• Journal of the Korean Geosynthetics Society
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• v.5 no.2
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• pp.17-22
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• 2006

This paper presents preliminary field investigations on the electrokinetic (EK) remediation coupled with permeable reactive barrier (PRB) system. unregulated and old-fashioned landfills are one of the primary contributors to various contaminated soil problems. In-situ EK remediation technology has been successfully applied to the environs of unregulated landfill site, located in Kyeong-Ki province, Korea. Atomizing slag was adopted as a PRB reactive material for the remediation of groundwater contaminated with inorganic and/or organic substances. From the preliminary investigations, the coupled technology of EK with PRB system would be effecitve to remeidate contaminated grounds without the extraction of pollutants from subsurface due to the reactions between the reactive materials and contaminants.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1996.09a
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• pp.61-76
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• 1996

본 연구는 하천유역의 중금속을 제거하는데 식물을 활용하기 위해 1994년 7월부터 10월까지 전라북도에 위치한 전주천과 그 주변하천에서 7개 지점을 선정하여 토양층과 물의 Pb, Cu, Zn 및 Fe 등의 함량을 조사하였고 그 주변에 자생하는 고마리, 마름 및 노랑어리연꽃의 중금속 농축량과 부위별 중금속 농축량을 조사하였다. 그리고 재료식물내의 중금속 농축량과 서식지 토양의 중금속 함량과의 관계를 밝히기 위해 재료식물내의 중금속 함유량과 토양의 중금속 함량간의 상관계수를 조사하였다. 실험실 조건하에서 재료식물의 중금속 흡수경향을 조사하기 위해 재료식물 중 고마리를 선정하여 Pb, Cu 및 Zn 등을 여러 농도로 처리한 용액에 고마리의 뿌리부분을 침수하여 재배한 후 그농축량을 측정하였고, 그 결과를 7개 채집지에서 자생한 고마리의 중금속 농축량의 측정치와 비교 분석하였다. 7개 채집지에서 자생한 고마리의 부위별 중금속 농축량은 Pb와 Zn의 경우 줄기<잎<뿌리의 순서로 증가하였고 Cu와 Fe는 잎<줄기<뿌리의 순서로 증가하였으며, 중금별 농축량은 Pb$\leq$Zn의 순서로 증가하였다. 고마리의 배양 실험 결과, 서식지에서 조사된 결과인 잎과 줄기에서 Pb

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.167-174
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• 2004

Several metalliferous and coal mines, including Myungjin, Seojin and Okdong located at the upper watershed of Okdong stream, were abandoned or closed since 1988 due to the mining industry promotion policy and thus disposed an enormous amount of mining wastes without a proper treatment facilities, resulting in water pollution in the downstream areas. AMD and waste effluents from the closed coal mines were very strongly acidic showing pH ranges of 2.7 to 4.5 and had a high level of total dissolved solid (TDS) showing the ranges of 1,030 to 1,947 mg/L. Also heavy metal concentrations in these samples such as Fe, Cu, Cd and anion such as sulfate were very high. These parameters of AMD and effluents were considered to be highly polluted as compared to those in the main stream area of the Okdong river and be major pollutants for water and soil in tile downstream area. Pollution indices of the surface water at the upper stream of Okdong river where AMD of the abandoned coal mines was flowed into main stream were in the ranges of 16.3 to 47.1. On the other hand, those at the mid stream where effluents from tailing dams and coal mines flowed into main stream were in tile ranges of 10.6 to 19.5. However, those at the lower stream were ranged from 10.6 to 14.9 These results indicated that mining wastes such as AMD and effluents from the closed mines were tile major source to water pollution at the Okdong stream areas.

• Journal of Soil and Groundwater Environment
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• v.18 no.3
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• pp.73-81
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• 2013

Various remediation methods have been applied to clean soils contaminated with pollutants. They remove contaminants from the soils by utilizing physicochemical, biological, and thermal processes and can satisfy soil remediation standards within a limited time; however, they also have an effect on the biological functions of soils by changing soil properties. In this study, changes of the biological properties of soils before and after treatment with three frequently used remediation methods-soil washing, land farming, and thermal desorption-were monitored to investigate the effects of remediation methods on soil biological functions. Total microbial number and soil enzyme activities, germination rate and growth of Brassica juncea, biomass change of Eisenia andrei were examined the effects on soil microorganisms, plant, and soil organisms, respectively. After soil washing, the germination rate of Brassica juncea increased but the above-ground growth and total microbial number decreased. Dehydrogenase activity, germination rate and above-ground growth increased in both land farming and thermal desorption treated soil. Although the growth of Eisenia andrei in thermal desorption treated soil was higher than any other treatment, it was still lower than that in non-contaminated soil. These results show that the remediation processes used to clean contaminated soil also affect soil biological functions. To utilize the cleaned soil for healthy and more value-added purposes, soil improvement and process development are needed.

• Journal of the Korean Society of Hazard Mitigation
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• v.1 no.3 s.3
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• pp.83-92
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• 2001

Field investigations for subsurface soil and groundwater at a gas station showed that the site was severely contaminated and even petroleum compounds as free liquid state were observed. Pilot-scale soil flushing and soil vapor extraction process(SVE) were applied to evaluate the effectiveness of pollutants removal. Surfactant solution, Tween 80, was used to enhance the solubility of petroleum compounds and resulted in about 10 times increase on TPH(Total Petroleum Hydrocarbon) concentration. As for SVE method, maximum concentration of TPH and BTEX reached within 24 hours of extraction and then continuously decreased. Considerations on the groundwater level and the kinetic limitation for volatilization of contaminants have to be taken into account for the effective application of SVE process.

• Journal of Soil and Groundwater Environment
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• v.16 no.2
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• pp.12-29
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• 2011

Risk-based screening levels (RBSLs) of some pollutants for residential adults were derived with risk assessment tools developed by United States Environmental Protection Agency (USEPA), American Society for Testing and Materials (ASTM), and Korea Ministry of Environment (KMOE) and compared each other. To make the comparison simple, ingestion of soil, dermal contact with soil, outdoor inhalation of vapors, indoor inhalation of vapors, and inhalation of soil particulates were chosen as exposure pathways. The results showed that the derived RBSLs varied for every exposure pathway. For direct exposure pathways (i.e., ingestion of soil and dermal contact with soil), the derived RBSLs varied mainly due to the different default values for exposure factors and toxicity data. When identical default values for the parameters were used, the same RBSLs could be derived regardless of the assessment tools used. For inhalation of vapors and inhalation of soil particulates, however, different analysis methods for cross-media transfer rates were used and different assumptions were established for each tool, identical RBSLs could not be obtained even if the same default values for exposure factors were used. Especially for inhalation of soil particulates pathway, screening level derived using KMOE approach (most conservative) was approximately 5000~10000 times lower than the screening level derived using ASTM approach (least conservative). Our results suggest that, when deriving RBSL using a specific tool, it is a prerequisite to technically review the analysis methods for cross-media transfer rates as well as to understand how the assessment tool derives the default values for exposure factors.

• Journal of Soil and Groundwater Environment
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• v.8 no.2
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• pp.87-91
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• 2003

This study was carried out to investigate the heavy metal distributions of soils in the vicinity of Shi-Hwa industrial complex region, where the air pollutants from industrial area could affect the soil environment of near residential and green areas. The ranges of contents of As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn in soils were 0.58~3.81, ND~0.91, 0.15~6.33, ND~l.86, 0.14~110.27, ND~l.17, 0.04~10.59, 1.16~86.48 and 1.83~212.65 mg/kg, respectively. For all industrial, residential and green areas, the heavy metal contents were much lower than the standard of Korean Soil Environmental Preservation Act or the critical concentration which phytotoxicity is considered to be possible. Mean values of contents of As were similar in industrial, residential and green areas. However, the mean values of contents of Cd and Cr in industrial area were higher 10 and 5 times than those in residential and green area, respectively. And also the mean values of contents of Co, Cu, Hg, Ni, Pb and Zn in industrial area were higher 2~3 times than those in residential and green area.

• Economic and Environmental Geology
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• v.30 no.4
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• pp.327-340
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• 1997

Geochemical characteristics of groundwater, based on chemical analyses of 54 water samples, differ among main rocks of Haman formation, Panyawoel formation, andesite and granite in Daegu area in relation to mineralogical and chemical compositions of the rocks. Concentrations of most solutes are higher in groundwaters of Haman and Panyawoel formations than in those of andesite and granite. High concentrations of $Ca^{2+}$ and $Mg^{2+}$ in groundwaters of the sedimentary rocks result mainly from reaction of $CO_2$-charged water with calcite and weathered feldspars. Average groundwaters in the sedimentary rocks are oversaturated with respect to calcite. Major types of groundwaters are hard $Ca(HCO_3)_2$ and $CaSO_2-CaCl_2$ with hardness of 442 mg/l for Haman formation and 275 mg/l for Panyawoel formation whereas they are soft $Ca(HCO_3)_2$ with hardness 35 mg/I for andesite and 39 mg/I for granite. $Ca(HCO_3)_2$ type results mainly from calcite-dissolution and $CaSO_4-CaCl_2$ from pyrite and partly from domestic pollutants. $CaSO_4-CaCl_2$ type may indicate that groundwaters in the sedimentary rocks are more evolved geochemically than those in the igneous rocks, but it is not obvious because the type might be affected by pyrie dissolution and domestic pollutions. Acid rain is buffered by active calcite in the sedimentary rocks. In the igneous rocks acid rain might react with gibbsite and other forms of $Al(OH)_3$ that might have accumulated as weathering products of primary silicates, and is buffered.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1998.06a
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• pp.99-107
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• 1998

전 세계에서 다양한 환경 매체를 통해 광범위하게 검출되고 있는 대표적 환경오염물질 (environmental pollutants)인 polychlorinated biphenyls(PCBs)의 국내 4대강 주요 하천 저니토양과 모공단 하천수 및 저니토중 오염도를 각 congener별로 또는 총량으로서 GC/MS 를 사용하여 정량하였다. 그 결과 4대강의 주요 지천중 낙동강의 사상공단근처의 저니토에서 총 PCBs가 가장 높은 290.87$\mu\textrm{g}$/kg이었고 한강의 왕숙천도 비교적 높은 221.l1$\mu\textrm{g}$/kg이었다. 모공단 하천수 및 저니토 중 PCBs를 분석한 결과 전 시료에서 검출되었으며 하천수 및저니토에서의 총 PCBs 농도(mean$\pm$S.D.)는 0.1069$\pm$0.0179$\mu\textrm{g}$/L 및 908.80$\pm$462.30$\mu\textrm{g}$/kg였으며, 이때 저니토에서의 농축계수는 0.85$\times$$10^4$였다. 저니토중 총 유기물함량과 저니토중 PCBs 잔류량의 조사에서 서로간 상관관계 (상관계수=0.7084)가 있음을 알 수 있었으나 PCBs 배출원에 의한 영향이 커서 정확한 상관관계를 얻기가 어려웠다. Congener-specific analysis에 의해 하천수 및 저니토 시료에서 공통적으로 검출된 대표적 congener는 52, 95, 101, 99,87, 110, 118, 149, 153, 138, 180 였다. 본 연구결과 하천수에서는 triCBs와 tetraCBs 가 비교적 높은 농도로 검출되었던 반면 저니토에서는 hexaCBs 및 heptaCBs가 다른 poylCBs에 비해 비교적 높은 농도로 검출되었다. 이상의 연구결과를 통해 모공단 하천수 및 저니토가 PCBs에 의해 심하게 오염되어 있음을 알 수 있고 국내의 주요 하천의 경우도 계속적인 모니터링이 필요함을 알 수 있다.

• Journal of Soil and Groundwater Environment
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• v.23 no.6
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• pp.104-113
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• 2018

A three-dimensional electrochemical process using nanosized zero-valent iron (NZVI)/activated carbon (AC) particle electrode and persulfate (PS) was developed for oxidizing pollutants. X-ray diffraction (XRD), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), and Brunauer-Emmett-Teller (BET) surface area analysis were performed to characterize particle electrode. XRD and SEM-EDS analysis confirmed that NZVI was impregnated on the surface of AC. Compared with the conventional two-dimensional electrochemical process, the three-dimensional particle electrode process achieved three times higher efficiency in phenol removal. The system with current density of $5mA/cm^2$ exhibited the highest phenol removal efficiency among the systems employing 1, 5, and $10mA/cm^2$. The removal efficiency of phenol increased as the Fe contents in the particle electrode increased. The particle electrode achieved more than 70% of phenol removal until it was reused for three times. The sulfate radical played a predominant role in phenol removal according to the radical scavenging test.