• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.53-57
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• 2018

고도의 산업화에 따라 도시의 성장과 인구의 밀집으로 인하여 물의 수요가 증가하고 이에 따라 각종 오염원의 유입이 증가함에 따라서 적절한 수질 관리에 대한 필요성이 대두되고 있다. 그리고 산업이 다양화됨에 따라 배출되는 하 폐수의 특성도 다양해져 기존의 수질처리장은 효율적인 처리를 하는데 있어 많은 어려움이 발생되고 있다. 굴 패각은 하수처리의 담체로 이용할 경우 살수여상의 문제점 중 하나로 나타나는 막힘 현상을 다소 감소시킬 수 있고, 다공질체로서 표면적이 불규칙하고 비표면적이 크기 때문에 반응기내에 공기를 원활하게 공급할 수 있으며, 중금속 이온과 유기물에 대한 흡착 효율이 뛰어나 미생물이 쉽게 부착, 성장할 수 있는 장점을 가지고 있다. 천연광물질은 전 세계적으로 발견되어 활용된 역사가 짧지만, 그 특징은 산소결핍보충, 유해원소 흡착 성능, 반도체 작용, 인체 면역력 강화, 바이러스성 질병의 예방, 중금속 해독 등의 다양한 특징으로 환경호르몬 제고, 음이온 원적외선 발생으로 세포의 노화방지, 인체 노폐물 제거와 같은 특징을 지닌 매우 유용한 자원으로 확인되고 있으며, 수질정화 능력이 탁월한 것으로 보고 있다. 이에 본 연구는 어촌폐기물인 굴 패각과 수질정화에 탁월한 천연 광물질을 혼합하여 경제적이고, 효율성이 높은 다공성 수질개선 담체를 개발하고, 수목여과용 비점오염시설 장치에 적용하여 혼합 담체가 수처리 시설의 담체로서 사용이 가능한지, 수목여과용 비점오염시설 장치에 적용할 수 있는지 검토하고자 수행하였다. 이 연구는 2017년 중소기업청 기술개발사업에서 연구지원을 받아 연구되었습니다.

• Nuclear Engineering and Technology
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• v.54 no.11
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• pp.4005-4012
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• 2022

As high-level radioactive waste (HLW) generated from nuclear power plants is harmful to the human body, it must be safely disposed of by an engineered barrier system consisting of disposal canisters and buffer and backfill materials. A gap exists between the canister and buffer material in a HLW repository and between the buffer material and natural rock-this gap may reduce the water-blocking ability and heat transfer efficiency of the engineered barrier materials. Herein, the basic characteristics and thermal properties of granular bentonite, a candidate gap-filling material, were investigated, and their effects on the temperature change of the buffer material were analyzed numerically. Heat transfer by air conduction and convection in the gap were considered simultaneously. Moreover, by applying the Korean reference disposal system, changes in the properties of the buffer material were derived, and the basic design of the engineered barrier system was presented according to the gap filling material (GFM). The findings showed that a GFM with high initial thermal conductivity must be filled in the space between the buffer material and rock. Moreover, the target dry density of the buffer material varied according to the initial wet density, specific gravity, and water content values of the GFM.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.1
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• pp.47-55
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• 2015

Recently, the production of taste and odor (T&O) compounds is a common problem in water industry. Geosmin is one of the T&O components in drinking water. However, geosmin is hardly eliminated through the conventional water treatment systems. Among various advanced processes capable of removing geosmin, adsorption process using granular activated carbon (GAC) is the most commonly used process. As time passes, however GAC process changes into biological activated carbon (BAC) process. There is little information on the BAC process in the literature. In this study, we isolated and identified microorganisms existing within various BAC processes. The microbial concentrations of BAC processes examined were $3.5{\times}10^5$ colony forming units (CFU/g), $2.2{\times}10^6CFU/g$ and $7.0{\times}10^5CFU/g$ in the Seongnam plant, Goyang plant and Goryeong pilot plant, respectively. The dominant bacterial species were found to be Bradyrhizobium japonicum, Novosphingobium rosa and Afipia broomeae in each plants. Removal efficiencies of $3{\mu}g/L$ geosmin by the dominant species were 36.1%, 36.5% and 34.3% in mineral salts medium(MSM) where geosmin was a sole carbon source.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1034-1040
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• 1998

The nutritional quality and physiological activity of cultivated hoelen from 13 months to 24 months were examined to compare with natural hoelen. General compositions of hoelen were as follows re spectively; crude protein 1.80~2.50%, crude fat 0.68~1.23%, crude ash 0.12~0.43%, crude fiber 6.30~7.14%, nitrogen free extract 89.25~90.44%. The major free sugar was glucose, and the content of 13 months cultivated hoelen was higher than any other cultivated hoelen. The major fatty acids of hoelen were linoleic acid, palmitic acid, stearic acid and oleic acid. The ratio of unsaturated fatty acids was 62.62~77.96% and the content was higher in cultivated hoelen than in natural hoelen. The contents of amino acid were high in the order of tyrosine, aspartic acid, glutamic acid and serine, and increased as the day of cultivation became longer. The contents of mineral components were higher in the order of Ca, K, Mg and the contents of Na and Ca were higher in natural hoelen than in cultivated hoelen. The contents of pachymic acid and dehydropachymic acid was similar in the natural and cultivated hoelen. On the results of antimicrobial test the ethanol extract showed a stronger effect than water extract, and had an excellent antimicrobial activity on Micrococcus luteus and Escherichia coli. The ethanol extract of hoelen showed comparatively strong electron donating ability. The ethanol extract of hoelen showed a high inhibition activity on the growth of lung cancer, ovary cancer, skin cancer, central nerve cancer and rectum cancer, especially the activity of 19 months cultivated hoelen was the highest. On the above results of nutritional quality and physiological activity of hoelen, it is supposed that the picking date of cultivated hoelen was suitable over than 19 months.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.50-53
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• 2006

Regional geophysical surveys and geological cal studies on natural gas hydrate (NGH) in the East Sea were carried out by the Korea Institute of Geoscience and Mineral Resources (KIGAM) from 2000 to 2004. 16 piston cores, 2270 L-km of multi-channel reflection seismic (MCRS) data and 730 L-km of 3.5kHz Chirp data obtained from the southwestern part of the deep-water Ulleung Basin were analyzed in this study. In piston cores, cracks generally developed parallel to bedding suggest significant gas content. The core analyses showed high total organic carbon (TOC) content, sedimentation rate and heat flow of sediments. These are in favor of the general ion of substantial biogenic methane, which can form the NGH within the stability zone of the near seafloor sediments in the study area. The cores generally show also high residual hydrocarbon gas concentrations for the formation of natural gas hydrates The geophysical indicators of the presence of gas and/or NGH such as bottom simulating reflectors (BSRs), seismic blank Bones, pockmarks and gas seeping features were well defined on the MCRS and Chirp data.

• Journal of Life Science
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• v.18 no.3
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• pp.329-335
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• 2008

Korean Deep ground sea-like water (KDSW) has a similar mineral composition with deep sea water. KDSW has demonstrated its usefulness and attracted in the medical fields. KDSW and Danasoo (desalted deep ground sea-like water) intake improve antioxidant, antidiabetic activity and immunity. Antioxidant activities of KDSW and Dnansoo were measured by using 2,2-diphenyl-l-picryl-hydrazyl (DPPH) free radical, superoxide dismutase-like activity (SODA) and photochemiluminescence (PCL). DPPH radical scavenging and SOD-like activities of KDSW and Danasoo were remarkably increased in a dose-dependent manner. Antioxidant activities of KDSW and Danasoo 85.32 and 14.02 nmol of ascorbic acid equivalent/ml KDSW and Danasoo, respectively, using the PCL method. Lipopolysaccharide (LPS)-induced nitric oxide (NO) production in macrophages RAW264.7 cells was inhibited up to 30% by treatment with Danasoo (20%). NO is synthesized by the enzyme of nitric oxide synthase (NOS) and plays an important role tumor growth and angiogenesis. The anticancer effects of Danasoo on human gastric and lung cancer cells was performed by levels of inducible nitric oxide synthase (iNOS). Danasoo significantly reduced iNOS expression of human gastric cancer (SNU-l) and lung carcinoma (A549). The serum glucose level was significantly reduced by Danasoo (20%) diet in streptozotocin (STZ)-induced diabetic rats. These result suggest that KDSW has excellent biological activities and thus it has great potential as a source for natural health products.

• The Journal of Engineering Geology
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• v.31 no.2
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• pp.165-178
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• 2021

The influence of Soil-Water Characteristic Curve (SWCC) fitting parameters for an unsaturated natural slope was evaluated through seepage and slope stability analysis as a function of rainfall. Soil samples were collected from the study area in Jirisan National Park and the physical and mechanical characteristics of unsaturated soil layers were measured in laboratory tests. The saturation depth was calculated via seepage analysis by changing fitting parameters α, the parameter related to the Air Entry Value (AEV) and n, the parameter related to the slope of the SWCC in the range of natural conditions. Slope stability analysis using the limit equilibrium method considered the calculated depth of saturation. Results from seepage analysis for various rainfall conditions indicate the saturation depth in the soil layer suddenly increased as the fitting parameter α decreased; the saturation time for the entire soil layer also decreased. Slope stability analysis considering the calculated depth of saturation shows that the slope safety factor rapidly decreased as the fitting parameter α decreased, whereas the variation in slope safety factor was very small when n increased. Hence, fitting parameter α has a large effect on saturation depth during rainfall and therefore on slope stability, whereas slope stability is relatively unaffected by the fitting parameter n.

• Economic and Environmental Geology
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• v.40 no.4
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• pp.403-418
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• 2007

The objective of this research was to characterize the fate and transport of Cr(VI) contaminated groundwater in the Daejeon industrial area. Five subsidiary monitoring wells were newly installed and two existing wells were utilized for the investigation and the reduction process of Cr(VI) contaminated groundwater of the Daejeon(Mun-pyeong) national groundwater monitoring station. The Cr(VI) concentrations at the shallow aquifer well of the station were in the range of 3.2-4.5 mg/L indicating continuous contamination. However, Cr was not detected at the deep bedrock well and the other monitoring wells except MPH-1 and 3. The Cr(VI) concentrations of MPH-1 and MPH-3 were below the drinking water guideline value (0.05 mg/L). Therefore, the plume of the Cr(VI) contaminated groundwater was predicted to be confined within the narrow boundary around the station. The soluble/exchangeable Cr(VI) concentrations were below the detection limit in all core and slime samples taken from the five newly installed wells. Although the exact source of contamination was not directly detected in the study area, the spatial Cr(VI) distribution in groundwater and characteristics of the core samples indicated that the source and the dispersion range were confined within the 100 m area from the monitoring station. The contamination might be induced from the unlined landfill of industrial wastes which was observed during the installation of an subsidiary monitoring well. For the evaluation of the natural attenuation of Cr(VI), available reduction capacities of Cr(VI) with an initial concentration of 5 mg/L were measured in soil and aquifer materials. Dark-gray clay layer samples have high capacities of Cr(VI) reduction ranging from 58 to 64%, which is obviously related to organic carbon contents of the samples. The analysis of reduction capacities implied that the soil and aquifer materials controlled the dispersion of Cr(VI) contamination in this area. However, some possibilities of dispersion by the preferential flow cannot be excluded due to the limited numbers of monitoring wells. We suggest the removal of Cr(VI) contaminated groundwater by periodical pumping, and the continuous groundwater quality monitoring for evaluation of the Cr(VI) dispersion should be followed in the study area.

• Korean Journal of Ecology and Environment
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• v.44 no.1
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• pp.31-41
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• 2011

To optimize the natural chemical agents against nuisance phytoplankton, we examined algal removal activity (ABA) of Plant-Mineral Composite (PMC), which already developed by our teams (Kim et al., 2010), on various conditions. The PMC are consisted of extracted-mixtures with indigenous plants (Camellia sinensis, Quercusacutissima and Castanea crenata) and minerals (Loess, Quartz porphyry, and natural zeolite), and characterized by coagulation and floating of low-density suspended solids. A simple extraction process was adopted, such as drying and grinding of raw material, water-extraction by high temperature-sonication and filtering. All tests were performed in 3 L plastic chambers varying conditions; six different concentrations ($0{\sim}1.0\;mL\;L^{-1}$), six light intensities ($8{\sim}1,400\;{\mu}mol\;m^{-2}s^{-1}$), three temperatures ($10{\sim}30^{\circ}C$), four pHs (7~10), five water depths (10~50 cm), and three different waters dominated by cyanobacteria, diatom, and green algae, respectively. Results indicate that the highest ABA of PMC was seen at $0.05\;mL\;L^{-1}$ in treatment concentrations, where showed a reduction of more than 80% of control phytoplankton biomass, while $1,400\;{\mu}mol\;m^{-2}s^{-1}$ in light intensity (>90%), $20{\sim}30^{\circ}C$ temperature (>60%), 7~9 in pH (>90%), below 50 cm in water depth (>90%), and cyanobacterial dominating waters (>80%), respectively. Over the test, ABA of PMC were more obvious on the algal biomass (chlorophyll-${\alpha}$) than suspended solids, suggesting a selectivity of PMC to particle size or natures. These results suggest that PMC agents can play an important role as natural agents to remove the nuisant algal aggregates or seston of eutrophic lake, where occur cyanobacterial bloom in a shallow shore of lake during warm season.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.2
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• pp.45-58
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• 2006

This study was aimed to propose the plan of creating a biotope reflecting an ecological education as well as its function as the habitats of amphibian in Namsan Urban Natural Park in Seoul. There were Cheonil mineral spring area which was located on the southern side of Namsan, wetlands which was already created on the east valley(800$m^2$) and a buffer area of the circumference(1,100$m^2$) as the biotope sites. Major fields of this study include a survey of the staus, a basic plan, a master plan; a survey of this site was focused on topography, water system, existing vegetation, wildbird, amphibian, trail; a detailed plan was focused on flow plan, planting plan, facility plan. Existing vegetation was classified into 8 types; Pinus densiflora forest, Pinus densiflora planted area, Prunus sargentii-Quercus spp. forest, Pinus rigida forest, Robinia pseudoacacia forest, artificial green space, wetlands, south beltway. There were Pinus densiflora planted area and Prunus sargentii-Quercus spp. forest as major vegetations of this site. 14 species and 33 individuals of wildbirds appeared, Rana temporaria ornativentris and Hynobius leechi were investigated in the wetlands.In particular, habitats of amphibian were divided eco-zone, buffer-zone and restore-zone, and habitats and facilities which would be suitable for the characteristics of each space were planned. As a result, environment elements of good habitats including spawn wetlands of amphibian, harbor of amphibian, water plant of wetland, wild shrubs forest, ecological landscape forest, wetland observation trail, fence of wetland protection and ramp by pebble and log were created at the site. The amphibian biotope of Namsan is rated high as an important space for conserving biodiversity. Accordingly, continuous monitoring of this biotope as a urban habitat is required as the environment changes.