• 한국농공학회:학술대회논문집
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• 한국농공학회 2005년도 학술발표논문집
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• pp.355-360
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• 2005

The properties of contaminants, contaminated soil, and the elapsed time are important factors to in-situ soil remediation. Gabr et. al. (1996) derived the solution equation of contaminant concentration ratio as initial one $(C/C_0)$ with time and spatial changes in contaminated area with vertical drains. The contaminant concentration ratio $(C/C_0)$ is analyzed with time and spatial changes as varying the effective diameter, porosity, shape factor, density of contaminated soil and temperature in ground and unit weight, viscosity of contaminants by using FLUSH1 model. Results from numerical analysis indicate that the most important factor to the in-situ soil remediation using vertical drains is the effective diameter of contaminated soil. It also shows that the viscosity of contaminants, porosity of soil, shape of soil, temperature in ground, unit weight of contaminants are, in order, affected to the soil remediation but density of soil is insignificant to the soil remediation.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 봄 학술발표회 논문집
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• pp.739-742
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• 2002

Immobilization of contaminants in contaminated soils by solidification processes is an attractive potential remediation process. In this study, the treatability of lead, copper, toluene, and COD was investigated by leaching test. Industrial sand was adopted as the test material and was contaminated with lead copper, and toluene to 100mg/kg, 500mg/kg, 200mg/kg respectively. P solidifying agent was used as the binder(20% by weight of contaminated soil) in the solidification treatment. The leachability of contaminants leached from the solidified soil was evaluated using column test. The percentage of contaminants leached from the solidified soil was significantly reduced by reaction of waste species with cement components and encapsulation reaction of binder. Based on the tests, it is ascertained solidification process can be a very effective method to control the elution of contaminants from the contaminated soil.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 봄 학술발표회 논문집
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• pp.821-826
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• 2003

Laboratory experiments were peformed to understand physical properties of soil-cement column under the influence of acidic flow including metal contaminants and its retaining capacity against metal migration. The contaminant used in this study was nitric acid with Cu and Cd. The Permeability of soil-cement column decreased when pH of the column began to drop below 12. Decreases in pH led to significant reduction of compressive strength of clayey soil-cement specimen, while relatively marginal reduction for sandy soil-cement specimen. The metal contaminants did not leachate from soil-cement column until pH of soil-cement dropped below 7∼8 for Cu and 9∼10 for Cd. Metal contaminants were precipitated and trapped inside the soil-cement column at pHs higher than those mentioned as verified with metal analysis and visual inspection. This indicated that soil-cement column not only performs well as a cut-off wall, but also helps alleviating the level of contamination of the surrounding environment.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 창립총회 및 춘계학술발표회
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• pp.129-132
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• 2000

In this research, we proposed the immobilization zone where the organic contaminant would be fixed, so that ground water could be prevented from the organic contaminants. The surfactant was adsorbed on the soil particles and the organic contaminants were partitioned into the hydrophobic tails of the surfactant in the immobilization zone. Surfactants with different molecular structures-SDDBS (sodium dodecylbenzenesulfonic acid), MADS (monoalkylated disulfonated diphenyl oxide), DADS (dialkylated disulfonated diphenyl oxide) - were used in this study. Up to the present, the research on the immolization simulated the saturated condition. But many site contaminated with organic contaminants and the zones where immobilization would be applied are unsaturated. In this research, in order to investigate the behaviors of surfactants and organic contaminants in unsaturated condition, the unsaturated columns were experimented, and their results were compared with the saturated case.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 봄 학술발표회 논문집
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• pp.597-604
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• 2003

In the soil washing process, the contaminants are usually removed by abrasion from soil particles using mechanical energy and water However, organic contaminants with low water solubility like polycyclic aromatic hydrocarbons (PAH) are remained on soil particles. Previous studies have shown that surfactant possessing amphipathic activity enhances the solubility of organic materials. For this reason solutions with surfactants have been used to improve removal of organic contaminants on soil washing process. But, in this manner, many problems were found like complete loss of surfactants and additional contamination by surfactant. The remediation method using microemulsion has been introduced to overcome these disadvantages. In this case, surfactants are recycled by phase separation of microemulsion after remediation. In microemulsion process, the surfactant will be recycled by phase separation of the microemulsion into a surfactant-rich aqueous phase and an oil phase after extraction. That is why remediation concept applying microemulsion as washing media has been Introduced. Suitable microemulsion have to be used in order to have the chance of refilling the soil after decontamination and to avoid any risk due to toxicity. The purpose of this research is to evaluate effect of microemulsion to remediation of contaminated soil. We performed test with various organic contaminants like Pyrene and BTEX, also compared efficiency of remediation in microemulsion process with soil washing

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권4호
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• pp.90-103
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• 2015

The agricultural soil, meets soil environmental standards whereas agricultural product from the same soil does not meet permissible level of contaminants, is identified in the vicinity of the abandoned mine in Korea. This study estimated the stabilization efficiency of Cd and Pb using limestone through the flood pot test for this kind of agricultural paddy soil. We had the concentration of the monitored contaminants in soil solution for 4 months and analyzed fractionations in soil and concentrations in rice plant. In soil solution of plow layer, the reductive Mn had been detected constantly unlike Fe. The concentrations of Mn in limestone amended soil was relatively lower than that in control soil. This reveals that the reductive heavy metals which become soluble under flooded condition can be stabilized by alkali amendment. This also means that Cd and Pb associated with Mn oxides can be precipitated through soil stabilization. Pb concentrations in soil solution of amended conditions were lower than that of control whereas Cd was not detected among all conditions including control. In contaminants fractionation of soil analysis, the decreasing exchangeable fraction and the increasing carbonates fraction were identified in amended soil when compared to control soil at the end of test. These results represent the reduction of contaminants mobility induced by alkali amendment. The Cd and Pb contents of rice grain from amended soil also lower than that of control. These result seems to be influenced by reduction of contaminants mobility represented in the results of soil solution and soil fractionation. Therefore contaminants mobility (phytoavailability) rather than total concentration in soil can be important factor for contaminants transition from soil to agricultural products. Because reduction of heavy metal transition to plant depends on reduction of bioavailability such as soluble fraction in soil.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권1호
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• pp.67-77
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• 2013

To improve the energy efficiency of conventional thermal treatment, soil remediation with microwave has been studied. In this study, the remediation efficiency of contaminated soil with semi-volatile organic contaminants were evaluated with microwave oven and several additives such as water, formic acid, iron powder, sodium hydroxide (NaOH) solution, and activated carbon. For the experiment, loamy sand and sandy loam collected from Imjin river flood plain were intentionally contaminated with hexachlorobenzene and phenanthrene, respectively. The contaminated soils were treated with microwave facility and the mass removals of organic contaminants from soils were evaluated. Among additives that were added to increase the remediation efficiency, activated carbon and NaOH solution were more effective than water, iron powder, and formic acid. When 10 g of hexachlorobenzene (142.4 mg/kg-soil) or phenanthrene (2,138.8 mg/kg-soil) contaminated soil that mixed with 0.5 g iron powder, 0.5 g activated carbon and 1 ml 6.25 M NaOH solution were treated with microwave for 3 minutes, more than 95% of contaminants were removed. The degradation of hexachlorobenzene during microwave treatments with additives was confirmed by the detection of pentachlorobenzene and tetrachlorobenzene. Naphthalene and phenol were also detected as degradation products of phenanthrene during microwave treatment with additives. The results showed that adding a suitable amount of additives for microwave treatments fairly increased the efficiency of removing semi-volatile soil organic contaminants.

• 한국지반신소재학회논문집
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• 제5권2호
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• pp.1-8
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• 2006

오염토양의 현장정화에 있어서 지반 및 오염물질의 물성치는 정화에 소요되는 시간과 함께 매우 중요한 고려사항이다. Gabr 등(1996)은 연직배수재가 설치된 오염지반에서 시 공간적 변화에 따른 초기오염농도에 대한 오염농도비($C/C_0$)를 구하는 식을 유도하였다. 본 연구에서는 Gabr 등이 유도한 식의 전산모형 FLUSH1을 이용하여 오염지반 흙의 유효입경, 간극률, 형상계수, 밀도, 지반의 온도와 오염물질의 단위중량 및 점성계수가 오염정화에 미치는 영향을 알아보기 위하여 시 공간적 변화에 따른 오염농도비($C/C_0$)를 분석 하였다. 분석결과 연직배수재가 설치된 오염지반에서 정화에 크게 영향을 미치는 인자는 오염지반 흙입자의 유효입경인 것으로 나타났으며, 그 다음으로 오염물질의 점성, 오염지반 흙의 간극율, 형상계수, 지반의 온도, 오염물질의 단위중량, 흙의 밀도 순으로 분석되었다. 오염지반 흙의 밀도는 오염정화에 미치는 영향이 아주 작은 것으로 나타났다.

• Geomechanics and Engineering
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• 제33권3호
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• pp.291-299
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• 2023

Monitoring contaminants in waste landfills on a seabed is important because the leachate affects the marine ecosystem and facility stability. The objective of this study is to optimize a time-domain reflectometry (TDR) probe using different coating materials and several electrodes to estimate contaminants in saline soil. Copper concentrations ranging from 0 mg/L to 10 mg/L were mixed in 3% salinity water to simulate contaminants in the ocean environment. Epoxy, top-coat, and varnish were used as coating materials, and two to seven electrodes were prepared to vary the number and arrangement of the electrodes. Test results showed that the varnish stably captured the increase in copper concentration, while the other coating materials became insensitive or caused leakage current. In addition, a TDR probe with more electrodes exhibited stable and distinct electromagnetic signals. Thus, the TDR probe with seven electrodes coated with varnish was effectively used to estimate contaminants in saline soil.

• 한국환경보건학회지
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• 제22권3호
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• pp.116-122
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• 1996

This study has been focused on the applicability of microwave treatment of soil contaminated by volitile organic chemicals. Substrates studied were sand and sandy soil. These substrates were impregnated with toluene, tetrachloroethylene, o-xylene and p-dichlorobenzene. The microwave treatment was conducted in a modified domestic microwave oven: 2450 MHz, 700 W. The sandy soil temperature added water went up rapidly to about 130$\circ$C for 4 minutes. And then, the temperature appeared to plateau out. A series of tests were performed to depict the effectiveness of microwave treatment technique to organic contaminants from soils. Removal efficiencies in sandy soil and sand were increased with increasing water content and exposure time. Microwave radiation penetrates the soil and heats water throughout the matrix. Therefore, addition of a certain amount of water to the contaminated soil can efficiently enhance the ability of the soil to absorb microwave energy and promote the evaporation of the volitile contaminants. And the vapour pressure of impregnated organic contaminants becomes lower. the removal efficiency becomes poor.