• Journal of the Korean Geotechnical Society
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• v.19 no.6
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• pp.325-334
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• 2003

It is very difficult to rehabilitate the damaged earth dam core to manage it stably against development of flow path and increase of leakage by hydraulic fracture. In this study, application of CGS (Compaction Grouting System) to damaged earth dam core was noticed by analyzing and comparing the results of the in-situ data and FEM. Results of in-situ data showed that according as progress of rehabilitation works tip pressures increased and volume of injection decreased, voids of damaged dam core were filled with materials similar to origin dam core. Rehabilitations caused turbidity and volume of leakage to decrease at the same water level. Also, results of FEM analysis indicated that permeability decreased by rehabilitation. Through this study, it is proved that CGS is able to decrease permeability coefficient, volume of leakage and turbidity on damaged earth dam core.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.1
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• pp.245-257
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• 2013

Lately, besides promoting the biodiversity of the natural ecosystems, there is a demand for climate change mitigation features that will reduce greenhouse gases and prevent disasters that will bring damages such as torrential rains. However, there was not a lot of discussion on the soils that are key in these features. Therefore, this paper proposes a network (Gold Network) as an alternative that will solve the problem that was filed earlier by figuring out how to compose the soil environment. First, in order to maximize the ecological status and value of the soil, a soil network can be proposed through the vertical and horizontal connections of the fragmented soil. Second, there is a need to understand and research the organic system of the ecosystems as well as the complex perspective of the ecosystem services, not only the fragmentary perspectives of the soil remediation, planting improvements or the other existing elements. Third, there is a need to apply the integrated perspective of the Landscape Ecology, Ecological Engineering and Restoration Ecology for the connectivity of the soil (network) due to it being in the execution of the soil network. If a soil network was to be built, a fundamental ecological network would be realized to not only promote biodiversity but also to prepare effective adaptation to climate change.

• Journal of Korean Society on Water Environment
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• v.25 no.4
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• pp.522-529
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• 2009

To supply safe drinking water to areas lacking in water supply and drainage system, such as rural area and military bases in proximity to Demilitarized Zone, effective method for treating organic contaminants such as MTBE is required. This study focuses on seeking optimal conditions for effective degradation of MTBE using a bath type ultrasound reactor. Effectiveness of MTBE degradation by ultrasound is dependent on the frequency, power, temperature, treatment volume, initial concentration, catalyst, etc. In this study the degradation rate of MTBE by ultrasound was proportional to power/unit volume ratio and removal is relatively more efficient for 0.1 mM than for 1 mM of MTBE solution. Efficiency of ultrasound treatment for 1 mM MTBE solution was enhanced under bath temperature of $30^{\circ}C$ compared to $4^{\circ}C$, but the temperature effect was negligible for 0.1 mM MTBE solution. Also for 0.1 mM MTBE solution, effect of catalyst such as $TiO_2$ and $Fe^0$ on treatment speed was negligible, and zeolite even increases the time taken for the degradation. Under these specific experimental conditions of this study, the most determinant factor for degradation rate of MTBE in solution was frequency and power of ultrasound. The results have shown that a continuous ultrasound reactor system can be used for small scale remediation of organically polluted groundwater, under optimal conditions.

• Journal of Soil and Groundwater Environment
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• v.28 no.5
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• pp.59-67
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• 2023

This review examined the current administrative policies and guidelines for management of reclaimed soils after remediation processes and proposed practical strategies to improve the potential value of the remediated soil as a resource. Three management practices are proposed to facilitate more efficient recycling of remediated soil; obligatory use, quality certification, and tracking of the remediated soils. If properly implemented in utilization of remediated soil, these strategies could contribute to enhancing public safety by assuring soil quality. Such administrative tools, for both suppliers and demanders, are expected to mitigate potential risks associated with the transactions of remediated soil. To enhance the quality assurance process, a soil quality certification combined with the soil health assessment index was proposed. The systematic integration of the suggested practices with soil health assessment can allow to produce optimal results, encompassing affordability, efficiency, and accessibility, which helps establishing more robust 'Remediated Soil Recycling Management System (RSRMS)'. Subsequent researches should be conducted to develop more effective policies that incorporate soil health assessment tools. The proposed management practices for remediated soil, coupled with soil health assessment, can be a pioneering effort to achieve such goals. By fostering an environmentally friendly policies, the sustainable utilization of remediated soil can be attained. Overall, the proposed strategies can provide a sound framework for responsible and sustainable soil management practices.

• The Journal of Engineering Geology
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• v.19 no.3
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• pp.295-306
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• 2009

The risk assessment of groundwater and soil in Sasang industrial complex in Busan Metropolitan City was carried out in order to estimate risks to human health and the environment. The carcinogenic risk (CR) of receptors to soil and air was not identified. However, the CRs for TCE and PCE were 6.7E-6 and 1.0E-5, respectively. Hazard quotient (HQ) and hazard index (HI) did not appear through air exposure pathways. Yet the HQ and HI of soil were 3.4E-5 and 5E-5, respectively, and lower than the critical value (1.0). On the contrary, HQ and HI with respect to groundwater were calculated as 0.7 (not hazardous) and 1.4 (hazardous). The constituent reduction factor (CRF) for TCE in the study area was determined as 2.5, and thus remediation work is demanded. As a result of sensitivity analysis for 18 exposure factors, eight exposure factors (life time of carcinogens, age, body weight, exposure duration, exposure frequency, dermal exposure frequency, water ingestion rate, and soil ingestion rate) varied with the variation of risk.

• Journal of Soil and Groundwater Environment
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• v.12 no.3
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• pp.44-52
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• 2007

Contaminated sediments more than 30 million/$m^3$ is generated from dredging work for harbours and coastal maintenance in Korea. Approximately 300 million/$m^3$ of sediments is dredged to deepen harbours and shipping lanes in US and of which $3{\sim}12million/m^3$ is highly contaminated. Although much is known about technologies for the remediation of heavy metal contaminated soil, much less is known about the treatment of contaminated sediment. In general, negatively charged fine particles will migrate towards positively charged system of electrodes under the influence of electrophoresis. However, the electrically induced migration of colloidal particles contaminated with heavy metals may be hindered by the positively charged heavy metal contaminants adsorbed onto the soil surfaces depending on the contamination level. This paper demonstrates settling behaviour of clayey soil by comparison with electrophoretic particle movement under the effects of heavy metal contamination, applied electric field strength, and its polarity changed by the electrode configuration.

• Journal of Korea Soil Environment Society
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• v.4 no.3
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• pp.85-93
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• 1999

The destruction of hazardous chemicals such as chlorinated organic compounds(COCs) and nitroaromatic compounds(NACs) by zero-valent iron powder is one of the latest innovative technologies. In this paper. the rapid dechlorination of chlorinated compounds as well as transformation of nitro functional group to amine functional group in the nitroaromatic compounds using synthesized zero-valent iron powder with nanoscale were studied in anaerobic batch system. Nanoscale iron, characterized by high surface area to mass ratios(31.4$\textrm{m}^2$/g) and high reactivity, could quickly reacts with compounds such as TCE, chloroform, nitrobenzene, nitrotoluene, dinitrobenzene and dinitrotoluene, at concentration of 10mg/L in aqueous solution at room temperature and pressure. In this study, the TCE was dechlorinated to ethane and chloroform to methane and nitro groups in NACs were transformed to amino groups in less than 30min. These results indicated that this chemical method using nanoscale iron powder has the high potential for the remediation of soils and groundwater contaminated with hazardous toxic chemicals including chlorinated organic compounds and nitro aromatic compounds.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.11
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• pp.1555-1565
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• 2009

Anaerobic rumen fungi have been regarded as good genetic resources for enzyme production which might be useful for feed supplements, bio-energy production, bio-remediation and other industrial purposes. In this study, an expressed sequence tag (EST) library of the rumen anaerobic fungus Neocallimastix frontalis was constructed and functional genes from the EST library were analyzed to elucidate carbohydrate metabolism of anaerobic fungi. From 10,080 acquired clones, 9,569 clones with average size of 628 bp were selected for analysis. After the assembling process, 1,410 contigs were assembled and 1,369 sequences remained as singletons. 1,192 sequences were matched with proteins in the public data base with known function and 693 of them were matched with proteins isolated from fungi. One hundred and fifty four sequences were classified as genes related with biological process and 328 sequences were classified as genes related with cellular components. Most of the enzymes in the pathway of glucose metabolism were successfully isolated via construction of 10,080 ESTs. Four kinds of hemi-cellulase were isolated such as mannanase, xylose isomerase, xylan esterase, and xylanase. Five $\beta$-glucosidases with at least three different conserved domain structures were isolated. Ten cellulases with at least five different conserved domain structures were isolated. This is the first solid data supporting the expression of a multiple enzyme system in the fungus N. frontalis for polysaccharide hydrolysis.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1997.05a
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• pp.17-20
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• 1997

이 연구에서는 국내에 산재되어 있는 금속광산들에 대한 토양환경오염을 조사하고 적절한 환경처리를 위한 기초자료를 제공하기 위하여 대표적인 연-아연광산, 동광산 및 금-은광산을 대상으로 As. Cd, Cu, Pb, Zn 등의 오염규모와 분산정도를 규명하고자 하였다. 연구대상지역으로 삼보 연-아연강산, 달성 동-텅스텐광산 그리고 구봉, 삼광, 금왕 금-은광산을 선정하여 이들 광산 주변에서 토양을 채취하여 화학분석을 실시하였다. 그리고 연속추출법을 이용하여 토양중에 존재하는 중금속의 존재형태를 규명하였으며 화학분해방법에 따른 중금속의 추출정도를 고찰하기 위하여 강산을 이용한 분해방법과 토양환경보전법에 제시된 방법을 비교하였다. 화학분석 결과, 삼보광산 주변의 상부토양 (0-15cm 심도)에서는 평균 11.8 $\mu\textrm{g}$/g Cd, 208 $\mu\textrm{g}$/g Cu, 2,700 $\mu\textrm{g}$/g Pb, 8,300 $\mu\textrm{g}$/g Zn이 검출되었으며 일부 농경지에서는 토양환경보전법의 우려기준을 초과하는 중금속이 검출되어 광산활동에 의한 토양오염이 심각함이 조사되었다. 달성광산 주변 토양에서도 다량의 중금속이 검출되었으며 (평균 4.4 $\mu\textrm{g}$/g Cd, 1,950 $\mu\textrm{g}$/g Cu, 1,030 $\mu\textrm{g}$/g Pb, 419 $\mu\textrm{g}$/g Zn) 특히 As (평균 2,500 $\mu\textrm{g}$/g)의 오염이 심각하였다. 그리고 대표적인 금은광산인 구봉, 삼광 및 금왕광산에서는 광미와 선광장 주변에서 다량의 중금속과 As가 검출되었다. 이 연구 결과, 이들 점오염원에 대한 오염정도가 심각하므로 이를 적절하게 처리할 수 있는 오염복구사업이 실시되어야할 것으로 판단된다.

• Journal of the Korean GEO-environmental Society
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• v.15 no.11
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• pp.13-19
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• 2014

Permeable reactive barrier has been recognized as the one of representative methods for remediation of contaminated groundwater. Reactive barrier system containing two and more reactive materials can remove multiple contaminants such as nutritive salts and heavy metals. In this study, removal efficiency of multiple contaminants was evaluated when both zeolite and basic oxygen furnace slag were used as reactive materials. Sequential batch test which consists of two materials was performed to evaluate removal efficiency comparing the reaction order of them against nutritive slats including ammonium and phosphate and heavy metal including cadmium. As a result, zeolite-basic oxygen furnace slag sequence batch test showed the best efficiency for removal of multiple contaminants including nutritive salts and heavy metal.