• 한국지하수토양환경학회지:지하수토양환경
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• 제20권1호
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• pp.1-6
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• 2015

The objectives of this study were to calculate the radius of influence (ROI) of well for an air-sparging (AS)/soil vapor extraction (SVE) system and to evaluate the applicability of the system applied for the remediation of the petroleum contaminated rail site. For air permeability test, three monitoring wells were installed at a location of 1.3 m, 2.3 m, 3.0 m from the extraction well. And the pressure of each monitoring well was measured by extracting air from the extraction well with the pressure and flow of $(-)2,600mmH_2O$ and $1.58m^3/min$. The ROI for an extraction well was calculated as 4.31 m. Air was injected into the injection well with the pressure and flow of $3,500mmH_2O$ and $0.6m^3/min$ to estimate the radius of influence for oxygen transfer. Oxygen concentrations of air from three monitoring wells were measured. The ROI of an injection well for oxygen transfer was calculated as 3.46 m. The 28 extraction wells and 19 injection wells were installed according to the ROI calculated. The AS/SVE system was operated eight hours a day for five months. The rail site was contaminated with the petroleum and concentrations of benzene, toluene, and xylene were over the 'Worrisome Standard' of the 'Soil Environment Conservation Act'. The contaminated area was estimated as $732m^2$ and contaminants were dispersed up to (-)3 m from the ground. During the operation period, soil samples were collected from 5 points and analyzed periodically. With the AS/SVE system operation, concentrations of benzene, toluene, and xylene were decreased from 7.5 mg/kg to 2.0 mg/kg, from 32.0 mg/kg to 23.0 mg/kg, from 35.5 mg/kg to 23.0 mg/kg, respectively. The combined AS/SVE system applied to the rail site contaminated with volatile organic compounds (VOCs) exhibited a high applicability. But the concentration of contaminants in soil were fluctuated due to the heterogeneous of soil condition. Also the effect of the remediation mechanisms was not clearly identified.

• 환경위생공학
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• 제13권3호
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• pp.102-112
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• 1998

The fate of polynuclear aromatic hydrocarbons(PAMs) in soil has drawn increasing concern due to their toxic, carcinogenic, and mutagenic effects. These compounds have been most commonly carried into the soil in solvent, as in a coal tar or cresote. This study has been focused on the applicability of microwave treatment of soils contaminated by PAHs. Studies have been conducted with soil(particle diameter $150~500{\mu}m$), which was spiked with naphthalene, acenaphthene, fluorene, anthracene and pyrene, with different moisture contents. According to the results of the research, up to 95% removal efficiency of naphthalene was observed in 10% moisturized soil for five minutes microwave inducing And the removal efficiency of acenaphthene and fluorene were observed to be 88.9%, 67.2% in 30% moisturized soil, respectively. Due to the low vapor pressure, anthracene and pyrene showed the low removal efficiency. In case the powdered activated carbon was added to the soil as a sensitizer, anthracene and pyrene were decomposed into a various by-products. Decomposition rates of anthracene and pyrene were increased with incresing addition of a PAC to the soil. It is concluded that the developement of a microwave process to remediate soils contaminated with PAHs is foreseeable. But additional studies are also needed regarding continuous microwave heating process.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.25-39
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• 2003

Risk and exposure assessment for subsurface environment is very important for both aspects of health and environmental protection as well as making decision of remedial goal for engineering activities. Exposure due to hazardous chemicals in the subsurface environment is essential to assess risk lev121 to individual person, especially from soil and groundwater environmental media. In this paper, the status of soil and groundwater contamination is presented to discuss on the problem for environmental risk assessment. The methodologies of fate and exposure models are also discussed by conducting the case studies of exposure assessment for heavy metals, organic compounds, and dioxin compounds. In addition, the structure of exposure models and available data for model calculation are examined to make clear more realistic exposure scenarios and the application to the practical environmental issues. Three kinds of advanced remediation techniques for soil and groundwater contamination are described in this paper, The most practical method for VOCs is the bio-remediation technique in which biological process due to consortium of microorganisms can be applied. For more effective remediation of soil contaminated by heavy metals we have adopted the soil flushing technique and clean-up system using electro-kinetic method. We have also developed the advanced techniques of geo-melting method for soil contaminated by DXNs and PCB compounds. These techniques are planed to introduce and to apply for a lot of contaminated sites in Japan.

• 한국환경농학회지
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• 제31권2호
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• pp.97-103
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• 2012

BACKGROUND: Metal mines were actively developed in the early twentieth century in Korea; however, most of these mines were closed and abandoned without proper management. Therefore, toxic metal contamination in the vicinity of Korean abandoned metal mines has been reported. A risk assessment for these metals was performed for residents near by abandoned Sanyang metal mine. METHODS AND RESULTS: Soil and groundwater samples were collected from May to October 2007 around the mine. After pretreatment of these samples, metal concentrations were measured and then a risk assessment was performed using the Korean soil-contamination risk assessment guidelines. Cancer risk was the highest from inhalation of Pb-contaminated soil, followed in descending order by As-contaminated soil inhalation and water ingestion. The sum of carcinogenic risks was $3.35{\times}10^{-3}$. The noncarcinogenic risk was observed for inhalation of Hg-contaminated soil (5.71). CONCLUSION: Inhalation of soil in dust was the principal pathway to cause the health risk and most of the risk was attributed to As, Pb,Cd, and Hg contamination.

• 자원환경지질
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• 제54권4호
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• pp.483-494
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• 2021

본 연구에서는 폐금속광산과는 달리 우려기준 전후의 낮은 비소 오염농도 분포특성을 가지는 폐석탄광산 농경지 토양을 대상으로 광해방지사업(토양개량·복원사업) 시 복토층의 두께 감소 가능여부를 벼를 식재한 담수형 컬럼실험을 통해 검토하였다. 담수 후 4개월 동안 토양용액의 pH, EC, ORP 및 무기원소(Fe, Mn, Ca, As) 농도를 모니터링한 결과 컬럼하층에서 상층으로 미치는 영향은 높지 않은 것으로 나타났다. 복토 두께에 따른 비교에서도 하층의 영향보다는 복토층 두께 변화에 따른 ORP 변화가 복토재 무기원소의 거동에 영향을 미치는 결과를 보였다. 이러한 결과는 토양용액의 거동이 상하층간 반응의 영향보다는 각 층별 나타나는 토양의 이질성에 우선하여 나타난 것으로 판단되었다. 모니터링 종료시점에서 채취한 벼 뿌리의 비소 농도는 현행 사업 조건과 같은 40 cm 두께의 복토층을 조성한 경우 컬럼하층의 안정화 처리여부에 상관없이 대조구 대비 98%가 감소되었다. 20 cm 두께의 복토층에서는 오염토의 안정화가 없을 경우 58%, 안정화처리 시 80%의 전이감소 효율을 나타내었다. 따라서 오염 농경지 토양에 대한 적정 안정화 처리를 수행할 경우 복토재의 사용량을 감소시킬 수 있으며, 경제적인 사업수행효과도 이룰 수 있을 것으로 판단된다.

• Journal of Ecology and Environment
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• 제32권4호
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• pp.267-275
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• 2009

To investigate the possible applications of plants to remediate heavy-metal-contaminated soil, a pilot experiment was performed for four years in a reclaimed dredging area using two Alnus species, i.e., Alnus firma and Alnus hirsuta. In a comparison of phytomass of the two species at two different planting densities, the phytomass of Alnus planted at low density was twice as high as that of Alnus planted at high density after four years. The Alnus species showed active acclimation to the heavy-metal-contaminated soil in a reclaimed dredging area. A. hirsuta showed greater accumulation of phytomass than A. firma, indicating that it is the better candidate for the phytoremediation of heavy-metal-contaminated soils. In the pilot system, Alnus plants took metals up from the soil in the following order; Pb > Zn > Cu > Cr > As > Cd. Uptake rates of heavy metals per individual phytomass was higher for Alnus spp. planted at low density than those planted at high density in the pilot system. Low plant density resulted in higher heavy metal uptake per plant, but the total heavy metal concentration was not different for plants planted at low and high density, suggesting that the plant density effect might not be important with regard to total uptake by plants. The quantity of leached heavy metals below ground was far in excess of that taken up by plants, indicating that an alternative measurement is required for the removal of heavy metals that have leached into ground water and deeper soil. We conclude that Alnus species are potential candidates for phytoremediation of heavy-metal- contaminated surface soil in a reclaimed dredging area.

• 한국지하수토양환경학회지:지하수토양환경
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• 제7권3호
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• pp.61-70
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• 2002

난분해성 유기오염물로 오염된 토양 복원을 위한 전자빔 직접조사 공정의 적용가능성을 평가하기 위하여 PAHs 와 PCBs로 오염시킨 토양에 대한 전자빔 조사실험을 수행하였다 전자빔 흡수선량 600kGy에서 PAHs의 제거율은 약 97% 이었고 PCBs는 800kGy에서 약 70%가 제거되었다. PAHs는 PCBs에 비해 낮은 흡수선량에서도 높은 제거율을 나타내었다. 오염물의 분해는 가속된 전자와 물의 반응으로 생성된 반응성 높은 중간생성물에 의한 산화/환원 반응보다는 고에너지 전자와 대상오염물의 직접적인 반응에 기인한다. 전자빔 조사에 의해 난분해성 오염물질로 오염된 토양을 효과적으로 제거할 수 있으나 이를 위해 높은 에너지를 요구하므로 비경제적인 공법이 될 수 있다. 따라서, 전자빔 직접조사 공정보다는 기존 토양복원 공법의 후처리 공정으로 개발하는 것이 경제적이고 실용화 가능할 것으로 판단된다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제22권6호
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• pp.48-56
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• 2017

Although various methods have been investigated for treatment of crude oil contaminated soil, more researches are still required to preserve soil environment. This study investigated the potential utility of subcritical water in remediation of crude oil contaminated soil under various experimental conditions including temperature ($150-300^{\circ}C$), flow rate (1.0-2.0 mL/min) and extraction time (60-120 min). The removal rate of crude oil gradually increased with increasing temperature and time. After treatment at $200^{\circ}C$ and $300^{\circ}C$ for 60 min, the remaining concentration of crude oil met the Kuwait standard clean-up level (10,000 mg/kg) and the Korean standard level (2,000 mg/kg), respectively. The removal efficiency of crude oil increased from 77.8% to 88.4% with increasing extraction time from 60 to 120 min at $250^{\circ}C$. A decreasing rate of oil removal was observed as flow rate increased, possibly due to channeling flow occurred within the soil body at higher flow rate condition. Overall, the results revealed that subcritical water extraction process could be feasible for remediation of crude oil contaminated soil, and the relative effect of parameters on the oil removal was in the order of temperature > time > flow rate.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.297-300
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• 2004

The various microbial tests were performed to determine bioremediation agent capacity for eight strains isolated from the oil contaminated regions. Two tests for isolated strains were conducted such as cell hydrophobicity and emulsifying activity. The biodegradation of SHM (saturated hydrocarbon mixture) and AHM (aromatic hydrocarbon mixture) with the strains also was carried out. The strains having higher cell hydrophobicity and emulsifying activity degraded petroleum oil effectively. The degradation capacity for SHM was represented more than 90% in YS-7 and WLH-1 of isolated strains, and KH3-2 were capable of degrading AHM. Especially, WLH-1 as yeast was shown more than two or three times in the degradation capacity of automobile engine lubricants and the biomonitoring results of contaminated soil for residual oil degrading test showed that the hydrocarbon biodegradation was increased in the second treatment by this strain.

• 한국지하수토양환경학회지:지하수토양환경
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• 제15권2호
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• pp.1-9
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• 2010

Estimations of porosity and bulk density, particle size analysis of soli samples, tracer test and slug test were performed in a petroleum contaminated area of Kangwon for understanding characteristics of the aquifer. Porosities of the samples were estimated 0.158~0.257, and bulk densities were estimated as $1.73\sim2.10\;g/cm^3$. Majority proportion of the soil samples was 0.5~1.0 mm size. In the soil texture triangle, all samples were distributed at sand area. Uniformity coefficients were estimated as 7.71~10.39, and thus all samples were poorly-sorted. In the tracer test, Darcy velocity was estimated to $4.8\times10^{-6}$ cm/day, effective porosity was 0.175, and longitudinal dispersivity was 0.1 m. According to the slug test, hydraulic conductivities of the test wells were estimated as $2.243\times10^{-2}\sim1.634\times10^{-2}$ cm/sec. These hydrogeologic parameters can be used for efficient remediation design of the petroleum contaminated area.