• Journal of the Korean GEO-environmental Society
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• v.12 no.6
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• pp.17-23
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• 2011

In this study, a series of experiments were carried out to remove total petroleum hydrocarbon(TPH) and toluene by soil flushing. In batch experiments, Triton X-100 and SWA 1503 showed TPH removal efficiency of 79.0% and 69.0%, respectively. Although the TPH removal efficiency increased as the surfactant was increased in the concentration range 1-11mmol/L, the optimum concentration was 1mmol/L, considering the ratio of the removal efficiency to the amount of surfactant injected. In column experiment, the optimal velocity was 0.3mL/min. The physical aquifer model(PAM) result revealed that the soil flushing removed as much as 5.5% of the toluene under 3 pore volume(PV) conditions. To improve the soil flushing efficiency, it is necessary to find optimal condition through recirculation or reuse of surfactant.

• Journal of Bio-Environment Control
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• v.8 no.4
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• pp.232-241
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• 1999

The automatic irrigation system using the stem diameter monitoring and the transpiration model for the determination, respectively, of irrigation timing and amount was designed and evaluated for its applicability in pot and field culture of greenhouse tomato. In the pot culture condition, the yield and quality of greenhouse tomato were improved when irrigation was practiced based on the stem diameter monitoring and the transpiration model as compared to the irrigation practice based on soil moisture monitoring. However, the effects were not significant in the field culture condition.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3B
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• pp.211-220
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• 2011

In this study a conceptual soil water model is proposed to simulate water balance at catchment scale. The model is based on the sequential separation of daily precipitation into surface runoff, wetting, vaporization, and percolation. The proposed model is calibrated by using three observation sets: empirically estimated annual vaporization, monthly wetting estimated by NRCS-CN method, and both of them. The model performance is evaluated to understand which hydrologic components for calibrating the model are needed. It is shown that both of annual vaporization and monthly wetting are indispensable hydrologic components to simulate reasonably precipitation partitioning.

• Journal of Soil and Groundwater Environment
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• v.16 no.1
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• pp.62-70
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• 2011

This study was conducted to evaluate the performance of soil-cement walls (SCWs) to control leachate from a leaking landfill site. Tracer tests revealed that the SCW was effective to control groundwater seepage. Approximately two-months of curing period appeared to be sufficient to ensure thorough containment of landfill leachate, although a three-week period was not enough. The water quality of the monitoring wells after construction of the SCWs met the groundwater quality standard of the korean Waste Management Act, except for bacteria and coliform groups. Also an analysis of a spring water around the landfill showed that the concentrations of ammonia, inorganic nitrogen and soluble manganese which had been common contaminants in the spring water decreased dramatically after constructing the walls. Therefore, the results suggested that a SCW can be an attractive method to control leachate from a leaking landfill site.

• Current Research on Agriculture and Life Sciences
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• v.1
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• pp.95-100
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• 1983

A soil hardness meter with strain gages was developed in order to measure the hardness of the soil. Soil hardness tests were conducted at the laboratory based on this measuring system. Also, these results were compard with that from the cone penetrometer which is widely used for this purpose. The following conclusions were drawn from the results. 1. Since the correlation coefficient of calibration curve obtained from the soil hardness meter with strain gages was 0.99876 and that of calibration curve obtained from the cone penetrometer with dial gage was 0.97150, the soil hardness meter with strain gages was more recomendable than that with dial gage for this purpose. 2. Standard deviations of soil hardness for sands and soil of paddy field when the soil hardness meter with strain gages was used were 6.794 and 8.271, respectively and that of soil hardness for sands and soil of paddy field when the cone penetrometer with dial gage was used were 7.490 and 9.169, respectively. Thus, the soil hardness meter with strain gages seemed to have lower measuring error than with dial gage.

• Journal of Korea Water Resources Association
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• v.53 no.3
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• pp.181-191
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• 2020

In order to produce accurate initial condition of soil moisture for global Numerical Weather Prediction (NWP), spin-up experiment is carried out using Noah Land Surface Model (LSM). The model is run repeatedly through 10 years, under the atmospheric forcing condition of 2008-2017 until climatological land surface state is achieved. Spin-up time for the equilibrium condition of soil moisture exhibited large variability across Koppen-Geiger climate classification zone and soil layer. Top soil layer took the longgest time to equilibrate in polar region. From the second layer to the fourth layer, arid region equilibrated slower (7 years) than other regions. This result means that LSM reached to equilibrium condition within 10 year loop. Also, spin-up time indicated inverse correlation with near surface temperature and precipitation amount. Initialized from the equilibrium state, LSM was spun up to obtain land surface state in 2018. After 6 months from restarted run, LSM simulates soil moisture, skin temperature and evaportranspiration being similar land surface state in 2018. Based on the results, proposed LSM spin-up system could be used to produce proper initial soil moisture condition despite updates of physics or ancillaries for LSM coupled with NWP.

• Journal of Environmental Impact Assessment
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• v.30 no.4
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• pp.247-257
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• 2021

In this work, Iron Nano-Particles Impregnated BioChar/bead (INPBC/bead) soil amendment was developed to increase biochar's reactivity to As in soil and preventing possible wind loss. Prior to preparation of INPBC/bead, INPBC was produced utilizing lignocellulosic biomass and Fe(III) solution in a hydrothermal method, followed by a calcination process. Then, the bead type amendment, INPBC/bead was produced by cross-linking reaction of alginate with INPBC. FT-IR, XRD, BET, and SEM-EDS analyses were utilized to characterize the as-synthesised materials. The particle size range of INPBC/bead was 1-4 mm, and different oxygen-containing functional groups and Fe3O4 crystalline phase were produced on the surface of INPBC/bead, according to the characterization results. The soil cultivation test was carried out in order to assess the stabilization performance of INPBC/bead utilizing As and Pb-contaminated soil obtained from an abandoned mining location in South Korea. After 4 weeks of culture, TCLP and SPLP extraction tests were performed to assess the stabilization efficacy of the amendment. The TCLP and SPLP findings revealed that raising the application ratio improved stabilizing efficiency. The As stabilization efficiency was determined to be 81.56 % based on SPLP test findings for a 5% in (w/w) INPBC/bead treatment, and the content of Pb in extracts was reduced to the limit of detection. According to the findings of this study, INPBC/bead that can maintain pH of origin soil and minimize wind loss might be a potential amendment for soil polluted with As and heavy metals.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.09a
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• pp.41-46
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• 2001

요오드나 세순 같은 핵종들은 고용해도 핵 종들로서 사용 후 핵연료 내 피복관 이나 연료 결정 경계면에 위치하고 있다가 고준위 방사성폐기물 처분 후 지하수가 용기를 부식시키고 용기 내부로 침투하면 고용해도를 가지고 유출된 후 공학적, 천연 방벽을 통해 최종적으로 유출되게 된다. 본 연구에서는 한국원자력연구소에서 개발한 MASCOT-K글 이용하여 고용해도 핵 종들이 조화 유출과 고용해도 유출할 경우 유출 량을 평가 분석해 보았다. 평가 결과 요오드와 같은 고용해도 핵 종인 경우 전체 핵 종 재고량의 최대 10%만이 고용해도 유출을 하지만 그 영향은 조차 유출에 비해 훨씬 중요한 것으로 판명되었다. 이러한 결과를 바탕으로 현재 국내 고 준위 처분 환경에서 보수적인 시나리오로 주목받고 있는 우물 굴착 시나리오를 대상으로 우물까지의 거리 등 입력 자료의 불확실성을 평가해 보았다. 36,000 톤의 사용 후 핵연료를 처분 대상으로 했을 때 성능 평가 결과는 현재 처분 개념이 안전함을 입증한다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1997.11a
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• pp.35-50
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• 1997

쓰레기 매립장의 오수 침출 방지를 목적으로 그간 차수층이 시공되었으나 기존의 차수재는 그 성능상 많은 문제점을 내포하고 있었다. 이게 본 고에서는 '자가 형성' 및 '자가 치유'기능을 가진 SS/SH 차수층에 관하여 실내 시험 및 수도권 매립지(3공구)를 대상으로 현장 시험시공을 실시한 결과에 관해서 기술하였다. 두 시험을 통하여 SS/SH 차수층은 쓰레기 매립장 차수재로써 필요한 기준강도를 충족시키는가 하면 투수계수도 기준치를 만족시키는 낮은 수치를 나타내는 등 우수한 기능성을 충분하게 입증하였다. 무엇보다, 쓰레기 매립장에서 일반적으로 발생하는 차수층 손상에 대한 '탁월한 치유기능'을 가지고 있음으로 차수층 보수비가 전혀 필요없다는 점에서 대단히 경제적이라고 판단되었기에, 기능성과 경제성을 확보한 이 SS/SH 공법을 본공사에 적용할 수 있게 된 것이다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.13-16
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• 2005

Laboratory and field experiments were conducted to study the effectiveness of five adsorbents for the removal of arsenic. The adsorbents included activated alumina (AA), iron coated AA (ICAA), and granular ferric hydroxide (GFH), granular ferric oxide (GFO), and granular titanium dioxide (GTD). Laboratory experiments were conducted to investigate arsenic removal using challenge water prepared in accordance with NSF International Standards 53 (ANSl/NSF 53-2001). Field experiments were conducted using arsenic-contaminated groundwater In laboratory experiment, the treatment capacity decreased in the following order GTD > GFO > GFH. In contrast, the treatment capacity decreased in the following order GFO > GTD > GFH > ICAA > Ah in field experiments.