• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.410-416
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• 2005

생물학적 통풍법은 유류오염 지역에 자주 적용되는 정화공법이다. 이 과정은 지중에 산소를 충분히 공급함으로서 토착 미생물에 의한 오염성분의 분해를 가능하게 한다. 따라서 이 공법의 적용시 공정진행에 따른 공법의 효율성 분석과 장기적인 정화효율 예측을 위한 지중 가스성분의 모니터링 시스템 도입이 매우 중요하다. 그러나 우리나라에서는 아직 그 적용사례가 보고된 바 없다. 따라서 본 연구에서는 현장에서 토양가스 성분의 변화를 모니터링할 수 있는 시스템을 개발하여 적용한 사례를 시스템의 구성과 측정방법, 관측결과를 중심으로 소개하였다. 현장적용 결과는 토양가스 모니터링 시스템은 운용 시작 후 6개월동안 센서나 측정장비에서 문제가 발생되지 않았으며, 공정관리를 위한 공법효율성 분석에 필요한 자료를 지속적으로 제공하고 있다.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.466-466
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• 2023

전세계적으로 2050년까지 탄소 배출량을 0으로 만들기 위한 탄소중립을 선언하였고, 우리나라에서는 온실가스 감축 목표 달성을 위해 논물관리기술 확산, 가축분뇨 자원순환 등 농업 분야 탄소 저감 계획을 수립하였다. 특히, 논물관리기술을 통한 탄소 저감 목표를 달성하기 위해서는 지역별 적합한 논물관리기술 모델이 개발되어야 한다. 이에 본 연구에서는 강원도 지역에 적합한 논물관리기술 모델 개발을 위해 강원도 원주시 일대 6개의 시험포를 조성하여 메탄 발생량을 모니터링 하였다. 각 시험포는 상시담수(S1), 4주 중간 물떼기+얕게 걸러 대기(S2), 4주 중간 물떼기+얕게 대기(S3), 3주 중간 물떼기+얕게 걸러 대기(S4), 2주 중간 물떼기+얕게 걸러 대기(S5), 2주 중간 물떼기+얕게 대기(S6)로 논물관리기간을 다르게 설정하였다. 그리고 각 시험포에는 메탄 발생량 모니터링을 위해 각각 3개의 챔버와 논물관리를 위한 자동물꼬조절장치를 설치하였다. 메탄발생량 모니터링은 2022년 5월부터 2022년 9월까지 총 5개월 동안 25회 진행하였다. 메탄 발생량 모니터링 결과 S1은 423.1 kg/ha, S2는 348.4 kg/ha, S3은 396.4 kg/ha, S4는 164.7 kg/ha, S5는 347.9 kg/ha, S6은 234.1 kg/ha 의 메탄이 배출된 것으로 분석되었다. 분석결과와 같이 S1에서 메탄 발생량이 가장 많았으며, S4에서 가장 적게 발생한 것으로 분석되었다. 논에서 발생되는 메탄에 영향을 주는 인자는 토양 유기물, 토양 산도 등이 중요한 요인으로 알려져 있으며, 이앙 전과 수확 후 토양분석을 진행한 결과 시험포별 인자별 변화량 차이가 나타났다. 따라서 장기적인 모니터링을 통해 논물관리기술에 따른 토양유기물 및 토양 산도 변화에 대한 보완이 필요할 것으로 판단되며, 지속적인 메탄 발생량 모니터링을 통해 강원도 지역에 적합한 논물관리기술을 적용해야 할 것으로 보여진다.

• Economic and Environmental Geology
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• v.55 no.4
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• pp.407-419
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• 2022

Soil(vadose zone) gas compositions were measured for about 3 days to suggest a method for monitoring and interpreting soil gas data collected around wells from which methane(CH₄) is outflowing. The vadose zone gas samples were collected within 1 m around two test wells(TB2 and TB3) at Pohang and analyzed for CO₂, CH₄, N₂ and O₂ concentrations in situ. CO₂ flux was measured beside TB2. In addition, gas samples from well head in TB2 and atmospheric air samples were collected for comparison. Carbon isotopes of CO₂(δ¹³C_CO2) of samples collected on the last day of the study period were analyzed in the laboratory. The two test wells (TB2 and 3) were 12.7 m apart and only TB3 was cemented to the surface. According to the bio-geochemical process-based interpretation, the relationships between CO₂ and O₂, N₂, and N₂/O₂ of vadose zone gas were plotted between the lines of CH₄ oxidation and CO₂ dissolution. In addition, the CH₄ concentrations of gas samples from the wellhead of the uncemented well (TB2) were 5.2 times higher than the atmospheric CH₄ concentration. High CO₂ concentrations (average 1.148%) of vadose zone gas around TB2 seemed to be attributed to the oxidation of CH₄. On the other hand, the vadose zone CO₂ around the cemented well(TB3) showed a relatively low concentration(0.136%). This difference indicates that the vadose zone gas(including CO₂) around the CH₄ outflowing well were strongly affected by well completion(cementing). This study result can be used to establish strategies for environmental monitoring of soil around natural gas sites, and can be used to monitor leakage around injection and observation wells for CO₂ geological storage. In addition, the method of this study is useful for soil monitoring in natural gas storage and oil-contaminated sites.

• The Journal of the Petrological Society of Korea
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• v.18 no.4
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• pp.279-291
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• 2009

Radon is a natural radionuclide originated from radioactive decay of radium in rocks and soil. It is colorless, odorless and tasteless elements that mainly distributed as gaseous phase in soil pore space. The present study analyzed the characteristics of long-term radon variation in granitic residual soil at Mt. Guemjeong in Guemjeong-gu, Busan and determined the effects of atmospheric temperature, rainfall and soil temperature and moisture. Periodic measurements of radon concentrations in soil gas were conducted by applying two types of in-situ monitoring methods (chamber system and tubing system). Radon concentration in soil gas was highest in summer and lowest in winter. The variations in soil temperature and atmospheric temperature were most effective factors in the long-term radon variations and showed positive co-relations. The air circulation between soil air and atmosphere by the temperature difference between soil and atmosphere was analyzed a major cause of the variation. However, other factors such as atmospheric pressure, rainfall and soil moisture were analyzed relatively less effective.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.05a
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• pp.125-128
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• 2000

Recently, development of advanced soil monitoring technology has became essential for effective site remediation. Soil gas evaluation is simple and powerful technology which can reduce the environmental impact during the survey of VOC contaminated area. In this research, the feasibility test of SnO$_2$ceramic gas sensor is conducted to improve soil gas measurement technology. As a result, it is successfully proved that this gas sensor has an possibility for soil gas monitoring.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.4
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• pp.90-96
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• 2003

This study was performed to evaluate effect of extraction mode on SVE efficiency for fuel-contaminated soil. A gas station was selected for this study. As a result of pressure test in well head, soil texture of contaminated site under the gas station was very different from site to site. SVE system was operated in intermittent mode (1hr extraction / 3hr rest) or continuous mode. Capacity of air blower was $1m^3/min$. Extration mode test was conducted in two severe contaminated sites. In both two sites, cumulative TPHgas mass of intermittent extraction mode was higher than that of continuous mode. Considering long term operation of SVE in a field, in general, it was thought that intermittent extraction mode was effective in view of vaporized TPHgas mass and electrical cost.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.232-232
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• 2023

고속도로 및 편의시설 건설로 불투수층의 면적이 증가하여 강우 시 고속도로 및 편의시설에서 발생하는 오염원에 의한 하천의 수질 영향도 커지고 있다. 특히 휴게소에서는 자동차의 급가속, 급감속으로 더욱 많은 분진과 오염물질이 발생할 수 있으며 타이어 마모 입자, 자동차 배기가스, 중금속 및 오일류 등이 휴게소나 도로 지표에 집적되어 있다. 이렇게 발생한 오염물질은 우기에 강우와 함께 불투수면을 침투하지 못하고 배수로를 통해 유출되어 인근 하천의 수생태 및 토양의 주요 오염원으로 작용하고 있다. 이에 따라 고속도로 및 인근 휴게소의 비점오염 저감대책이 필요하며 효율적인 비점오염원 저감을 위해 장기적인 모니터링, 지속적인 자료 수집 및 분석이 필요하다. 본 연구에서는 강원지역 고속도로 및 인근 휴게소에서 강우 시 강우유출수 모니터링을 통해 강우유출수 유량가중평균농도 (Event Mean Concentration) 산정하고 강우유출수 수문곡선 (hydrograph)을 작성하였다. 또한 강우사상에 따른 분석항목별 초기세척효과(First Flush Effects)와 오염부하량을 산정하였다. 추가적으로 차량 기인 입자를 확인하기 위해 μ-FT-IR 현미경 분석 실험을 하였다. 모니터링 장소는 휴게소 및 고속도로 일원이며, 모니터링은 선행무강우일수 2일 이상, 강우량 10mm 이상일 때 실시하였으며 2022년 6월부터 10월까지 총 4회 실시하였다. 모니터링 결과 타이어 및 브레이크 패드 마모와 관련된 중금속인 Zn, Cu, Pb 등의 중금속이 높게 분석되었으며 이러한 중금속의 오염부하량 역시 높게 산정되었다. 강우유출수 수문곡선에서 강우 초기 오염물질의 세척효과가 나타났다. MFFn 산정 결과 강우 30% 구간에서 초기세척효과를 보였다. μ-FT-IR 현미경 분석 결과 PE (Polyethylene)가 가장 많이 검출되었고 PP (Polypropylene), PS (Polystyrene) 순으로 검출되었다. 이러한 강우유출수 모니터링 데이터는 향후 고속도로 휴게소 및 고속도로 주변 오염저감 시설 설치 및 사회적 동참을 위한 타당한 근거 확보를 위한 기초자료로서 제공될 수 있을 것이다.

• Geophysics and Geophysical Exploration
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• v.8 no.2
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• pp.137-144
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• 2005

In this study, we offered the results of geophysical and geochemical survey on the municipal waste disposal area to delineate the size and extent of leachate contamination. Preliminary to intensive geochemical investigation, we performed two geophysical methods to characterize the survey area. Electromagnetic (EM) and magnetic method were used far site investigation. From the EM method, we can get the information of soil conductivity directly related to the leachate of the contaminations and from magnetic anomalies we can find the boundary of landfill which is not identified on the surface due to soil capping. The results of geophysical survey were well matched to those of geochemical method carried out inside and near the landfill. Electric conductivity (EC) of the groundwater sampled from low resistivity anomaly region of EM result was higher than background value and the border estimated from the magnetic survey showed good agreement with that estimated from the soil gas detection survey.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.250-252
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• 2002

The goals of environmental monitoring are to locate and quantify the significant contamination, estimate the fate and transport, estimate the potential exposure and risks to humans and the environment, and track the performance of various remedial technologies. In this study, ceramic gas sensor system is proposed to enhance the effectiveness of soil vapor extraction (SVE) process by monitoring the effluent gas. SVE is a technique that is widely used to remediate unsaturated soils contaminated with volatile organic contaminants. The sensor response for benzene, toluene, and xylene, the representative effluent gas compositions of SVE process, was evaluated using the proposed sensor system. As a result, it was verified that the response of sensor was increased or decreased very sensitively according to the change of the effluent gas concentration. Besides, the sensor could detect the difference over a wide range of concentration and it was more sensitive in order of xylene, toluene, and benzene. It is expected that this VOC analysis method results in field monitoring costs saying and appropriate immediate action for process control. More detailed experiments are being conducted in our research group.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.2
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• pp.79-91
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• 2020

Accurate assessment of greenhouse gas emissions is a cornerstone of every climate change response study, and reliable assessment of greenhouse gas emission data is being used as a practical basis for the entire climate change prediction and modeling studies. Essential, fundamental technologies for estimating greenhouse gas emissions include an on-site monitoring technology, an evaluation methodology of uncertainty in emission factors, and a verification technology for reductions. The closed chamber method is being commonly used to measure gas fluxes between soil-vegetation and atmosphere. This method has the advantages of being simple, easily available and economical. This study presented the technical bases of the closed chamber method for measuring methane fluxes from a rice paddy. The methane fluxes from rice paddies occupy the largest portion of a single source of greenhouse gas in the agricultural field. We reviewed the international and the domestic studies on automated chamber monitoring systems that have been developed from manually operated chambers. Based on this review, we discussed scientific concerns on chamber methods with a particular focus on quality control for improving measurement reliability of field data.