• Journal of Korean Society of Environmental Engineers
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• v.36 no.9
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• pp.659-666
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• 2014

The purpose of this study was to suggest a standard design procedure of landfarming for clean-up of oil-contaminated soils. The standard design procedure consisted of four main phases; soil characterization, determination of contaminated soil volume, determination of nutrient and microbial doses, and estimation of the total remedial period. This study selected standard design parameter values or ranges among various forms used in environmental engineer communities. Those were determination procedures for the contaminated soil volume, the initial contamination concentration and nutrient doses. The suggested standard design procedure were applied for a landfarm design for remediation of a real oil-contaminated site. Soil texture of the site was classified as sandy clay loam and sandy loam. Total nitrogen and total phosphorus were estimated to be 57.01 mg/kg and 83.40 mg/kg, respectively. Also the viable bacterial numbers was assessed to be $1.78{\times}10^4CFU/g$ dry soil. The amount of TPH contaminated soil was estimated to be $4,092m^3$. With the application of remedial factors, it was estimated that the contaminated soil could be treated through 9 batches with a duration of 315 days for a landfarming unit of $15m{\times}40m{\times}1m$. The amount of liquid microorganisms and fertilizers were recommended to be 4,025L and 4,641kg, respectively.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1998.06a
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• pp.22-26
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• 1998

토양오염 정화방법의 하나인 토양증기추출법(soil vapor extraction, SVE)은 오염된 토양에 진공 또는 가압의 공기를 공급하여 연속적인 공기 흐름을 유도함으로써 토양의 기공에 잔류하는 유해화합물의 증발을 촉진하여 오염물질을 제거하는 공정이다. 본 연구에서는 토양증기추출법의 효율에 영향을 주는 인자들 가운데에서 토양의 수분함량과 오염물질의 종류가 오염물질의 제거효율에 미치는 영향에 대한 실험과 계산을 수행하였다. 인공토양으로 glass bead, sand, molecular sieve가 사용되었으며. 오염물질로는 톨루엔. 메틸에틸케톤, 트리클로로에틸렌이 사용되었다. 각 실험에 대하여 프로인들리히 등온식과 기공확산모델 등을 고려하여 계산을 수행한 결과, 수분이 없는 경우에는 탈착식에 의해, 수분이 있는 경우에는 interparticle에서의 확산 현상에 의해 오염물질의 제거속도가 지배됨을 알 수 있었다. 이러한 연구결과는 정화대상지역에 SVE를 이용한 적절한 정화방법을 설계하는데 기초자료로 이용할 수 있을 것이다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.5
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• pp.839-846
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• 2016

Since oil leakage is one of the most common nonpoint pollution sources that contaminate soil in Korea, the capacity of soil microbial community for degrading petroleum hydrocarbons should be considered to assess the functional value of soil resource. However, conventional methods (e.g., microcosm experiments) to assess the remediation capacity of soil microbial community are costly and time-consuming to cover large area. The present study suggests a new approach to assess the toluene remediation capacity of soil microbial community using a microbial diversity index, which is a simpler detection method than measuring degradation rate. The results showed that Shannon index of microbial community were correlated with specific degradation rate ($V_{max}$), a degradation factor. Subsequently, a correlation equation was generated and applied to Michaelis-Menten kinetics. These results will be useful to conveniently assess the remediation capacity of soil microbial community and can be widely applied to diverse engineering fields including environment-friendly construction engineering fields.

• Journal of Korea Soil Environment Society
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• v.1 no.2
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• pp.91-101
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• 1996

In recent years, phytoremediation, the use of plants to detoxify hydrocarbons, has been a promising new area of research, particularly in situ cleanup of large volumes of slightly contaminated soils. There is increasing need for a mathematical model that can be used as a predictive tool prior to actual field implementation of such a relatively new technique. Although a number of models exist for solute-plant interaction in the vegetated zone of soil, most of them have focused on ionic nutrients and some metals. In this study, we developed a mathematical model for simulation of bioremediation of hydrocarbons in soil, associated with plant root systems. The proposed model includes root interactions with soil-water and hydrocarbons in time and space, as well as advective and dispersive transport in unsaturated soil. The developed model considers gas phase diffusion and liquid-gas mass exchanges. For simulation of temporal and spatial changes in root behavior on soil-water and with hydrocarbons, time-specific distribution of root quantity through soil was incorporated into the simulation model. Hydrocarbon absorption and subsequent uptake into roots with water were simulated with empirical equations. In addition, microbial activity in the rhizosphere, a zone of unique interaction between roots and soil microorganisms, was modeled using a biofilm theory. This mathematical model for understanding and predicting fate and transport of compound in plant-aided remediation will assist effective application of plant-aided remediation to field contamination.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1999.04a
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• pp.33-34
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• 1999

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1239-1244
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• 2010

중금속 및 유류 오염토양 정화를 위해 효율적인 토양세척법과 공정 선정을 목적으로 최적의 오염정화 설계인자를 제시하기 위한 실험적 연구를 수행하였다. 실험분석 항목은 구리, 납, 아연을 포함하는 중금속항목과 총석유계탄화수소(TPH)인 유류항목에 대해 흡광광도법(absorptiometric analysis), 기체 크로마토그래피(gas chromatography)법을 이용하여 단계별로 분석하였다. 실험방법은 최적 세척용매 결정시험, 최적 세척시간 도출시험, 최적 진탕비(S/W ratio) 결정시험 등을 통해 얻어진 결과를 토대로 계면활성제 첨가량별 중금속 용출영향 분석시험 순으로 실시하였다. 실험결과 세척용매인 염산 0.1mole, 체류시간 1시간, 진탕비 1:3 조건에서 오염물질의 저감효과가 우수하게 나타났으며, 이들 조건을 적용하였을 때 1%의 계면활성제를 세척용매에 첨가하였을 경우 추가적인 오염물질의 농도 저감효과가 있는 것으로 분석되었다.

• Journal of the Korean GEO-environmental Society
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• v.17 no.10
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• pp.63-71
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• 2016

Soil filling or replacement are routinely applied for soil restoration of domestic asbestos waste contaminated areas. However, since these soil recovery methods could not fundamentally solve the asbestos contamination, number of research on new alternative technologies have been carried. In this study, comprehensive laboratory test results utilizing wind power apparatus are used to design wind power purification device that can be applied in practice. Preliminary tests were carried out with wollastonite or actual asbestos waste contamination soils to study purification efficiency. Asbestos content measured immediately after in-situ test on asbestos-contaminated soil satisfying for purification standard showing less than 0.25% asbestos content from all tests, hence, analyzed to ensure over 90% of clean soil recovery rate and considered to be excellent applicability of future asbestos-contaminated soil purification.

• Journal of Korea Soil Environment Society
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• v.3 no.2
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• pp.101-114
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• 1998

Soil vapor extraction (SVE) is known to be an effective process to remove the contaminants from the soils by enhancing the vaporization of organic compounds using forced vapor flows or applying vacuum through soils. Experiments are carried out to investigate the effects of the organic contaminants, types of soils, and water contents on the removal efficiency with operating time. In the study, simulated soils include the glass bead which has no micropore, sand and molecular sieve which has a large volume of micropores. As model organic pollutants, toluene, methyl ethyl ketone, and trichloroethylene are selected. Desorption experiments are conducted by flowing nitrogen gas. Under the experimental conditions, it is found that there are linear relationships between logarithm of removal efficiency and logarithm of number of pore volumes. The number of pore volumes are defined as the total amount of air flow through the soil column divided by the pore volume of soil column. For three organic compounds studied, the removal rate is slow for no water content, while the number of pore volumes for removal of organic compounds are notably reduced for water contents up to 37%. For the removal of dense organic compound, such as trichloroethylene, a large number of pore volumes are needed. Also, the effects of the characteristics of simulated soils on the removal efficiency of organic compounds are studied. After the characterization of soil surface, porosity of soil columns and types of contaminants, the results could provide a basis for the design of SVE process.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1998.11a
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• pp.146-150
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• 1998

현재 세계적인 토양환경복원의 추세는 단기간의 높은 처리효율을 기대하는 장치위주의 복원기술적용에서 좀 더 처리시간은 걸리나 저비용의 효율적인 처리기술선택으로 옮겨가고 있다. 이는 지금까지 무리한 투자에서 발생한 부작용을 최소화하기 위해서 취해지고 있는 변화로 식물을 이용한 환경복원기술(phytoremediation)은 이러한 변화에 가장 잘 부응하는 발전 가능성이 매우 높은 미래 복원기술 가운데 하나이다. 이에 본 연구에서는 phytoremediation을 이용하여 디젤로 오염된 토양을 복원하고자 하였다. 먼저 대상오염물에 대한 정화능을 나타내는 식물을 선별하기 위해 알팔파, 옥수수, 피, 물피의 오염농도별 생장 률을 살핀 결과 알팔파가 오염농도에 따른 성장저해를 가장 덜 받는 것으로 나타났다. 이에 알팔파의 발아 test를 거친 후 실제상황을 모사하기 위한 column test를 실시하여 디젤의 제거효율을 살펴보았다. 1)외부로부터 pipe line을 따라 공기를 주입하여 산소를 보충한 처리구와 2)알팔파를 심은 처리구, 3)알팔파와 공기를 넣어준 처리구를 설계하여 디젤의 제거과정을 알아본 결과 제거효과가 가장 높은 처리구는 공기와 알팔파를 함께 넣어준 처리구였다. 이를 통해 유류로 오염된 토양에서 산소가 미생물활동에 커다란 제한요인이라는 것과 공정에 공기주입구를 장착함으로써 식물만으로 처리할 때 대두되는 시간적 제약의 문제를 다소 경감시킬 수 있음이 밝혀져 앞으로 이의 활용가능성이 주목된다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1998.11a
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• pp.52-56
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• 1998

최근 들어 국외에서는 오염된 지하수의 정화기술로써 0가 금속을 이용한 방법이 높은 잠재력을 가진 신기술로 알려져 있다. 본 연구에서는 0가 금속중 나노크기(1-100nm)를 가진 0가 철입자를 이용하여 수중의 NO$_3$￣를 탈질처리하는 실험을 행하였다. 본 실험에서 제조한 나노크기 0가 철입자는 상온상압의 환원적 조건에서 50, 100, 200, 400mg/$\ell$의 NO$_3$￣와 반응하여 반응시간 30분안에 95%이상 제거되는 높은 반응성을 보여주었다. 기존의 상업용 철입자(10-100$\mu\textrm{m}$)를 이용한 NO$_3$￣의 제거결과에서 보여주는 다량의 철사용, 낮은 적용 오염농도, 그리고 낮은 반응속도등의 문제점에 비하여 나노크기 철 입자는 높은 오염농도범위에서도 적은 철 주입량과 짧은 반응시간 내에 매우 높은 제거효율(10-100배)을 나타내었다. 이러한 결과로 수중의 NO$_3$￣의 고속 탈질반응속도에 영향을 주는 중요한 변수는 반응에 참여하는 철 입자의 비표면적임을 알 수 있었다. 본 연구에서 얻은 batch실험 결과를 바탕으로 NO$_3$￣로 오염된 지하수의 정화를 위한 현장 적용을 목표로 연속처리 공정의 설계를 위한 토대를 마련하고자 하였다.