4'-tetrachloroazobenzene$의 신생잔류물 및 3개월과 6개월 숙성잔류물의 용탈행적을 Soil column중에서 연구하였다. 농약의 토양중 분해, 이동성, 그리고 지하수의 오염가능성 등을 검토하기 위하여 본 실험에서는 온도 $15{\pm}2^{\circ}C$, Soil column에는 정수두법에 의한 관수, 그리고 1,332ml의 모조강우량을 90일간 용출시켜 실시하였다. $^{14}C-Carbofuran$과 $^{14}C-Bentazon$의 신생잔류물은 매우 큰 이동성을 보였으나, 숙성잔류물은 이동성이 현저히 감소하였다. 반면, $^{14}C-TCAB$의 신생 및 숙성잔류물은 이동성이 전혀 없었다. 3-Keto carbofuran phenol(2,3-dihydro-2,2-dimethyl-3-oxo-7-benzofuranol)은 $^{14}C-carbofuran$의 신생잔류물로 처리한 Soil column의 Leachate중에서 주분해산물로 검출되었지만, $^{14}C-bentazon$과 $^{14}C-TCAB$를 처리한 Soil column의 Leachate중에서는 분해산물을 검출할 수 없었다.

• 한국지반공학회논문집
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• 제19권4호
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• pp.145-153
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• 2003

공진주 실험은 탄성파 이론을 이용하여 흙의 동적 물성, 즉 전단변형률의 크기에 따른 전단탄성계수와 재료감쇠비를 측정하는 실험이다. 공진주 실험에 의한 시료의 동적물성의 측정은 공진주 실험 시스템의 동적 거동에 대한 이해를 전제로 한다. 공진주 실험의 시료 및 실험장치의 구성은 고정단-자유단 경계조건을 가지고 있는 연속보로 단순화할 수 있어서, Richart, Hall and Woods는 공진주 실험 시스템에 대한 파동방정식을 유도하였으나, 시료를 단순히 탄성으로 가정하였고 시료의 점성을 고려하지는 않았다. 그리고, Hardin은 파동방정식의 유도에서 시료의 점탄성을 고려하였으나, 시료의 전단탄성계수를 결정하기 위하여 시료의 점탄성을 가정하여야 하는 문제점을 가지고 있었다. 본 연구에서는 기존의 연구자들이 시도했던 공진주 실험 시스템에 대한 파동방정식을 새로운 측면에서 유도하였으며, 새로이 유도된 파동방정식의 해법을 제안하였다. 한편, 일반적으로 시스템에 대한 동적 거동을 이해하는 방법으로, 시스템의 운동방정식을 이용하는 방법이 있으나, 공진주 실험 시스템에 대한 동적 거동의 해석방법으로 이와 같은 운동방정식을 이용하는 해석방법을 연구한 경우는 거의 없었다. 운동방정식에 의한 해법은 시스템의 동적 증폭계수와 동적 응답에 대한 위상각을 구할수 있기 때문에 파동방정식에 대한 해법보다 더 많은 정보를 활용할 수 있는 장점이 있다. 따라서, 본 연구에서는 공진주 실험 시스템에 대한 보다 기본적이고 많은 정보를 도출하기 위하여, 공진주 실험 시스템에 대한 운동방정식을 유도하였으며, 이를 이용하여 공진주 실험자료를 해석하는 새로운 해석기법의 제안을 위한 근간을 마련하였다. 그리고, 공진주 실험 시스템에 대한 유한요소 해석을 수행하여, 본 연구에서 제안한 공진주 실험시스템의 이론적 모델링의 타당성과 합리성을 검증하였다.

• 한국토양비료학회지
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• 제47권6호
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• pp.406-411
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• 2014

Serious problems in reclaimed land agriculture are high soil salinity and poor vertical drainage, so desalinization in these soils is very difficult. Also, although desalinization is accomplished in reclaimed top soils, before long, soils are resalinized according to capillary rise of salts from the subsurface soils. To resolve these problems, multi-layered soil columns with subsurface layer of macroporous medium utilizing coal bottom ash (CBA) were constructed and the effects of blocked resalinization of these soils were investigated. In this experiment soil samples were collected from Munpo series (coarse-loamy, nonacid, mixed, mesic, typic Fluvaquents). The soil texture was silt loam and the EC was $33.9dS\;m^{-1}$. As for groundwater seawater was used and groundwater level of 1 cm from the bottom was maintained. The overall rate of capillary rise was $2.38cm\;hr^{-1}$ in soil 60 cm column, $0.25cm\;hr^{-1}$ in topsoil (30 cm) + CBA (5 cm) + subsurface soil (10 cm) column and $0.08cm\;hr^{-1}$ in topsoil (30 cm) + CBA (10 cm) + subsurface soil (10 cm) column. In multi-layered soil columns with CBA 20, 30 cm layer, wetting front due to capillary rise could not be seen in top soil layer. After 70 days capillary rise experiment water soluble Na+ accumulated in top soil of soil columns with CBA 20, 30 cm was diminished by 92.8, 96.5% respectively in comparison with Na+ accumulated in top soil of soil 60 cm column because CBA layer cut off capillary rise of salts from the subsurface soil. From these results we could conclude that the macroporous layer utilizing CBA placed at subsurface layer cut off capillary rise of solutes from subsurface soil, resulting in lowered level of salinity in top soil and this method can be more effective in newly reclaimed saline soil.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1998년도 공동 심포지엄 및 추계학술발표회
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• pp.201-205
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• 1998

Leakage of hydrocarbon compound from underground storage tank has been a significant issue to the hazard of environmental contaminants. It is therefore necessary to develop the measurement technique of hydrocarbon compound concentration. In this study, the possibility of TDR application to measure concentration of hydrocarbon compound, especially diesel, in a sandy soil was investigated. Experiments were conducted in two different conditions. The first one was to measure the resistances of the soil columns packed according to the various ratios of tab water and diesel content in the total voids. The other was to measure the resistance of the soil under the flow condition where diesel oil was allowed to infiltrate into the KCl-saturated soil column. The experimental results showed that there exists a significant relationship between oil% and TDR-measured resistance. This suggests that TDR can be an effective device to measure the concentration of hydrocarbon compound in a soil.

• 대한환경공학회지
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• 제22권11호
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• pp.2007-2016
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• 2000

Kaolin clay 토양을 $Sr^{2+}$로 오염시킨 후 동전기적 방법으로 수일간 토양제염실험을 수행했다. 첫 번째 실험으로, 컬럼 내의 전기장을 높이기 위해 전해물질로 NaCl용액을 사용하였다. 토양제염결과 0.8일 경과 후 토양컬럼의 음극쪽에서의 pH는 초기의 4.0으로부터 약 11.7로 상승하면서 음극쪽 토양컬럼에서는 $Sr(OH)_2$가 형성되기 시작했다. 6.7일 동안의 실험결과 토양컬럼 14cm지점에 앞에서 이동된 $Sr^{2+}$들이 침전을 형성하며 계속 쌓이고 거의 이동되지 않기 때문에 제염효율은 32%에 불과했다. 두번째 실험으로, pH의 상승을 억제하기 위해 토양컬럼내에 초산완충액을 넣고, 음극저수조에는 0.1 M $CH_3COOH$을 연속적으로 주입했다. 컬럼의 14cm 뒤쪽 부분의 pH는 초기에는 4.0이었으나 실험이 끝나는 3.8일까지는 약 6.0으로 상승하여 컬럼 내에 $Sr(OH)_2$는 형성되지 않았다. 토양제염실험 결과 0.6일 후에는 토양컬럼 내의 초기 총농도의 21%가 제염되었고, 0.9일 후에는 33%가 제염되었다. 또한 1.6일 경과 후에는 84%가 제염되었고, 2.5일 후에는 92%, 그리고 3.8일 후에는 97%가 제염되었다. 또한 개발된 모델에 의해 계산된 토양컬럼 내의 잔류농도와 토양제염실험 후에 측정한 잔류농도는 상당히 일치했다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.736-742
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• 2010

This study was conducted to characterize on the relationships of rainfall intensity and infiltration rate of rainfall dependent on unit weight change in the gneissic weathered soil by a column test equipment. In this study, volumetric water content and pore water pressure were measured using TDR sensors and tensiometers at regular time intervals. Rainfall conditions including continuous rainfall and repeated rainfall were selected in order to know the effect of antecedent rainfall. In the condition of rainfall intensity 20mm/h and the unit weights of soil as $1.35g/cm^3$, $1.55g/cm^3$ and $1.61g/cm^3$, average rainfall infiltration rate was $2.814{\times}10^{-3}cm/sec$, $1.969{\times}10^{-3}cm/sec$ and $1.252{\times}10^{-3}cm/sec$ respectively. The higher rainfall intensity and lower unit weight of soil, the faster average infiltration rate. Overflow in the column was happened except rainfall condition of rainfall intensity 20mm and soil unit weight $1.35g/cm^3$. Increasing the soil unit weight, overflowed water was increased and occurrence time was faster.

• 한국물환경학회지
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• 제22권5호
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• pp.824-830
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• 2006

Several tests were conducted to optimize the design parameters of ln-situ soil flushing processes for diesel contaminated soil. According to the batch extraction test for three anionic surfactants evaluation, Calgonit limiting bubble occurrence was selected for its higher oil cleaning efficiency. After optimum surfactant selection, there were many sets of column flushing test. Over 70% of BTEX was removed in this surfactant dose with 400% of soil volume. In the case of no surfactant addition flushing in column, so called "blank flushing test", BTEX removal rate was 64%. But when we reused the effluent for the cleaning solution, the removal rate was decreased to 46.9%. This result showed reabsorption of oil occurred on the soil. With the addition of Calgonit solution to the diesel contaminated column, BTEX was removed up to 98.9% during the first flushing and 99.4% for the second recirculation flushing. In microcosm tests, diesel contaminated soils were cleaned by both surfactant flushing and biological activities. In anoxic condition, nitrate was used as an electron acceptor while the surfactant and the oil were used an electron donor. BTEX removal efficiency could be achieved up to 80% by biological degradation.

• Membrane and Water Treatment
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• 제14권2호
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• pp.95-106
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• 2023

In the developing country like India, groundwater is the main sources for household, irrigation and industrial use. Its contamination poses hydro-geological and environmental concern. The hazardous waste sites such as landfills can lead to contamination of ground water. The contaminants existing at such sites can eventually find ingress down through the soil and into the groundwater in case of leakage. It is necessary to understand the process of migration of pollutants through sub-surface porous medium for avoiding health risks. On this backdrop, the present paper investigates the behavior of pollutants' migration through porous media. The laboratory experiments were carried out on a soil-column model that represents porous media. Two different types of soils (standard sand and red soil) were considered as the media. Further, two different solutes, i.e., non-reactive and reactive, were used. The experimental results are simulated through numerical modeling. The percentage variation in the experimental and numerical results is found to be in the range of 0.75- 11.23 % and 0.84 - 1.26% in case of standard sand and red soil, respectively. While a close agreement is observed in most of the breakthrough curves obtained experimentally and numerically, good agreement is seen in either result in one case.

• 상하수도학회지
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• 제23권5호
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• pp.599-608
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• 2009

This manuscript covers the results of field investigation and lab-scale experiments to design a double-layered biofilter system to control urban storm runoff. The biofilter system consisted of a coarse soil layer (CSL) for filtration and fine soil layer (FSL) for adsorption and biological degradation. The variations of flow rate and water quality of runoff from a local expressway were monitored for seven storm events. Laboratory column experiments were performed using seven kinds of soil and mulch to maximize pollutants removal. The site mean concentration (SMC) of storm runoff from the drainage area (runoff coefficient: 0.92) was measured to be 203 mg/L for SS, 307 mg/L for $TCOD_{Cr}$, 12.3 mg/L for TN, 7.3 mg/L for ${NH_4}^+-N$, and 0.79 mg/L for TP, respectively. This study employed a new design concept, to cover the maximum rainfall intensity with one month recurrence interval. Effective storms for last ten years (1998-2007) in seoul suggested the design rainfull intensity to be 8.8 mm/hr Single layer soil column showed the maximum removal rate of pollutants load when the uniformity coefficient of CSL was 1.58 and the silt/clay contents of FSL was virtually 7%. The removal efficiency during operation of double layer soil column was 98% for SS and turbidity, 75% for TCODCr, 56% for ${NH_4}^+-N$, 87% for TP, and 73-91% for heavy metals. The hydraulic conductivity of the soil column, 0.023 cm/sec, suggested that the surface area of the biofilter system should be about 1% of the drainage area to treat the rainfall intensity of one month recurrence interval.