• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.10a
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• pp.170-170
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• 2003

An initial study has been conducted with Korea Institute of Geoscience and Mineral resources and National Institute of Environment Research to evaluate the distribution of radon levels and their risk levels of groundwater in Korea. Probability distribution of 616 samples was log-normal one with 1,867pCi/L as arithmetic value, 920pCi/L as median and 40,010pCi/L as maximum during iou. years(1999-2002). In addition, 10% of total samples are in excess of 4,000pCi/L, 20% in excess of 2,700pCi/L, and 30% in excess of 1,700pCi/L, and 15 samples exceeds 10,000pCi/L. Total samples are grouped into 10 areas and 5 rocks unit, and difference of concentrations among areas and rocks are statistically significant(respectively, p<0.0001). The highest area is Daejeon located in ogcheon metamorphic rocks and granitic rocks, and most of all sites with high concentration sites are located in granitic rocks. The lowest area is Jeju located in volcanic rocks. We have estimated excess cancer risks of radon based on these data. To estimate risks, first of all, use patterns of groundwater are categorized with 6 groups: for drinking, household, farming, washing cars, raising stock, and others. We considered risk only for drinking water and household water because radon is rapidly dispersed before it of other use reach human respiratory organs. We select 565 samples for risk analysis, and applied unit risk which is 6.6210-7 per pCi/L to be recommended by NAS committee. Unit risk was derived from considering radon ingestion and radon inhalation from water use. When estimating risk, we analyzed PDF of concentration and represented risk as 50 and 95 percentile values to consider uncertainty with Monte-Carlo simulation. It results in 10-4 level of their excess cancer risk and in 10-2 level in some areas with high concentration of radon. It must be monitor periodically and take adequate actions in these risky sites. We recommend that it needs to take more survey and finally set guideline for radon regulation in groundwater.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.9
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• pp.654-659
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• 2013

This study was conducted to identify an optimal ratio of carbon to nitrogen (C/N ratio) for denitrification of nitrate using molasses as an external carbon source. A series of batch and column tests was conducted using an indigenous bacterium Pseudomonas sp. KY1 isolated from a nitrate-contaminated soil. For the initial nitrate-nitrogen concentration of 100 mg-N/L, batch test results indicated that C/N ratio of 3/1 was the optimal ratio with a relatively high pseudo-first-order reaction constant of $0.0263hr^{-1}$. At C/N ratio of 3/1, more than 80% of nitrate-nitrogen concentration of 100 mg-N/L was removed in 100 hrs. Results of column tests with a flow velocity of 0.3 mL/min also indicated that the C/N ratio of 3/1 was optimal for denitrification with minimizing remaining molasses concentrations. After 172 hrs of column operation (35 pore volumes) with an influent nitrate-nitrogen concentration of 100 mg-N/L, the effluent met the drinking water standard (i.e., 10 mg $NO_3$-N/L).

• Economic and Environmental Geology
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• v.42 no.3
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• pp.217-234
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• 2009

This study characterized groundwater quality and the influence of agrochemicals in a part of Ilgwang-Myeon agricultural area in Gijang-Gun, Busan Metropolitan City, using factor analyses. From the 1st, 2nd, and 3rd analyses of groundwater samples, the mean concentrations of $Ca^{2+}$, $Na^+$, $Mg^{2+}$, $K^+$, $Zn^{2+}$, $Cu^{2+}$, $Fe^{2+}$, $Al^{3+}$, $NO_3\;^-$, $Cl^-$, $SO_4\;^{2-}$, $F^-$, and $SiO_2$ were higher in the 2nd analysis than the other analyses. Pesticide carbofuran and herbicide alachlor were detected at the wells more than a half of all the wells in the 2nd analysis but not in the 4th analysis. This fact may be explained by that a higher precipitation induced higher infiltration rate of contaminants into groundwater during the 2nd survey. According to R- and Q-mode factor analyses, and chemical composition, inorganic constituents excepting $SiO_2$, $HC0_3\;^-$-, and $F^-$ may be influenced by anthropogenic sources (manures, synthetic fertilizers, and domestic wastes), seawater as well as water-mineral interaction. A typical indicator of groundwater contamination, nitrate, exceeds around 4-5 times over the Korean standard for drinking water. Additionally, the influence of seawater diminishes from the seaside to inland.

• 한국해양학회지
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• v.3 no.1
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• pp.26-38
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• 1968

Nutrients and principal ions contents in downstream water of the Han River, near Seoul, measured at somewhat three week intervals over a period of two years were shown its characteristic seasonal cycles. The annual ranges of nutrients were 0.5-7.7 $\mu\textrm{g}$ at/L of ammonia, 0.12-0.90 $\mu\textrm{g}$ at/L of nitrite, 2.9-35.9 $\mu\textrm{g}$ at/L of nitrate, 8.8-42.0 $\mu\textrm{g}$ at/L of tatal soluble nitrogen, 0.09-0.57 $\mu\textrm{g}$ at/L of phosphorus, and 3.0-15.3 mg/L of silicate, and these were lower in spring and fall closely correlate with phytoplankton blooms and higher in winter except ammonia and silicate contents. Annual variations of BOD and COD were 0.10-2.14 ml/L, 0.88-6.82 mg/L, respectively. The ionic concentrations of Cl, Ca and Mg were not high of which Cl 5.0-13.1 mg/L, Ca 3.7-9.1 mg/L and Mg 1.5-10.4 mg/L of annual ranges. Fe ranged 18.5-82.8 $\mu\textrm{g}$/L, Mn 15-58 $\mu\textrm{g}$/L, Cu 0.3-4.7 $\mu\textrm{g}$/L annually In general, the Han River water is low in nutrients, mineral contents, and may be said not yet polluted, excellent quantity and quality of river water.

• Journal of Plant Biotechnology
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• v.39 no.4
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• pp.281-287
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• 2012

This experiment was conducted to investigate the effect of various type of Magma seawater (MSW) concentrations on plant growth and useful mineral contents in Bletilla striata. In the RO (Reverse Osmosis) and ED (Electronic Distal) treatment, hardness of medium was poored in 3.0 g/L gelrite but increased in 8.0 g/L plant agar, 38,000 and $2,000g/cm^2$ respectably. We analyzed the morphological and physiological characteristics differences of B. striata treated various MSW. Survival frequency of plant and growth (shoot length, shoot diameter, root length, root diameter, shoot/root ratio) were significantly increased in RO and ED treatment at 50% and 10%, especially. Chlorophyll contents in ED treatments were higher than those in control and RO treatment. The content of strontium (Sr) in 20, 50, 75, 100% ED treatment, were higher than those in the control and RO, ED 1, 5, 10% treatment. These results showed that treatment of ED with the range of 20~100% could be used to supply the strontium enriched orchid plant. It is considered that MSW may be applied for use in Magma seawater to promotion of growth and produced functional plant.

• The Korean Journal of Food And Nutrition
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• v.5 no.2
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• pp.84-89
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• 1992

Concentrations of major minerals(Ca, p, Na, K, Mg) and trace elements (Fe, Zn) were measured in human milk samples collected from 19 selected, healthy lactating women at 2~5 days, and at 4, 8 and 12 weeks postpartum. Decreases in the contents of m) or minerals and trace elements were found with the increase of time postpartum. Mean Ca contents of 2~5 days, 4 week, 8 week and 12 week in human milk were 243.02$\pm$50.90ug/ml, 295.0$\pm$65.70ug/ml, 295.0$\pm$41.50ug/ml, 349.90$\pm$83.50ug/ml, respectively And mean P contents of 2~5 days, 4 week, 8 week and 12 week in human milk were 134.70$\pm$49.4ug/ml, 134.90$\pm$19.70ug/ml, 117.60$\pm$18.90ug/ml, 130.60$\pm$28.20ug/ml, respectively. Ca/P of them were 1.81, 2.19, 2.20, 2.68, respectively. Mean Mg contents of them were 22.30$\pm$5.60ug/ml, 25.70$\pm$3.70ug/ml, 25.10$\pm$3.60ug/ml, 32.10$\pm$4.50ug/ml, respectively. And mean Na contents of them were 171.20$\pm$90.50ug/ml, 158.70$\pm$47.00ug/ml, 104.50$\pm$24.70ug/ml, 115.90$\pm$12.50ug/ml, respectively. Mean K contents of them were 506.10$\pm$156.10ug/ml, 520.90$\pm$55.00ug/ml, 370.10$\pm$29.00ug/ml, 468.40$\pm$75.70ug/ml, respectively. Na/K of them were 0.34, 0.30, 0.28, 0.25, respectively. Mean Fe contents of them were 2.80$\pm$1.80ug/ml, 2.70$\pm$0.40ug/ml, 2.60$\pm$0.40ug/ml, 2.10$\pm$0.10ug/ml, respectively. And mean Zn contents of them were 3.70$\pm$1.60ug/ml, 2.78$\pm$9.70ug/ml, 2.70$\pm$0.70ug/ml, 2.30$\pm$0.20ug/ml, respectively, These determinations will provide the basic information on the variability of major minerals and trace elements as lactation proceeds and on the composition of components between term and preterm milk.

• Korean Journal of Organic Agriculture
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• v.20 no.3
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• pp.313-326
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• 2012

The aim of this study was to determine the effect of effective microorganisms (EM) on growth, yield and fruit nutrient contents of two cultivars ('Muhanjilju' and 'Daetong') of hot pepper. The number of injection of EM cultivated are 6 times from the pepper plant seedlings until harvested in both cultivars. Stem girth was highest in the treatment of Lactobacillus plantarum whereas lowest in no EM control. In 'Muhanjilju', the number of branches was highest (79.3) in the treatment of Bacillus subtilis whereas in 'Daetong' was highest (119.0) as treated with Lactobacillus plantarum. Yield of the red hot pepper fruits that sum of two varieties was highest in the treatment of Rhodopseudomonas capsulatas (53.1kg FW per 10a). Regardless of EM treatments, average yield was 8% higher in 'Daetong' than is 'Muhanjilju' (33.8kg vs 31.2kg per 10a). The incidence of antracnose was lowest by the Rhodopseudomonas capsulatas treatment, which led to the highest yield. As for the effect on fruit mineral nutrients, total N and phosphorus concentrations were highest in the treatment of Lactobacillus plantarum and Bacillus subtilis in both varieties, respectively. The highest content of total carotenoids was obtained from the treatment of Lactobacillus plantarum in both varieties.

• Korean Journal of Organic Agriculture
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• v.20 no.3
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• pp.357-368
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• 2012

This study was conducted to evaluate soil inorganic N concentrations and N uptake efficiency of sorghum ${\times}$ sudangrass hybrid (Sorghum bicolor (L.) Moench) as affected by organic nutrient sources from 2009 to 2011. The treatments included chemical fertilizer, compost, oilcake, alfalfa hay mulch, and control. Nutrient applications were made at rates equivalent to approximately 210 kg of actual N per hectare. The precipitation during the growth period from May to September was higher in 2011, followed by 2009, and 2010. Oilcake had the lowest C:N ratio in the raw materials. Compost treatment slowed N-mineralization rate in soil during the measured years. Soil mineral nutrition and dry matter production were not consistently affected by treatments, but the dry matter production was negatively correlated with the amount of precipitation from May to September for three years. Chemical fertilizer treatment increased N efficiency in plants in the first two years, observing with lower N efficiency in plants treated with compost for 3 years. Increased precipitation from June to August improved N efficiency in sudangrass plants treated with compost but reduced the efficiency with the chemical fertilizer. Total dry matter production and N efficiency in plants were not affected by the C:N ratio of the raw materials rather than weather condition.

• Economic and Environmental Geology
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• v.43 no.4
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• pp.371-379
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• 2010

Fresh water injection test in a fractured bedrock aquifer was applied as an efficient approach to lower saline concentrations in the saltwater-freshwater transition zone formed by seawater intrusion in a coastal area. The methodology and effectiveness of fresh water injection for hydraulically controlling seawater intrusion is overwhelmingly site dependent, and there is an urgent need to characterize the permeable fractures or unconsolidated porous formations which can allow for seawater flow and transport. Considering aquifer characteristics, injection and monitoring boreholes were optimally designed and completed to inject fresh water through sand layer and fractured bedrock, respectively. We devised and used the injection system using double packer for easy field operation and maintenance. Overall fracture distribution was systematically identified from borehole image logs, and the section of fresh water injection was decided from injection test and monitoring. With fresh water injection, the fluid electrical conductivity of the monitoring well started to be lowered by the inflow of fresh water at the specific depth. And this inflow leaded to the replacement of the fluid in the upper parts of the borehole with fresh water. Furthermore, the injection effect lasted more than several months, which means that fresh water injection may contribute to the mitigation of seawater intrusion in a coastal area.

• Economic and Environmental Geology
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• v.53 no.4
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• pp.337-346
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• 2020

This study was carried out to evaluate the applicability of the soil washing process to remediation mercury-contaminated mine tailing or solid material (soil and sediments etc.) around abandoned mines. First, the physicochemical characteristics of mine tailing were analyzed through particle size analysis and sequential extraction. Secondly, laboratory scale washing experiments were performed using hydrochloric acid, nitric acid, potassium iodide and sodium thiosulfate. As a results of particle size analysis, mine tailing particle were concentrated below 40 mesh and the particle size below 200 mesh was the most analyzed. As a result of sequential extraction, elemental mercury fraction was analyzed as the highest with 69.12%, with strongly bound fraction 15.25% and residual and HgS fractions 11.97%, respectively. Laboratory scale washing experiments showed low applicability for nitric acid and sodium thiosulfate solutions. In case of hydrochloric acid solution, it was analyzed that mercury removal was possible at particle size of 200 mesh or more. Therefore, it is considered to be performed together with the physical sorting process. Potassium iodide solution was analyzed to have high washing efficiency at all concentrations and particle sizes. In particular, the mercury removal efficiency is high in the micro particles, and thus the applicability of the washing technology is the highest.