• Journal of Environmental Impact Assessment
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• v.18 no.6
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• pp.435-443
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• 2009

Ba Ria - Vung Tau province in Southern Vietnam is one of the fastest economic growing areas in the country, characterized by the rapid port and industrial development along the Thi Vai river. The socio-economic situation of the area has generally been improved; however, its part of the local inhabitants has not gained benefits from the changes. 35 surface water samples and 25 sediment samples were analysed with the interpretation of the SPOT images for 1995 and 2005. The data showed that rapid port and industrial development have resulted in significant losses of mangroves and agriculture land. The surface water was seriously polluted, particularly in terms of organic materials and suspended solids. It contained high and increasing oil concentrations. The river sediment was saline and slightly alkaline. It was heavily reduced, organic-rich, and contaminated with oil and heavy metals (Cu, Pb, and Cr).

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.129-135
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• 2000

Four types of land use were selected for sampling and study with different characteristics of heavy metal contamination during the period from August 1998 to June 2000. A series of studies have been carried out concerning the physicochemical characteristics of the sediments settling down in a gully pot to evaluate the contamination of Pb, Zn, Cd, Co, Cr and Cu. An examination of six elements indicated that Zn, Cu and Pb were the heavy metals severely impacted by anthropogenic input in Seoul. An assessment of 60 volatile organic compounds (VOCs) in urban runoff and ground water was conducted based on samples collected from 31 sites and 12 wells, respectively, in Seoul City. The higher levels of alkyl benzenes in urban runoff indicated that Seoul areas were mainly contaminated through traffic sources.

• Journal of environmental and Sanitary engineering
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• v.12 no.2
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• pp.65-74
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• 1997

The purpose of this study was to investigate the removal effect and variation of contaminated water by various water treatment processes using sediment filter, activated carbon, photocatalysis, reverse osmosis, ultra violet sterilizer and ultra filtration. The removal effect of chloride and trace metal was low by activated carbon and ultra filter but high in reverse osmosis. The removal effect of bacteria and E. coli was low by activated carbon and membrane filter system using activated carbon but high in impregnated activated carbon. The removal effect of TCE was low in sand and ultra filter system as compared with activated carbon. Ultra filtration process was effective for purify agricultural water without E.coli. Reverse osmosis was effective to remove heavy metal and activated carbon was effective to remove halogenated organic chemical compound. The flux and the removal effect of COD in spiral wound ultrafilter were higher than the hollow fiber ultrafilter.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.405-407
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• 2005

To evaluate the main hydrogeochemical characteristics, river waters are investigated using element리 and isotopic compositions in South Korea. In this area, the chemical compositions are mostly classified into three groups; $Ca^{2+}-{HCO_3}^-$ type, $Ca^{2+}-Cl^{-}-{NO_3}^-$ type and $Ca^{2+}-{HCO_3}^{-}-Cl^{-}-{NO_3}^-$ type. These types are affected by two major factors: water-rock interaction and anthropogenic inputs such as sewage and fertilizers. Based on the values of ${\delta}^{18}O$ and ${\delta}D$, most of waters are originated from precipitation except two samples contaminated. The lithology and geography of basins mainly control the water chemistry. Elemental and isotopic compositions show that water chemistry are mainly controlled by three end members, especially by carbonate dissolution, and suggest that anthropogenic input affect the water chemistry. Also, three weathering sources are identified: silicates, dolomite and limestone.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.316-319
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• 2005

Contaminated area should be identified for designing polluted groundwater cleanup plan. A methodology was suggested to identify a contaminant plume distribution geostatistically. James & Gorelick (1994) suggested a methodology to evaluate data worth as expected reducing remediation cost. In this study, their methodology was modified to evaluate data worth as expected reducing uncertainty of the contaminant plume distribution. In suggested methodology, the source identification model by Mahar & Datta (2001) using a forward solute transport model is integrated. Suggested methodology was assessed by two simple example problems and its result represented reducing uncertainties of contaminant plume distribution successfully.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.397-400
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• 2003

In this study, humic and fulvic acids in soils at the vicinity of domestic atomic power plants(NPPs), located in Yungkwang(YK), Uljin(UJ), Kori(KR), Koseong(KS), Wolseong(WS) area, and in volcanic ash soils of the Cheju island(Mt. Hanla(HL), Manjanggul(MJ)) were isolated, and characterized using chemical(elemental analysis, proton exchange capacity, molecular size distribution) and spectroscopic(UV/Vis., IR, FL, $^{13}$ C NMR spectra) methods. The results were compared with one another and compiled for their DB establishments. The humic substances distribution (humic acid, fulvic acid, Humin) in the soils were also determined by IHSS standard method. Main purpose of this study was to provide a basic data needed to evaluate the effect of humic substances on the migrational behaviour of radioactive elements in contaminated surface soil.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.124-127
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• 2003

Laboratory scale experiments on in-situ ozonation were carried out to delineate the effects of liquid phases, such as soil water and nonaqeous phase liquid (NAPL) on the transport of gaseous ozone in unsaturated soil. Soil water enhanced the transport of ozone due to water film effect, which prevent direct reaction between soil particles and gaseous ozone, and increased water content reduced the breakthrough time of ozone because of increased average linear velocity of ozone and decreased air-water interface area. Diesel fuel as NAPL also played a similar role with water film, so the breakthrough time of ozone in diesel-contaminated soil was significantly reduced compared with uncontaminated soil. However, ozone breakthrough time was retarded with increased diesel concentration, because of high reactivity of diesel fuel with ozone. In multiphase liquid system of unsaturated soil, the ozone transport was mainly Influenced by nonwetting fluid, diesel fuel in this study.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.909-910
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• 2007

The volatile organic compounds exposure is governed by the source distance and dispersion of the pollutant into air and groundwater. The purpose of this study was to validate suggested models for the prediction of concentration distributions. The study design was organized into different methods to simulate industry site. The distribution models generally showed a fair agreement with measured data. For graphical representation of concentration of volatile hydrocarbon, it has to obtain a continuous representation of the contamination of the site. Therefore, the used interpolative methods examined for this project are the IDW(inverse Distance Weighting) and kriging method. In the results, in summary, all two different methods can be used to quantify exposures at a particular source area, and thus provide, a solid foundation for making risk-based decisions. All the calculations can be performed using Excel's built-in functions, and the capabilities of geospatial analysis allow the results to be displayed visually. However, anyone who uses these methods should understand all of the assumptions and limitation.

• Nuclear Engineering and Technology
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• v.52 no.11
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• pp.2511-2521
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• 2020

The Fukushima accident is characterized by the fact that three reactors at the same site experienced reactor vessel failure and the accident resulted in significant radiological release to the environment, which was about 1/10 of the Chernobyl releases. The safe removal of fuel debris in the reactor vessel and Primary Containment Vessel (PCV) and treatment of huge amount of contaminated water are the major issues for the decommissioning in coming decades. Discussions on the new researches efforts being carried out in the area of investigation of the end state of fuel debris and Boling Water reactor (BWR) specific core melt progression, development of technologies for the mitigation of radiological releases to comply with the strengthened safety requirement set after the Fukushima accident are discussed.

• Journal of Korea Water Resources Association
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• v.53 no.6
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• pp.463-467
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• 2020

The main feature of this study is to automatically synthesize square images by sending aerial photographs and images from unmanned aerial vehicles (drons). It may be applicable to the cloud server, and to apply analytical algorithms for the suitable purpose of image processing. Drone imaging analysis is a process that can be used in various fields such as finding contaminated area of green algae, monitoring forest fire, and managing crop cultivation.