• Geotechnical Engineering
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• v.11 no.4
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• pp.87-98
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• 1995

Laboratory tests were performed on modeling of in situ remediation of contaminated soils by aqueous solution extraction, thus investigating the feasibility of in situ treatments of soil to promote desorption of organic hazardous wastes. The investigation was conducted using phenol, aniline, quinoline, and 2-napthol adsorbed onto a UH40 soil, and various aqueous solutions were used to desorb, or otherwise remove, these organic contaminants. Decontaminants consisted of deionized water as a reference, hydrogen peroxide, acidy, bases, and surfactants. In situ conditions were modeled in the laboratory by permeating potential extracting liquids through reconstituted, contaminated soil specimens under controlled hydraulic gradients and stress condition through flexible wall permeameter tests. Sodium hydroxide desorbed phenol effectively. Aniline was effectively descorbed by nonionic surfactant. Anionic surfactant remediated quinoline and 2-napthol.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.431-437
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• 2000

The aim of the work described in this paper is to develope a pavement method for farm road. To this ends, a series of material test are conducted on in-situ soil which was mixed additives-coarse aggregate, polypropylene fiber, excellent soil compound etc. With the laboratory test results, in-situ pavement test was conducted during two years. The serious problem of the pavement is not appeared up to this time. And the measurement of field data is continued presently. The majority merits of this pavement method is low cost and using environmental materials.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.740-747
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• 2015

This research was performed to evaluate the feasibility of in situ soil flushing for TPH-contaminated soil remediation. It was conducted in batch test as fundamental research for in situ soil flushing. The 30% of initial TPH concentration was removed by shaking only in batch test. The removal efficiency of TPH in case of groundwater as surfactant dilution solution was approximate 2~6% lower than that of distilled water. Mixing ratio of soil to surfactant solution did not practically effect on the TPH removal efficiency. In the experiment of using single or mixed surfactant solution with 0.1~4.0 wt%, Tween-80, SWA-1503, SWA-1503+SDS showed averagely over 80%. It was determined that the optimum surfactant concentration was 0.1 wt% because there was no significant difference between concentrations of 0.1~4.0 wt%.

• Journal of Life Science
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• v.22 no.6
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• pp.723-729
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• 2012

Filter plate microbial trap (FPMT) was invented as an in situ cultivation device for the isolation of bacteria from natural environments. FPMT consists of a medium and membrane filters (0.45 ${\mu}m$ pore size) and microorganisms and compounds can be moved freely moved into the medium. This device was applied to two soil samples of Greenland. The microbial diversity of both soil samples by FPMT was higher than that by the conventional Petri dish-based method. Moreover, novel bacterial species were isolated by FPMT. The new FPMT is effective for in situ cultivation of natural samples and could be applicable to the isolation of uncultivable microorganism.

• Geomechanics and Engineering
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• v.6 no.5
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• pp.487-502
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• 2014

A three dimensional finite element model was used to simulate rapid impact compaction (RIC) in loose granular soils using ABAQUS software for one impact point. The behavior of soil under impact loading was expressed using a cap-plasticity model. Numerical modeling was done for a site in Assalouyeh petrochemical complex in southern Iran to verify the results. In-situ settlements per blow were compared to those in the numerical model. Measurements of improvement by depth were obtained from the in-situ standard penetration, plate loading, and large density tests and were compared with the numerical model results. Contours of the equal relative density clearly showed the efficiency of RIC laterally and at depth. Plastic volumetric strains below the anvil and the effect of RIC set indicated that a set of 10 mm can be considered to be a threshold value for soil improvement using this method. The results showed that RIC strongly improved the soil up to 2 m in depth and commonly influenced the soil up to depths of 4 m.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.334-337
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• 2003

This study was carried out to investigate the effect of soil properties, such as soil organic matter(SOM) content and water content on die-off and regrowth of indigenous microbes due to in-situ ozonation. Four different soils were collected and the soil samples applied to different ozonation time(0-360 min) were incubated during 4 weeks. Population of the indigenous microbes was monitored during incubation period. The number of indigenous microbes in all samples dramatically decreased (more than 90%) within 30 minutes of ozone injection. With increased ozonation time by 360 minutes, the number of the indigenous microbes decreased by 99.99% in all samples. Die-off of the indigenous microbes due to ozone treatment was inversely proportional to SOM and water content. Especially, sample 3 and Sample 4 containing relatively high SOM content and water content showed high regrowth rate, and this resulted from the increase of water soluble and biodegradable organic fraction in soil water after ozone treatment. Soil sample ozonated for 360 minutes showed minor increase in microbial population during 4 weeks of incubation period.

• Geomechanics and Engineering
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• v.5 no.4
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• pp.313-329
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• 2013

Vetiver grass (Vetiveria zizanioides) is being effectively used in many countries to protect embankment and slopes for their characteristics of having long and strong roots. In this paper, in-situ shear tests of the ground with the vetiver roots have been conducted to investigate the stabilization properties corresponding to the embankment slopes. Numerical analyses have also been performed with the finite element method using elastoplastic subloading $t_{ij}$ model, which can simulate typical soil behavior. It is revealed from field tests that the shear strength of vetiver rooted soil matrix is higher than that of the unreinforced soil. The reinforced soil with vetiver root also shows ductile behavior. The numerical analyses capture well the results of the in-situ shear tests. Effectiveness of vetiver root in geotechnical structures-strip foundation and embankment slope has been evaluated by finite element analyses. It is found that the reinforcement with vetiver root enhances the bearing capacities of the grounds and stabilizes the embankment slopes.

• Journal of Soil and Groundwater Environment
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• v.7 no.4
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• pp.77-86
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• 2002

Surfactant enhanced in-situ soil flushing was performed to remediate the soil and groundwater at an oil contaminated site, where had been used as a military vehicle repair area for 40 years. A section from the contaminated site (4.5 m $\times$ 4.5 m $\times$ 6.0 m) was selected for the research, which was composed of heterogeneous sandy and silt-sandy soils with average $K_d$ of 2.0$\times$$10^{-4}$cm/sec. Two percent of sorbitan monooleate (POE 20) and 0.07% of iso-prophyl alcohol were mixed for the surfactant solution and 3 pore volumes of surfactant solution were injected to remove oil from the contaminated section. Four injection wells and two extraction wells were built in the section to flush surfactant solution. Water samples taken from extraction wells and the storage tank were analyzed on a gas-chromatography (GC) for TPH concentration in the effluent with different time. Five pore volumes of solution were extracted while TPH concentration in soil and groundwater at the section were below the Waste Water Discharge Limit (WWDL). The effluent TPH concentration from wells with only water flushing was below 10 ppm. However, the effluent concentration using surfactant solution flushing increased to 1751 ppm, which was more than 170 times compared with the concentration with only water flushing. Total 18.5 kg of oil (TPH) was removed from the soil and groundwater at the section. The concentration of heavy metals in the effluent solution also increased with the increase of TPH concentration, suggesting that the surfactant enhanced in-situ flushing be available to remove not only oil but heavy metals from contaminated sites. The removal efficiency of surfactant enhanced in-situ flushing was investigated at the real contaminated site in Korea. Results suggest that in-situ soil flushing could be a successful process to remediate contaminated sites distributed in Korea.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1997.05a
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• pp.53-56
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• 1997

오염된 토양의 복원기술 개발의 일환으로 폐수의 처리 등에 많이 이용되어온 Fenton-like oxidation을 petroleum으로 오염된 토양의 in-situ/ex-situ remediation을 위한 data 축적을 위해 실험실상에서 적용하여 보았다. 천연 토양속에 흔히 존재하는 철광석의 한 형태인 magnetite, goethite를 이용해 Fenton-like oxidation을 유도하여 silica sand에 오염된 kerosene의 분해를 잔존 TPH의 분석을 통하여 확인하였다. 초기 kerosene의 농도, 과수의 농도, 철광석의 양을 변수로 하여 최적 처리조건을 구하기 위한 실험을 진행하였다.

• Journal of Soil and Groundwater Environment
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• v.22 no.1
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• pp.18-26
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• 2017

In a previous study, we assessed the feasibility of ferric chloride ($FeCl_3$) as a washing agent in bench-scale in-situ soil washing to remove Pb from agricultural paddy soil. Herein is a subsequent study to evaluate variations in soil properties after $FeCl_3$ soil washing in terms of fractionation and bioavailability of Pb and chemical properties of the soil. After soil washing, the soil pH decreased from 4.8 to 2.6 and the exchangeable fractions of Pb in the soil increased from 12 mg/kg to 15 mg/kg. Variations in the Pb fractionation of the soil increased Pb bioavailability by almost three-fold; however,the base saturation decreased by 75%. The concentrations of total nitrogen and available phosphate were similar before and after soil washing. The available silicate concentration significantly increased after soil washing but was two times lower than that of soil washed with HCl, which is widely used as a washing agent. This indicates that $FeCl_3$ can be an acceptable washing agent that protects the soil clay structure. The results suggest that soil amendment, such as liming, is needed to recover soil pH, reduce mobility of Pb, and provide exchangeable bases of Ca, Mg, and K as essential elements for the healthy growth of rice plants in reused soil that has been washed.