• Journal of the Korean Society of Groundwater Environment
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• v.7 no.2
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• pp.73-88
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• 2000

The geochemistry of the $CO_2$-rich waters ($Pco_2\leq$about 1 atm) in NE part of the Kangwon province was investigated. The $CO_2$-rich waters can be divided to three types based on chemical compositions: Na-$HCO_3$, Ca-Na-$HCO_3$and Ca-$HCO_3$types. The water chemistry indicates that these type waters were evolved through reaction with host rocks by supply of deep-seated $CO_2$during deep circulation, and their geochemical environments in depth might have been different each other. The dissolution process of plagioclase is important in water/granite interactions and its solubility change according to reaction temperature played an important role in the determination of chemical compositions. The higher reaction temperature coincides with the lower different in solubility between albite and anorthite. It means that calcium is mainly released to the water in the lower temperature, whereas sodium in the higher temperature due to high Na/Ca ratio in plagioclase. The application of various chemical geothermometries on the $CO_2$-rich waters shows that the calculated reservoir temperature of Na-$HCO_3$type (about 15$0^{\circ}C$) is higher than those of Ca-$HCO_3$type. Therefore, we now interpret the recognized chemical difference was mainly due to the difference of reaction temperature. Considering normal thermal gradient, we can understand that the Na-$HCO_3$type was evolved from deeper crustal depth than the Ca-$HCO_3$type.

• The Korean Journal of Mycology
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• v.24 no.4 s.79
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• pp.310-321
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• 1996

Five strains AF027, AF069, AF2001, AF2011 and SD02 of Pseudomonas cepacia were isolated from soil, and the antifungal cyclic lipopeptides(CLP) i.e, CLP027A, CLP069A, Cepacidine A, CLP2011A and CLP02A were produced from each strains, respectively. Nitrogen and carbon sources in media were proved to be important factors for the production of CLP and among them, polypeptone-S, glucose and fructose were the most effective. It appeared that compounds CLP027A and CLP069A were identical with Cepacidine A and Xylocandine A, respectively. contain aspartic acid as amino acid component, are differentiated from Xylocandine A containing asparagine. Although molecular weight, amino acid composition and UV spectrum of CLP2011A and CLP02A are same with those of Cepacidine A, it is postulated that these compounds are not identical with Cepacidine A when the antifungal spectra and antifungal activity were compared to those of Cepacidine A.

• Economic and Environmental Geology
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• v.55 no.4
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• pp.339-352
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• 2022

As environmental criteria items are increased or strengthened, cases of heavy metal contamination by geogenic origin are increasing, and the need to distinguish between natural and anthropogenic origins in soil or groundwater exceeding the standard is increasing. In this study, geochemical occurrences of geogenic heavy metals were identified through statistical processing of the national geochemical map data and evaluation of geochemical characteristics of regions with high geoaccumulation indices. Cobalt, Cr, Cu, Ni, Pb, V, and Zn were targeted for which the national geochemical maps were prepared, and Co, Cr, Ni, and V derived from ultrabasic or ultramafic rocks were classified as factor 1. Copper, Pb and Zn of non-ferrous sulfide origin were classified as factor 2. In particular, enrichment of heavy metals by factor 1 occurs mainly in the serpentine distribution areas of the Chungcheong region, and there is a risk of contamination in neighboring areas. In the case of factor 2, geogenic occurrence is concerned not only in non-ferrous metal mineralization areas such as Taebacksan and Gyeongnam mineralization zones, but also in Au-Ag mineralization areas distributed nationwide.

• Journal of the Society of Disaster Information
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• v.13 no.3
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• pp.305-312
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• 2017

In our society, the advanced, advanced, and information industries have continued to grow and now live in the era of the fourth industrial revolution. As the industry develops, the load of the users has also increased so much that it is deepened by the energy shortage phenomenon and the construction of additional energy facilities is required. Therefore, energy plant construction work is being actively carried out in the coastal area. In particular, it is common to build a plant in the ground by filling the coast with soil in other regions, reflecting the fact that Korea is lacking in the country when constructing power plants, gas and petrochemical plants. Current domestic grounding designs are designed or constructed to suit only the use of grounding resistors based on the electrical equipment design technical standards. However, in the case of a plant facility constructed in the untested buried soil, when the lightning current and the abnormal current are inputted, the facility operator or the user due to the elevation of the ground potential is seriously exposed to the risk of electric shock disaster. In this paper, we analyze the ground resistivity of the landfilled soil and use a computer program (CDEGS) based on KS C IEC 61936-1, We analyze the contact voltage and stratification voltage and propose a grounding design optimized for plant installation.

• Journal of Soil and Groundwater Environment
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• v.13 no.1
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• pp.1-12
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• 2008

The purpose of this study is to characterize the hydrogeochemical characteristics of hot spring waters and to interpret the source of noble gases and the geochemical environment of the hot spring waters distributed along the eastern area of the Korean peninsula. For this purpose, We carried out the chemical, stable isotopic and noble gas isotopic analyses for eleven hot spring water and fourteen hot spring gas samples collected from six hot spring sites. The hot spring waters except the Osaek hot spring water show the pH range of 7.0 to 9.1. However, the Osaek $CO_2$-rich hot spring water shows a weak acid of pH 5.7. The temperature of hot spring waters in the study area ranges from $25.7^{\circ}C$ to $68.3^{\circ}C$. Electrical conductivity of hot spring waters varies widely from 202 to $7,130{\mu}S/cm$. High electrical conductivity (av., $3,890{\mu}S/sm$) by high Na and Cl contents of the Haeundae and the Dongrae hot spring waters indicates that the hot spring waters were mixed with seawater in the subsurface thermal system. The type of hot springs in the viewpoint of dissolved components can be grouped into three types: (1) alkaline Na-$HCO_3$ type including sulfur gas of the Osaek, Baekam, Dukgu and Chuksan hot springs, and (2) saline Na-Cl type of the Haeundae and Dongrae hot springs, and (3) weak acid $CO_2$-rich Na-$HCO_3$ type of Osaek hot spring. Tritium ratios of the Haeundae and the Dongrae hot springs indicate different residence time in their aquifers of older water of $0.0{\sim}0.3$ TU and younger water of $5.9{\sim}8.8$ TU. The ${\delta}^{18}O$ and ${\delta}D$ values of hot spring waters indicate that they originate from the meteoric water, and that the values also reflect a latitude effect according to their locations. $^3He/^4He$ ratios of the hot spring waters except Osaek $CO_2$-rich hot spring water range from $0.1{\times}10^{-6}$ to $1.1{\times}10^{-6}$ which are plotted above the mixing line between air and crustal components. It means that the He gas in hot spring waters was originated mainly from atmosphere and crust sources, and partly from mantle sources. The Osaek $CO_2$-rich hot spring water shows $3.3{\times}10^{-6}$ in $^3He/^4He$ ratio that is 2.4 times higher than those of atmosphere. It provides clearly a helium source from the deep mantle. $^{40}Ar/^{36}Ar$ ratios of hot spring water are in the range of an atmosphere source.

• Journal of Environmental Impact Assessment
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• v.31 no.5
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• pp.321-333
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• 2022

In this study, the concentration and distribution characteristics of BTEX (benzene toluene, ethylbenzene, and xylene) emitted from Daesan Petrochemical Industrial Complex were examined to determine their potential hazards to local residents. Residents living nearby the complex areas may be exposed to the chemicals through various media (air, water, and soil), especially by air. This study evaluated human health risks by inhalation using both deterministic and probabilistic risk assessment approaches. As a result of the deterministic risk assessment, the non-cancer risk was much lower than the regulation limit of hazard index (HI 1.0) for all the points. However, in case of cancer risk evaluation, it was found that the risk of excess cancer for benzene at point A located in the industrial complex was 2.28×10^-6, which slightly exceeded the standard regulatory limit of 1.0×10^-6. In addition, the probabilistic risk assessment revealed that the percentile exceeding the standard of 1.0×10^-6was found to be 45.3%. The sensitivity analysis showed that exposure time (ET) had the greatest impact on the results. Based on the risk assessment study, it implied that ethylbenzene, toluene, and xylene had little adverse effects on potential human exposure, but benzene often exceeded the cancer risk standard (1.0×10^-6). Further studies on extensive VOCs monitoring are needed to evaluate the potential risks of industrial complex areas.

• The Korean Journal of Pesticide Science
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• v.7 no.3
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• pp.176-181
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• 2003

The leaching behaviour of [aniline-$^{14}C$]mefenacet in soil was investigated using glass columns (5 cm I.D. $\times$ 30 cm. H) packed with two types of soils with different physicochemical properties. $^{14}C$-Mefenacet (8.33 kBq) and mefenacet (in total, 1.05 mg/kg) were treated onto soil columns and rice plants (Oryza sativa L.) were grown for 17 weeks on these columns. Leachates from the columns were collected at the rate of 122.5 mL per week. $^{14}C$-Activities leached from soil A (OM, 3.1%; CEC, 86 mmol(+)/kg; texture, loam) columns with and without rice plants were 1.95 and 4.19% of the originally applied, whereas those from soil B (OM, 1.3%; CEC, 71 mmol(+)/kg; texture, loam) were 2.69 and 7.05%, respectively. These results indicated that larger amounts of $^{14}C$ were percolated from soil B with less organic matter and from the columns without vegetation. $^{14}C$-Activities absorbed by rice plants from soil A and B were 8.95 and 8.47%, respectively, most of which remained in the root and shoot excluding unhulled grains and ears without grains. $62\sim73%$ of the originally applied $^{14}C$ remained in the depth of $0\sim5cm$ in soil. The mass balance indicated that the losses by volatilization and/or mineralization amounted to $3.4\sim9.2%$ of the originally applied. $^{14}C$-Radioactivities in the aqueous phase of the leachates ranged from 59.4 to 97.7% of the radioactivities in leachates, showing the fast transformation of mefenacet to the polar metabolites.

• Economic and Environmental Geology
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• v.41 no.1
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• pp.63-79
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• 2008

Physicochemical characteristics of stream water, leachate, mine water and groundwater were investigated to estimate the influences of the tailing and waste rock from the abandoned Uljin mine area. Total extraction analysis and mineralogical studies were carried out to understand sulfide weathering and to determine the distributions of trace elements in the soil affected by mine waste (tailing, waste rock and leachate). The pH and EC value of the leachate from the tailing disposal ranged 2.9-6.0, $99{\sim}3,990{\mu}S/cm$, respectively, and the concentrations of dissolved major (up to 492 mg/l Ca; 83.8 mg/l Mg; 45.2 mg/l Na; 44.7 mg/l K, 50.8 mg/l Si) and trace elements (up to $826,060{\mu}g/l$ Fe; $131,230{\mu}g/l$ Mn; $333,600{\mu}g/l$ Al; $61,340{\mu}g/l$ Zn; $2,530{\mu}g/l$ Cu; $573{\mu}g/l$ Cd; $476{\mu}g/l$ Pb) were relatively high. The stream water showed the variation of dissolved metal concentrations in seasonally and spatially. The dissolved metal contents of the stream water increased by influx the leachate from the tailing disposal, but these of the down stream have been considerably decreased by mixing of dilute tributaries. The dissolved metal concentrations of the stream water at dry season (as February) were lower than these at rainy season (as May and July). These represent that the amounts of the leachate varied with season. However, stream water could not be effectively diluted by confluence with uncontaminated tributaries, because the flux of tributaries and streams reduced at dry season. Thus attenuations by dilution had been dominantly happened in rainy seasons. The order of accumulations of trace element in soils compared with background values revealed Mn>Fe>Pb>Cu>Zn. Sulfide minerals were mainly pyrrhotite, sphalerite and galena and chalcopyrite. Pyrrhotite was rapidly weathered along the edge and fractures, and results in the formation of Fe-(oxy)hydroxides, which absorbed a little amount of Zn.

• Korean Journal of Plant Resources
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• v.19 no.1
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• pp.180-188
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• 2006

This study was carried out to offer the raw data on the method of cultivation and ecological characteristic by systematical analysing habitat environment of Tulipa edulis that was expected as medicinal and ornamental resource. The habitat environment was that the altitude was 245 m, the aspect of south, the size of approximately $49\;m^2$, and there was analyzed that Tulipa edulis grew wild in the dryly sunny spot. The vascular plants were summarized as 62 taxa; 28 families, 59 genera, 50 species, 11 varieties and 1 forms, and the resource plants were classified that there were 23 taxa of ornamental plants(37.1%), 43 taxa of edible plants(69.4%), 34 taxa of medicinal plants(54.8%) and 29 taxa of others(46.8%). In the results of soil factors analysis, there showed that acidity was pH 4.9, organic matter content of 4.9%, available $P_{2}O_{5}$ of 3.6 mg/kg, exchangeable $K^+$ of $0.5\;cmol^{+}/kg$, exchangeable $Ca^{2+}$ of $3.0\;cmol^{+}/kg$, exchangeable $Mg^{2+}$ of $0.8\;cmol^{+}/kg$, cation exchange capacity(C.E.C) of $12.3\;cmol^{+}/kg$ and electrical conductivity(EC) of 0.3 dS/m. In the results of correlation analysis between soil factors, exchangeable $Ca^{2+}$ and C.E.C were highly correlative. The growth characteristics of Tulipa edulis were surveyed that height was 7.6 cm, leaf width of 0.6 cm, leaf length of 12.7 cm, flower width of 2.8 cm, peduncle of 5.4 cm and chlorophyll of $34.7\;{\mu}g\;mg^{-1}$. In the results of correlation analysis between growth characteristics, height and peduncle were highly correlative. In the results of correlation analysis between soil factors and growth characteristics, exchangeable $K^{+}$ and leaf length were high relativity but they were confirmed negative relation. In the results of growth model analysis, R-square of leaf width and exchangeable $K^{+}$ was some 86.4% and that of chlorophyll and exchangeable $K^{+}$ was some 83.7%.

• Economic and Environmental Geology
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• v.38 no.5 s.174
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• pp.547-561
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• 2005

General characteristics of groundwater contamination by As were reviewed with several recent researches, and its occurrence in groundwater of Korea was investigated based on a ffw previous studies and a groundwater quality survey in Nonsan and Geumsan areas. In Bangladesh, which has been known as the most serious arsenic calamity country, about $28\%$ of the shallow groundwaters exceeded the Bangladesh drinking water standard, $50{\mu}g/L$, and it was estimated that about 28 million people were exposed to concentrations greater than the standard. Groundwater was characterized by circum-neutral pH with a moderate to strong reducing conditions. Low concentrations of $SO_4^{2-}$ and $NO_3^-$, and high contents of dissolved organic carbon (DOC) and $NH_4^+$ were typical chemical characteristics. Total As concentrations were enriched in the Holocene alluvial aquifers with a dominance of As(III) species. It was generally agreed that reductive dissolution of Fe oxyhydroxides was the main mechanism for the release of As into groundwater coupling with the presence of organic matters and microbial activities as principal factors. A new model has also been suggested to explain how arsenic can naturally contaminate groundwaters far from the ultimate source with transport of As by active tectonic uplift and glaciatiion during Pleistocene, chemical weathering and deposition, and microbial reaction processes. In Korea, it has not been reported to be so serious As contamination, and from the national groundwater quality monitoring survey, only about $1\%$ of grounwaters have concentrations higher than $10{\mu}g/:L.$ However, it was revealed that $19.3\%$ of mineral waters, and $7\%$ of tube-well waters from Nonsan and Geumsan areas contained As concentrations above $10{\mu}g/:L.$. Also, percentages exceeding this value during detailed groundwater quality surveys were $36\%\;and\;22\%$ from Jeonnam and Ulsan areas, respectively, indicating As enrichment possibly by geological factors and local mineralization. Further systematic researches need to proceed in areas potential to As contamination such as mineralized, metasedimentary rock-based, alluvial, and acid sulfate soil areas. Prior to that, it is required to understand various geochemical and microbial processes, and groundwater flow characteristics affecting the behavior of As.