• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.191-194
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• 2002

토양증기추출(Soil Vapor Extraction)법을 이용하여 대표적 휘발성 NAPL (Non-aqueous phase liquid)인 TCE (trichloroethylene)와 toluene을 토양으로부터 제거하는 칼럼 실험을 실시하였다. 토양특성 및 증기추출 조건들이 정화효율에 미치는 영향을 규명하는데, 균질한 Ottawa sand와 실제 오염지역의 토양들을 직경 2.5cm, 길이 30cm인 유리 칼럼이 충진시켰으며, 빨갛게 염색된 TCE 또는 toluene 4 g이 주입되었다 공기 유량계를 설치하여 0.03L/min의 일정한 속도로 공기가 주입되도록 하고, 퍼지장치를 설치하여 주입 공기의 습윤도를 99% 이상으로 유지하였다. 가스크로마토그래피로 유출 가스 농도를 분석하였다. Ottawa sand로 충진된 칼럼실험에서는 매질의 입자크기, 함수율, 토양 내 오염물 체류시간 등을 변화시켜 실험을 반복하였다. TCE로 오염된 세립질 Ottawa sand 칼럼실험에서 유출 공기의 최대 농도는 조립질 Ottawa sand 칼럼의 유출 농도보다 약 20% 정도 감소하였고, 오염지역의 실제토양 칼럼실험에서는 최대유출농도가 조립질 Ottawa sand 칼럼의 농도보다 약 50% 감소하였으나, 20 liter공기 주입 후부터는 모두 비슷한 농도감소 현상을 나타내었으며, 초기 주입량의 90 % 이상이 제거되었다. 함수율증가에 따른 유출공기의 농도 감소는 거의 나타나지 않았으며, TCE 주입 후 7일 동안 방치하였다가 SVE를 실시한 칼럼 실험에서도 잔류하는 TCE의 양이 약간 증가하였지만 20 liter 공기 추출 후에는 초기 주입량의 90% 가, 40 liter공기 추출 후에는 98% 이상이 제거되었다. Toluene으로 오염된 칼럼 실험에서도 TCE와 비슷한 제거 경향을 나타냈으며 200 liter 공기 추출 후에는 오염물 초기 주입량의 98% 이상이 제거되었다. 본 실험 결과로부터 증기추출법을 이용한 TCE, toluene 정화 효율성이 규명되었으며, 휘발성 NAPL로 오염된 실제 토양을 복원하기 위한 SVE법의 적용가능성을 확인할 수 있었다.

• Proceedings of the KAIS Fall Conference
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• 2002.05a
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• pp.137-139
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• 2002

이온교환은 액체상 이온과 고체상 이온간의 화학반응이며 연수 및 탈염공정, 특정물질의 제거 및 회수, 토양을 통한 이온성 물질의 이동에서 널리 이용되고 있다. 이온교환수지는 이온교환시 원자가가 높을수록, 수화반경이 작을수록, 이온농도가 낮을수록 증가한다. 본 연구는 이온교환수지에 대한 평형실험을 선택도가 칼럼실험에 적용되는지 조사하였다. 이 실험치 결과에서 음이온 교환수지의 선택도 순서는 OH/sup -/ < F/sup -/ < HCO₃/sup -/ < Cl/sup -/ < Br/sup -/ ≤ No₃/sup -/ < So₄/sup 2-/ 이였으며, 음이온 칼럼 교환도 동일하였다. 또한 바탕 양이온의 가수가 높을수록 이온교환이 빠르게 진행됨을 알 수 있다.

• Journal of Energy Engineering
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• v.9 no.1
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• pp.28-36
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• 2000

태양열 시스템에 사용되는 간접접촉을 열교환기는 열전달률감소, 부식, 스케일링 등의 문제에 기인하는 단점을 갖고 있다. 이러한 문제들을 해결하기 위하여 직접접촉 열교환기의 사용이 제안된다. 본 연구에서는 직접접촉 열교환기로서 분사칼럼이 도입되었다. 열전달률을 증가기키기위하여 작동유체는 연속유체와의 접촉면적을 증가시키기위하여 칼럼내에서 작고 균일한 방울들로 분산된다. 또한 작고 균일한 방울들로 만들기 위하여 열교환기 칼럼내에서 메쉬가 설치되었다. 디에틸 프탈레이트(Diethyl Pthalate , 밀도 : 1,052g/㎤)가 작동유체로 사용되었고, 메쉬가 있는 경우와 없는 경우로 비교 실험되었다. 실험중 칼럼의 길이방향으로 온도측정을 하였고, 두 유체간의 직접접촉 열교환 메카니즘을 알기 위하여 방울의 사진을 통하여 분석하였다. 방울이 제트형태로 형성될 때 방울은 작고 균일하였다. 한편 방울형태로 형성될 때는 크고 불균일하게 관찰되었으나 , 메쉬를 통해 칼럼내에서 효과적으로 작고 균일한 방울들로 되었다.

• Journal of Soil and Groundwater Environment
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• v.13 no.1
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• pp.52-59
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• 2008

Adsorption is a major process causing the accumulation of arsenic onto soil. Therefore, further understanding of the adsorption/desorption characteristics of arsenic species on soil is essential for predicting their fate and preparing appropriate remediation strategy to remove arsenic from soil. In this study, the column adsorption/desorption experiment has been performed with As(III) and As(V) on soil. Experiment with As(III) was conducted under reducing condition, whereas that with As(V) was under oxidizing condition. Most of As(III) was remained on the oxidation state during the experiment. The results showed that the adsorption/desorption rate of As(III) was higher than that of As(V). Adsorption and desorption of arsenic species were not completely reversible in the column experiment. It was also found that As(V) in the column experiment was adsorbed more rapidly on soil than in the batch experiment.

• Journal of the Korean Geotechnical Society
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• v.28 no.4
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• pp.115-124
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• 2012

The responses of stone column-improved ground under seismic loading are investigated using a series of 1g shaking table tests. These tests show similar results to those of one dimensional numerical models for stone column-improved ground based on Baez's assumption on the soil and stone-column interaction. The experimental and numerical results show that the stone column can prevent large shear deformations incurred due to cyclic softening in clayey deposits, but they also show that the surface acceleration in the improved clayey deposits may amplify more than that in unimproved clayey deposits when subjected to short periodic seismic motions.

• Economic and Environmental Geology
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• v.35 no.3
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• pp.221-227
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• 2002

Column experiments were performed to evaluate the removal efficiency of soil vapor extraction (SVE) iota TCE (trichloroethylene) and toluene in soil. Homogeneous Ottawa sands and real soils collected from contaminated area were used to investigate the effect of soil properties and SVE operation conditions on the removal efficiency. In column teats with two different sizes of Ottawa sand, the maximum effluent TCE concentration in a coarse sand column was 442 mg/L and 337 mg/L in a fine sand column. However, after 20 liter gas flushing, the effluent concentrations were very similar and more than 90% of initial TCE mass were removed from the column. For two real contaminated soil columns, the maximum effluent concentration decreased 50% compared with that in the homogeneous Ottawa coarse sand column, but 99% of initial TCE mass were extracted from the column within 40 liter air flushing, suggesting that SVE is very available to remove volatile NAPLs in the contaminated soil. To investigate the effect of contaminant existing time on the removal efficiency, an Ottawa sand column was left stable for one week after TCE was injected and the gas extraction was applied into the column. Its effluent concentration trend was very similar to those for other Ottawa sand columns except that the residual TCE after the air flushing showed relatively high. Column tests with different water contents were performed and results showed high removal efficiency even in a high water content sand column. Toluene as one of BTEX compounds was used in an Ottawa sand column and a real soil column. Removal trends were similar to those in TCE contaminated columns and more than 98% of initial toluene mass were removed with SVE in both column.

• Proceedings of the KAIS Fall Conference
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• 2002.05a
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• pp.134-136
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• 2002

이온교환 수지는 이온성 물질을 제거하는 가장 신31성 있는 단위공정일 뿐만 아니라 재사용의 측면에서 매우 경제적이다. 특히 토양화학 분야에서 지난 한세기 동한 수많은 연구가 진행되어 왔으며, 이온교환은 연수 및 탈염공정, 특정물질의 제거 및 회수, 토양을 통한 이온성 물질의 이동에서 널리 이용되고 있다. 이온의 선택도는 이온의 수화반경과 용액의 농도, 이온의 원자가에 따라 좌우된다. 본 연구는 양이온 평형실험과 칼럼실험을 통해 이온사이의 선택도 순서와 바탕음이온에 따른 특성을 조사하였다. 이 실험의 결과에서 양이온의 선택성의 농도가 낮을수록, 이온의 원자가가 높을수록 증가하였다. 평형실험의 양이온 선택도 순서는 H/sup +/< K/sup +/< Cu/sup 2+/ < Co/sup 2+/ < Ca/sup 2+/ < Ce/sup 3+/ 이며, 양이온 칼럼 순서도 동일함을 알 수 있다.

• Journal of the Korean GEO-environmental Society
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• v.15 no.8
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• pp.39-44
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• 2014

Effects of operating parameters on the breakthrough properties of Pb(II) by $Mn_3O_4$ coated activated carbon prepared by supercritical technique were investigated through fixed-bed column experiments. The mass transfer zone and equilibrium adsorption capacity were enhanced about 2.8 times for Pb(II) by $Mn_3O_4$ coating onto activated carbon. Increase of bed height enhanced the residence time of Pb(II) in adsorption zone, giving the higher breakthrough time, mass transfer zone and equilibrium adsorption capacity. Increase of flow rate reduced the residence time and diffusion of Pb(II) in adsorption zone, therefore decreased the equilibrium adsorption capacity. The higher inlet concentration of Pb(II) decreased the breakthrough time and mass transfer zone through the promotion of Pb(II) transfer onto adsorbent.

• Journal of Life Science
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• v.19 no.9
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• pp.1284-1288
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• 2009

To produce high quality fish oil products, additional deodorization experiments on purified fish oil from squid using columns filled with citric acid or gluconic acid were performed. A deodorization effect on the fish oil was observed on both the citric acid and gluconic acid columns. These effects were more efficient on the columns packed with 3 g of organic acid than those with 1 g or 2 g of organic acid. In addition, a better effect was observed in the column packed with gluconic acid than that with citric acid. Peroxide value (POV) and acid value (AV) of the sample treated with citric acid was the as same as the non-treated sample. However, POV and AV of the sample treated with gluconic acid were about 10% higher than the non-treated sample. Contents of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) of the samples treated with citric acid or gluconic acid columns were about 0.5% higher than the non-treated sample. In conclusion, deodorization of squid fish oil by organic acid could be an efficient method to produce high quality fish oil products.

• Journal of Korea Water Resources Association
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• v.53 no.10
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• pp.861-870
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• 2020

As the flow velocity and Reynolds number increase in rockfill porous media, the flow deviates from Darcy conditions. In this study, the permeability tests of rock column specimen and laboratory gabion weir model were carried out to investigate a head loss behaviour of flow through rockfill deposition in small river artificial recharge. Through column test, the nonlinear relationships between flow velocity and hydraulic gradient and coefficients were determined and the correlation formula of hydraulic mean radius and coefficients was proposed. The flow velocities and discharges in voids estimated by proposed equations were well matched with the measured values of laboratory gabion weir model.