• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.11a
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• pp.377-381
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• 2006

실험실 규모의 토양컬럼을 사용하여 도금폐수처리장의 유출수를 대상으로 처리한 결과 다음과 같은 결론을 얻었다. 1) 유입수 $NH_4-N$의 대부분은 질산화 토양컬럼에서 질산화 되었으며 HRT가 단축되면 제거율이 낮아졌다. 2) 질산화 토양컬럼에서 생성된 $NO_3-N$은 탈질 토양컬럼에서 탄소원이 없으면 탈질이 이루어지지 않지만 탄소원으로 메탄올을 주입하면 대부분의 $NO_3-N$는 탈질되었다. 3) 탈질 토양컬럼에서 HRT 72시간일때 T-N 제거율은 81.5%이었고 HRT 48시간일 때는 77.8%이었다. 4) 유입수 평균 T-P농도는 13.06 mg/L이고 탈질 토양컬럼에서의 유출수 평균 T-P는 0.83 mg/L로 제거율은 96.83% 이었다. 5) 실험기간 동안의 COD변화는 탄소원으로 메탄올 주입했 때와 HRT 변화시를 제외하고는 25 mg/L이하로 처리되었으며, 질산화 토양컬럼에는 폐굴껍질을 충진한 결과 $NO_3-N$의 생성에도 불구하고 pH 8.5정도를 유지할 수 있었다.

• Journal of Soil and Groundwater Environment
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• v.6 no.1
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• pp.13-21
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• 2001

The characteristics of $Co^{2+}$ removal in the kaolinite column were analyzed by electrokinetic remediation. Ethanoic buffer was injected in the kaolinite column and $CH_3$COOH was continuously added to the cathode reservoir to restrain the pH increase. The pH of the cathode of the kaolinite column was 4.0 at first. Since it was controlled to be under 6.5 after 43.6 hours due to ethanoic buffer, precipitation of ${Co(OH)}_2$ was not formed in the column. Effluent rate increased with time and $Co^{2+}$ removal in the column at initial time was mainly controlled by ion migration. 13.1% of total $Co^{2+}$ in the column was removed after 10 hours, the 46.8% of total $Co^{2+}$ after 20.8 hours, and the 71.7% of total $Co^{2+}$ after 30.1 hours, the 94.6% of total $Co^{2+}$ after 43.6 hours, Meanwhile, the residual concentrations in the column calculated by the developed model were similar to experiment results.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2004.05a
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• pp.329-331
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• 2004

본 연구에서는 토양을 충진한 컬럼을 사용하여 질산화 반응을 촉진시키기 위한 첨가제에 따른 효과를 검토하였다. 토양만을 충진한 컬럼에서는 $NH_{4-}$/N의 약 26%가 질산화 되었으며 제올라이트를 첨가 하였을 때 실험초기에는 $NH_{4-}$/N가 유출되지 않다가 20일 이후부터 $NH_{4-}$/N의 농도가 증가 하기 시작하였으며 이는 제올라이트에 의한 흡착능력의 저하로 사료된다. 폐굴껍질 20% 충진한 토양컬럼에서는 실험 95일까지 99.7%의 질산화율을 보았다. 위의 결과로부터 알 수 있듯이 토양컬럼에 폐굴껍질과 제올라이트를 첨가제로 충진하였을 경우 질산화 반응을 촉진시켜서 질산화율을 높일 수 있음을 확인 할 수 있었다.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.11
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• pp.2007-2016
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• 2000

After kaolin clay was compulsorily contaminated with $Sr^{2+}$ ion. the remediation characteristics by electrokinetic method were analyzed. In the first experiment. NaCl solution was used as an electrolyte to raise the electric field strength. After remediation for 0.8 days. the pH of the cathode side of the soil column was elevated from 4.0 to 11.7. and thereby precipitation $Sr(OH)_2$, started to be formed in the side. Therefore. efficiency of soil remediation was reduced significantly and the 32% of total $Sr^{2+}$ ion in the column was decontaminated in 6.7 days. In the second experiment. ethanoic buffer was injected in the soil column and $CH_3COOH$ was continuously inputted in cathode reservoir to restrain the pH elevation. The pH of the cathode side of the soil column was only ascended from 4.0 to 6.0 in 3.8 days and $Sr(OH)_2$ was not formed. The 21% of total $Sr^{2+}$ in the soil column was decontaminated in 0.6 days. and the 33% of total $Sr^{2+}$ in 0.9 days. and the 84% of total $Sr^{2+}$ in 1.6 days. and the 92% of total $Sr^{2+}$ in 2.5 days. and the 97% of total $Sr^{2+}$ in 3.8 days. Meanwhile. the residual concentrations in the column calculated by the developed model were similar to those by experiment.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2005.05a
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• pp.377-379
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• 2005

실험실 규모의 토양컬럼을 사용하여 고농도의 암모니아성 질소의 질산화 영향을 실험한 결과 다음과 같은 결론을 얻었다. 1) 유입수 NH$_{4}$-N의 농도 50 mg/L와 100 mg/L인 경 우 HRT 48시간에서도 NH$_{4}$-N가 99%정도 제거되었으며 유출수 평균 NO$_{3}$-N의 농도는 각각 46.3 mg/L와 98.3 mgh로 유입수 NH$_{4}$-N는 대부분 NO$_{3}$-N로 전환되었다. 2) 유입수 NH$_{4}$-N의 농도 200 mg/L인 경우 HRT 48시간에서 NH$_{4}$-N의 평균제거율이74.8%에 머물렀으나 토양컬럼 내부에 폭기장치를 설치한 결과 NH$_{4}$-N의 평균제거율은 94.7%로 개선되는 효과를 나타냈으며, 유입수 NH$_{4}$-N의 농도 400 mg/L인 경우에는 HRT 72시 간에서도 질산화가 불안정하였으나 마찬가지로 강제 폭기를 실시 한 결과 질산화가 증가하는 경향을 보였다. 4) 실험종료 후 토양컬럼 내부의 암모니아 및 아질산 산화세균을 조사한 결과 각각 1.4${\times}$10$^{5}$과 2.3${\times}$ 10$^{6}$ MPN/g${\cdot}$soil까지 증가하였다.

• Clean Technology
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• v.23 no.3
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• pp.302-307
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• 2017

This study was conducted to evaluate the feasibility of in situ soil flushing for TPH-contaminated soil remediation with column test. The soil texture of the soil was sand and the initial TPH concentration was $9,369mg\; kg^{-1}$. 0.1% Tween-80 was selected as surfactant solution. And the acrylic and the glass syringe columns were used as reactors. In the acrylic column test, 35% of the initial TPH was removed in 1 PV of flushing and approximately 40% in 5 PV and finally 7 PV showed about 60%. The glass column test showed 3 ~ 12% higher removal efficiency than that of acrylic test until 5 PV of flushing. However, there was no difference in TPH removal efficiency when 7 PV of surfactant was finally flushed. Both of alum only and alum+polymer mixed surfactants showed also the best coagulation efficiency in $150mg\;L^{-1}$ of concentraion. When Tween 80 was newly dissolved in 0.1% to the recovered solution after the coagulation treatment, the removal efficiency was increased from 32.0% to 41.0% in comparison to the new 0.1% Tween 80 solution without reuse by coagulation treatment.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.13-23
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• 2004

The characteristics of cesium and cobalt removal from soil around the TRIGA reactor using the electrokinetic method were analyzed and a device to restrain the pH increase in the soil column was suggested. When a NaCl solution was used as the electrolyte to raise the electric field strength, a precipitate was formed in the cathode in the soil column, resulting in a low removal efficiency. Thus, an acetate buffer solution (compound solution of $CH_3COONa$ and $CH_3COOH$) was injected into the soil column and acetic acid was periodically infected into the cathode reservoir to restrain any pH increase. Many $Cs^{2+}$ and $Co^{2+}$ ions were transferred by electromigration rather than electroosmosis during the initial remediation period, and no precipitate was formed in the soil column. 96% of the total amount of cesium in the soil column was removed after 5.9 days, while 94% of the total amount of cobalt was removed. Furthermore, the residual concentrations predicted by the developed model were similar to those obtained by experiment.

• Journal of Korea Soil Environment Society
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• v.2 no.1
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• pp.35-44
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• 1997

A column study using artificial acid rain was conducted to evaluate the buffering capacities in soil layer and host rock. In an effort to compare the effect of composition of host root two valleys of which compositions of host rock are different were chosen within the study area and the pHs of the water flowing in the valleys were measured from May, 1996 to October, 1996. The pHs of the artificial acid rain prepared by adding appropriate amounts of both sulfuric and nitric acids to distilled water were 3, 4, and 5, and the column effluents were analyzed for major cations and anions. The cation exchange capacities(CECs) of A Horizon and the B Horizon were 9.68 and 6.16 meq/100g, respectively, Compared to the B Horizon, the pH in the column effluent of A Horizon with larger CEC was higher. The sums of $Ca^{2+}$, $Mg^{2+}$, $Na^{+}$in the column effluents gradually decreased, indicating the loss of CEC by acid rain. The field study showed that pHs of the surface water in the valleys increased as the water flows downwards. The magnitude of this buffering capacity was greater for the valley in which smectite in addition to kaolinite and illite was a weathered product of host rocks. This also indicates that host rock as well as soil layer retains the buffering capacity.

• Economic and Environmental Geology
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• v.42 no.5
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• pp.435-444
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• 2009

In situ stabilization of heavy metals through adsorption onto indigenous bacterial biofilm developed on soil particles was investigated. Biofilms were developed in soil columns by supply of various carbon sources such as acetate, lactate and glucose. During development of biofilms, acetate, lactate, and glucose solutions were flew out from the soil columns with volume ratios of 98.5%, 97.3%, and 94.7%, respectively, when compared with soil column supplied with deionized water. Decrease in effluent amounts through the soil columns amended with carbon sources over time indicated the formation of biofilms resulting in decrease of soil porosity. Solutions of Cd, Cr(VI), Cu, Pb, and Zn were injected into the biofilms supported on soil particles in the columns, and the dissolved heavy metals in effluents were determined. Concentrations of dissolved Cd, Cr(VI), Cu, and Zn in the effluents through biofilm columns were lower than those of control column supplied with deionized water. The result was likely due to enhanced adsorption of the metals onto biofilms. Efficiency of metal removal by biofilms depended on the type of carbon sources supplied. The enhanced removal of dissolved heavy metals by bacterial biofilms in this study may be effectively applied to technical development of in situ stabilization of heavy metals in natural soil formation contaminated with heavy metals.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.379-382
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• 2006

본 연구에서는 다양한 토지이용의 불교란 토양칼럼 시료를 대상으로 토양 물리화학 특성 및 자연강우에 대한 토양배수 양상을 분석하였다. 공극률은 토양컬럼에서의 유효공극률과 투수계수 및 자연강우에 대한 배수율과 대체로 정의 상관관계를 보인다. 미국 통일분류법에 따라 토양을 분류하였을 때 소성성이 낮은 실트질 토양과 점토질 토양은 유효공극률이 낮으면서 배수율도 낮고, 소성성이 없는 실트질이 섞인 자갈(유구-논)과 실트질 모래는 유효공극률이 비교적 높으면서 배수율이 다소 높았다. 불교란 토양컬럼을 완전 포화상태에서 자연배수할 때 대부분의 토양은 50시간 전후로 거의 다. 배수되며 $150{\sim}200$시간 경과되면 거의 모든 토양에서 완전배수가 되었다. 일부 500여시간이 경과되어도 지속적으로 배수되는 토양이 있는데 이는 토양수분보유특성에 기인하는 것으로 사료된다. 배수량으로 가정한 함양량 실측실험에서는 오송(전의)임야 > 무주-밭, 무주-논 > 유구-임야 > 김해-밭 > 유구-논, 유구-밭 순으로 높았으며 이들 시료들의 함양률은 50% 이상이었다. 토성에 따른 자연강우 배수상태를 보면, 소성성이 낮은 실트질 토양의 배수율이 낮고, 실트질 모래는 다양한 배수상태를 보이나 대체로 배수율이 높다. 그리고 1차, 2차 실험에서 선행 강우 5mm 미만은 토양배수에 영향을 미치지 않았다.