• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.83-86
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• 2003

Soil Aquifer Treatment (SAT) is a technique in which secondary- or tertiary-treated wastewater is infiltrated through unsaturated soil and stored in the saturated zone. In SAT, contaminants are removed by physical and biochemical reactions taking place in soils. In this study, a numerical model was developed to predict changes in water quality during SAT operations. The contaminant species considered in the model were ammonium, nitrate, dissolved organic carbon, and dissolved oxygen. The model was calibrated against experimental data obtained from one dimensional soil column tests conducted for 84 days. The calibrated model will be used to find out optimum conditions for the pilot- and regional-scale SAT operations to be scheduled for the next phase of this project.

• 한국농림기상학회지
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• 제11권3호
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• pp.87-99
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• 2009

2006년 광릉 활엽수림지역에서 관측된 자료를 활용하여 수정된 토양-식생-대기 모델을 보정하고 연간 순생태 교환량의 계절변동성에 대한 모델의 모의 능력을 평가하고 탄소교환을 조절하는 주요 인자에 대하여 조사하였다. 수정된 토양-식생-대기 모델(mSPA model)을 1000 LST부터 1400 LST까지 관측된 낮 시간의 평균 순 생태 교환량(Net ecosystem exchange)을 모의하도록 보정한 후 총 일차 생산량(Gross primary productivity)을 계산하는데 사용하였고 생태 호흡량(Ecosystem respiration)은 관측지에서 개발된 경험식을 사용하여 추정하였다. 모델 결과는 여름철에 낮 시간의 평균 기공 전도도는 일사량과 매우 높은 상관성이 있음을 나타내었고 수증기 포차는 기공전도도의 변화에 큰 영향을 미치지는 않음을 보였다. 모델은 성장기간에 두 개의 극대값을 갖는 관측된 순 생태교환량의 계절 변동성을 모의하였다. 모델에서 계산된 연간 총 생산량과 생태호흡량, 그리고 순 생태 교환량은 각각 $964gC\;m^{-2}\;yr^{-1}$, $733gC\;m^{-2}\;yr^{-1}$ 그리고 $-231gCm\;^{-2}\;yr^{-1}$이었다. 관측값에 기반하여 산정된 연구결과와 비교할 때 모델 추정값이 약 $140gC\;m^{-2}\;yr^{-1}$ 더 많은 탄소 흡수를 보였다. 복잡한 지형에서 연간 생태 교환량 추정의 불확실성에 대하여 논의하였다.

• 한국환경복원기술학회지
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• 제12권2호
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• pp.1-9
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• 2009

Due to the increase of carbon dioxide in the atmosphere and global warming, the importance of forest ecosystems, as a place of carbon accumulation and emission, has received a great amount of recognition lately. This study was performed to help understand and provide the current status of carbon cycle in the pinus densiflora stand, Korea. The samples were collected from average 35-years-old Pinus densifiora rands in Gongju, Youngdong, Chungsan, Muju, Mupung, and Jangsu regions. Total thirty aboveground sample trees were cut, and ten roots were sampled, and soil samples were collected. Average carbon concentrations in foliage, branch, stem bark, stem wood, and root were 55.7%, 56.0%, 56.0%, 57.3%, and 56.5%, respectively. Carbon content was estimated by the model $Wt=aD^b$ where Wt is oven-dry weight in kg and D is DBH in cm. Total carbon content (aboveground and root) was 42.39tonC/ha in the Pinus densiflora stand. The proportion of each tree component to total carbon content was high in order of stemwood, root, branch, stem bark, and foliage. Total net primary production (aboveground and root) was estimated at 6.51tonC/ha/yr in Pinus densiflora stand. The proportion of each tree component to total net primary carbon content was high in order of sternwood, root, branch, foliage and stembark. Soil carbon contents in the study sites was 43.51tonC/ha at 0-50cm soil depth.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권6호
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• pp.47-57
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• 2022

A number of different methods have been used for modeling the sorption of volatile organic chlorinated compounds such as tetrachloroethylene/perchloroethylene (PCE). In this study, PCE was adsorbed in several natural sorbents, i.e., Pahokee peat, vermicompost, BionSoil^®, and natural soil, in the batch experiments. Several sorption models such as linear, Freundlich, solubility-normalized Freundlich model, and Polanyi-Manes model (PMM) were used to analyze sorption isotherms. The relationship between sorption model parameters, organic carbon content (f_oc), and elemental C/N ratio was studied. The organic carbon normalized partition coefficient values (log K_oc = 1.50-3.13) in four different sorbents were less than the logarithm of the octanol-water partition coefficient (log K_ow = 3.40) of PCE due to high organic carbon contents. The log K_oc decreased linearly with log f_oc and log C/N ratio, but increased linearly with log O/C, log H/C, and log (N+O)/C ratio. Both log K_F,oc or log K_F,oc decreased linearly with log f_oc (R² = 0.88-0.92) and log C/N ratio (R² = 0.57-0.76), but increased linearly with log (N+O)/C (R² = 0.93-0.95). The log q_max,oc decreased linearly as log f_oc and log C/N increased, whereas it increased with log O/C, log H/C and log (N+O)/C ratios. The log q_max,oc increased linearly with (N+O)/C indicating a strong dependence of q_max,oc on the polarity index. The results showed that PCE sorption behaviors were strongly correlated with the physicochemical properties of soil organic matter (SOM).

• 한국환경과학회지
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• 제5권4호
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• pp.429-440
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• 1996

A global carbon cycle model (GCCM), that incorporates interaction among the terrestrial biosphere, ocean, and atmosphere, was developed to study the carbon cycling aid global carbon budget, especially due to anthropogenic $CO_2$ emission. The model that is based on C, 13C and 14C mass balance, was calibrated with the observed $CO_2$ concentration, $\delta$13C and $\Delta$14C in the atmosphere, Δ14C in the soil, and $\Delta$14C in the ocean. Also, GCCM was constrained by the literature values of oceanic carbon uptake and CO, emissions from deforestation. Inputs (forcing functions in the model) were the C, 13C and 14C as $CO_2$ emissions from fossil fuel use, and 14C injection into the stratosphere by bomb-tests. The simulated annual carbon budget of 1980s due to anthropoRenic $CO_2$ shows that the global sources were 5.43 Gt-C/yr from fossil fuel use and 0.91 Gt-C/yr from deforestation, and the sinks were 3.29 Gt-C/yr in the atmosphere, 0.90 Gt-C/yr in the terrestrial biosphere and 2.15 Gt-C/yr in the ocean. The terrestrial biosphere is currently at zero net exchange with the atmosphere, but carbon is lost cia organic carbon runoff to the ocean. The model could be utilized for a variety of studies in $CO_2$ policy and management, climate modeling, $CO_2$ impacts, and crop models.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.159-159
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• 2022

Soil represents a substantial component within the global carbon cycle and small changes in the SOC stock may result in large changes of atmospheric CO₂ particularly over tens to hundreds of years. In this study, we aim to (i) evaluate the SOC stock in the topsoil 0 - 15 cm from soil physical and chemical characteristics and (ii) find the correlation of SOC and soil organic matter (SOM) for national-scale in South Korea. First of all, based on the characteristics of the soil to calculate the soil hydraulic properties, SOC stock is the SOC mass per unit area for a given depth. It depends on bulk density (BD-g/cm³), SOC content (%), the depth of topsoil (cm), and gravel content (%). Due to insufficient data on BD observation, we establish a correlation between BD and SOC content, sand content, clay content parameter. Next, we present linear and non-linear regression models of BD and the interrelationship between SOC and SOM using a linear regression model and determine the conversion factor for them, comparing with Van Bemmelen 1890's factor value for the country scale. The results obtained, helps managers come up with suitable solutions to conserve land resources.

• 대한환경공학회지
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• 제36권8호
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• pp.588-595
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• 2014

탄소나노물질은 대표적인 나노물질로써, 풀러렌, 탄소나노튜브, 그래핀 등을 포함한다. 탄소나노물질은 다양한 분야에서 널리 이용되고 있는데, 생산, 사용, 처리 등의 단계에서 환경에 노출될 수 있고, 일단 노출이 되면 다양한 계로 확산되어 여러 생태학적 수용체에 큰 위협이 될 수 있다. 탄소나노물질이 토양환경에 노출되었을 때, 물의 흐름을 따라 토양을 통과하여 지하수에 노출될 가능성 여부를 판단하기 위하여 연구들이 진행되고 있다. 토양이 탄소나노물질의 이동을 제한하는 역할을 잘하는 것으로 판단될 경우에는, 탄소나노물질의 지하수 노출 가능성이 상당히 낮아질 것이다. 본 논문에서는 최근까지 토양 매질체에서 탄소나노물질의 이동과 관련하여 수행된 연구들을 정리하였다. 또한, 이러한 연구들을 통해 알려진 탄소나노물질의 이동에 영향을 미치는 인자들을 제시하였다. 그리고, 탄소나노물질의 이동을 모사하는데 이용되는 DLVO이론, 콜로이드 여과이론 그리고 이동모델을 제시하였다. 최근, 국내에서도 탄소나노물질의 생산과 상업적, 환경적 이용이 급속히 증가하고 있다. 따라서, 국내에서 생산되고 유통되는 탄소나노물질의 토양환경에서 이동에 관한 연구들이 향후에도 다양한 토양 환경조건에서 수행되어야 할 것으로 보인다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권2호
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• pp.22-28
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• 2016

In order to evaluate landfill stabilization based on organic carbon, stoichiometric analysis and a biological methane potential (BMP) test based on modeling were performed at the 2^nd Sudokwon Landfill Site. Mass balance analysis through a BMP test proved to be more adaptable for evaluation, and it showed that 28.9% of landfill organic carbon was expected to remain by 2046, 30 years after landfill closure. The organic carbon ratio of total landfill waste for 2046 is forecasted as 2.9% in demolition waste and 5.1% in household waste, and, if one were to consider plastic as an organic waste, the ratios would increase to 15.9% and 28.3%, respectively. Therefore, it seems that organic matter biodegradation facilitating measures such as bioreactor landfill technology and preemptive recovery of combustible waste are necessary to shorten post closure management periods and to meet the landfill stabilization guidelines more safely.

• 한국환경과학회지
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• 제16권3호
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• pp.287-297
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• 2007

Increasing carbon dioxide emissions from fossil fuel use and land-use change has been perturbing the balanced global carbon cycle and changing the carbon distribution among the atmosphere, the terrestrial biosphere, the soil, and the ocean. SGCM(Simple Global Carbon Model) was used to simulate global carbon cycle for the IPCC emissions scenarios, which was six future carbon dioxide emissions from fossil fuel use and land-use change set by IPCC(Intergovernmental Panel on Climate Change). Atmospheric $CO_2$ concentrations for four scenarios were simulated to continuously increase to $600{\sim}1050ppm$ by the year 2100, while those for the other two scenarios to stabilize at $400{\sim}600ppm$. The characteristics of these two $CO_2$-stabilized scenarios are to suppress emissions below $12{\sim}13$ Gt C/yr by tile year 2050 and then to decrease emissions up to 5 Gt C/yr by the year 2100, which is lower than the current emissions of $6.3{\pm}0.4$ Gt C/yr. The amount of carbon in the atmosphere was simulated to continuously increase for four scenarios, while to increase by the year $2050{\sim}2070$ and then decrease by the year 2100 for the other two scenarios which were $CO_2$-stabilized scenarios. Even though the six emission scenarios showed different simulation results, overall patterns were such similar that the amount of carbon was in the terrestrial biosphere to decrease first several decades and then increase, while in the soil and the ocean to continuously increase. The ratio of carbon partitioning to tile atmosphere for the accumulated total emissions was higher for tile emission scenario having higher atmospheric $CO_2$, however that was decreasing as time elapsed. The terrestrial biosphere and the soil showed reverse pattern to the atmosphere.

• 한국산림과학회지
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• 제102권1호
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• pp.82-89
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• 2013

벌채 수확은 토양 내 탄소 동태를 변화시킬 수 있는 중요한 교란 중 하나이다. 그러나 수확에 따른 토양탄소 변화를 현지에서 장기간 연구하는 데에는 여러 가지 제한 요건이 있기 때문에 수학적 모델을 이용하여 장기적인 토양탄소 변화 경향을 효율적으로 추정할 수 있다. 본 연구에서는 최근 개발된 한국형 산림토양탄소 모델(KFSC 모델)을 이용하여 국내 중부지방 소나무(Pinus densiflora S. et Z.) 임분을 대상으로 수확의 주기, 강도, 수확 후 잔재물 처리방법에 따른 산림토양탄소 동태의 장기 변화를 모의하였다. 모의 시나리오는 3개의 수확 주기(50년, 80년, 100년), 2개의 수확 강도(재적 대비 30%의 부분수확 및 100%의 개벌수확), 2개의 수확 후 잔재물 처리방법(지상부 잔재물의 전량 수거 및 전량 방치) 등을 조합하여 총 12개로 이루어졌으며, 연간 토양탄소 저장량의 변화를 400년 간 모의하였다. 모의 결과, 400년 후 30 cm 깊이까지의 토양탄소 저장량은 시나리오별로 50.3-55.8 Mg C $ha^{-1}$(현재 토양탄소 저장량 대비: 98.1-108.9%)의 범위를 나타냈다. 수확 후 잔재물을 전량 방치할 경우 잔재물을 전량 수거할 때보다 토양탄소 저장량이 2.5-11.0% 증가하는 것으로 모의되었으나, 수확 주기 및 강도에 따른 토양탄소 저장량 변화에서는 일정한 경향이 나타나지 않았다. 토양탄소 저장량의 변화 경향은 고사유기물의 변화 경향과 일치하였으며, 고사유기물의 변화 경향은 수확 시 발생하는 고사유기물의 양과 수확 후 임분 생장 형태에 의해 달라지는 것으로 나타났다.