• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1999.10a
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• pp.28-31
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• 1999

The purpose of this study is to see the effect of microbial population and dynamics of the indigeonous microorganisms on hydrocarbon contaminated areas. The microbial structures and activities to determine the microbial capabilities of the contaminated sites are very important for the remedial action technology selection. Throughout microbial studies on different conditions by ETS(Electron Transport System) and microbial activity analysis, it was found that aeration and water contents are the most important factors in this site remediation. According to test results, Burkholderia spp. was dominant species, and acclimation is also an important factor for the accerelated biodegradation.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.610-613
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• 2005

물리 화학적 원리에 의한 환경오염 정화방법은 종종 낮은 효율을 보이면서 공사비 부담은 큰 것으로 나타나고 있다. 그러나 생물학적 방법들은 이러한 단점들을 극복하면서 토양과 지하수를 정화할 수 있는 대안으로서 그 가능성을 입증하고 있는 실정이다. 그 중에서 생물학적 통풍법은 유류오염지역에 적용하고 있으며 그 원리는 지중 오염지역에 충분한 산소를 공급함으로서 오염성분이 토착 미생물에 의해 제거되도록 하는 것이다. 본 발표는 유류오염 지역에 적용된 생물학적 통풍법의 효율을 평가하여 제시하였다.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.392-401
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• 2006

In the July of 2006, devastating rainfalls ravaged the terrain in the province of Kangwon. These rainfalls resulted in debris flows, landslide and overflow over the habitat. Following these events, the urgent field study and countermeasures were to be needed and several methods were indicated. At each site, field observations were made and the properties of the channel and debris flow were broadly characterized. Debris flows are a natural hazard which looks like a combination of flood, land and rock slide. The same goes for that case, debris flow has been reported frequently overseas and the extent of damages has been increased. But the hazards "debris flow" is still insufficiently researched and futhermore debris flows are very hard to predict. In this paper, the general overview of the debris flow problem and the mitigation method will be presented

• Earthquakes and Structures
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• v.16 no.4
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• pp.375-389
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• 2019

During earthquakes, the performance of structures needs to be evaluated, which provides guidance for selecting suitable retrofitting schemes. The purpose of this paper is to accomplish seismic assessment of a simple steel residential building. Once the responses of the system are determined, the scope of the study extends to evaluate selected retrofitting strategies that are intended to rehabilitate the flaws of the structure under prescribed ground motions with high probability of occurrence at the site. After implementing the retrofits, seismic assessment of the upgraded structure is carried out to check if the remediation at various seismic performance levels is acquired or not. Outcomes obtained from retrofitted scenarios are compared to the results obtained from the initial un-retrofitted configuration of the structure. This paper presents the process for optimal selection of rehabilitation solutions considering the cost of implementation, downtime and disruption to property owners while improving the seismic performance level of the structure.

• Nuclear Engineering and Technology
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• v.54 no.5
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• pp.1781-1788
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• 2022

The containment building Kori Unit 1 may require sequential steps for full decommissioning. This study assumes that the containment building is to be used as an auxiliary building that handles nuclear power systems and materials during decommissioning before conversion into a greenfield. Through the derivation of guidelines and dose evaluation, it was confirmed whether the radiation workers were satisfied with the ALARA decision. The specific modeling of the external radiation exposure was performed based on the facility investigation procedures. The external radiation specific derived concentration guideline levels (DCGLs) for radiation workers in containment building were obtained using the RESRAD-BUILD code and were applied to the VISIPLAN 3D ALARA Planning Tool code to calculate the working dose and check worker safety. The derivation of site-specific and realistic DCGLs and dose evaluation via 3D modeling can contribute to the scenario development for the decommission and remediation of containment building.

• Journal of Korea Soil Environment Society
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• v.4 no.2
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• pp.193-201
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• 1999

This study was conducted to check the applicability of pilot-scale co-composting for the remediation of diesel contaminated soil during the winter. Nutrients and microbes were added to enhance the efficiency of bioremediation and fermenting composts were also added to stimulate the microbial activities. As a result. the soil pile was kept at adequate temperature for the bioremediation during the test period of 30∼40 days and initial concentration(2,340mg TPH/kg dry soil) was reduced to 216mg TPH/kg dry soil (approximately 91% removal). During the initial 10∼30 days, it was found that the TPH concentration and the microbial population were rapidly reduced and increased. respectively. The co-composting technology studied can be effectively applied to remediate the diesel contaminated soil during the winter.

• Journal of the Korean Geosynthetics Society
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• v.12 no.1
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• pp.29-38
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• 2013

This paper presents the analysis condition of remediation technique of contaminated fine-grained soil and physical properties of bio-degradable drain for analysis site applicability using bio-degradable drain method. As the result, two kinds of developed degradable drains (cylindricality shaped and harmonica shaped) are satisfied the Korean Industrial Standard. And the cylindricality shaped drain has an excellent discharge capacity than that of another one. By the results of laboratory test, the citric acid is chosen as the washing agent because it has low toxicity, so it is able to minimize harmful influence to environment. Furthermore the subject contaminants were selected as Cd, Cu and Pb. Based on the field pilot test results, the most remedial efficiency is the use of reactive material applied in bio-degradable drain method with the process of injecting the washing agent and extraction of contaminated fluid.

• Journal of Korean Society on Water Environment
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• v.24 no.1
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• pp.19-29
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• 2008

Hot air sparging is a groundwater remediation technique, in which organic contaminants volatilized into hot air from the saturated to vadose zone. In the laboratory diesel (10,000 mg TPH/kg) was spiked in contaminated saturated aquifer soil. The hot air ($34.9{\pm}2.7^{\circ}C$) was injected in intermittent (Q=1,500 mL/min, 10 minute injection and 10 minute idle) modes. We performed microcosm tests using the groundwater samples to assess TPH reductive remediation activity. For Terminal-Restriction Fragment Length Polymorphism (T-RFLP) analysis of eubacterial communities in sludge of wastewater treatment plants and soil of experiment site, the 16S rDNA was amplified by Polymerase Chain Reaction (PCR) from the sludge and the soil. The obtained 16S rDNA fragments were digested with Msp I and separated by electrophoresis gel. We found various sequence types for hot air sparging experiment with sludge soil samples that were closely related to Bacillus (149 bp, Firmicutes), Methlobacterium (149 bp, Euryarchaeotes), Pseudomonas (492 bp, ${\gamma}$-Proteobacteria), etc., in the clone library. In this study we find that TPH-water was reduced to 78.9% of the initial value in this experiment aquifer. The results of the present study suggests that T-RFLP method may be applied as a useful tool for the monitoring in the TPH contaminated soil fate of microorganisms in natural microbial community.

• Journal of Soil and Groundwater Environment
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• v.18 no.5
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• pp.56-64
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• 2013

After the law has been enacted for the prevention and recovery of mining damage in 2005, efforts of remediation have been started to recover heavy metal contaminated soils in agricultural land near mining sites. As part of an effort, the upper part of cultivation layer has been treated through covering up with clean soil, but the heavy metal contamination could be still spreaded to the surrounding areas because heavy metals may be remained in the lower part of cultivation layers. In this study, the most frequently occurring arsenic (As) contamination was selected to study in agricultural land nearby an abandoned metal mining site. We applied separation technologies considering the differences in the physical characteristics of soil particles (particle size, density, magnetic properties, hydrophobicity, etc.). Based on physical and chemical properties of arsenic (As) containing particles in agricultural lands nearby mining sites, we applied sieve separation, specific gravity separation, magnetic separation, and flotation separation to remove arsenic (As)-containing particles in the contaminated soil. Results of this study show that the removal efficiency of arsenic (As) were higher in the order of the magnetic separation, flotation separation, specific gravity separation and sieve separation.

• Korean Journal of Microbiology
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• v.49 no.4
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• pp.353-359
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• 2013

The objectives of this study were to investigate effectiveness of the Compressed Air Jet (CAJ) System for cleaning up shorelines contaminated with crude oils and to examine effects of the system on total petroleum hydrocarbon (TPH) removal and microbial community changes before and after remediation of the oil-contaminated shorelines. These data will lead to better understanding of optimized remediation process. About 66% of TPH reduction was observed when the contaminated site was treated with the CAJ System 2, 3, 4, and 5 times. This treatment system was more efficient than the seawater pumping system under similar treatment conditions (by 40%). By the way, little oil degrader communities were observed despite a potential function of the air jet system to stimulate aerobic oil degraders. The apparent low population density of the oil degraders might be as a result of low concentration of TPH as a carbon source and limiting nutrients such as nitrogen and phosphorus. It was proposed that the CAJ System would contribute significantly to removal of residual oils on the shorelines in combination with addition of these limiting nutrients.