• Journal of the Korean earth science society
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• v.27 no.1
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• pp.73-82
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• 2006

Dust samples were collected from 10 middle and high schools in the Gochang-Gun, Korea. Heavy metal concentrations were determined for the dry-deposited dusts from indoor and outdoor of classroom and playground of each sampling site. Concentrations of Cd, Cu, Pb and Zn in indoor's dusts were highly concentrated. Also concentrations of Cu, Ni, Pb and Zn in outdoor's dusts were highly concentrated. Concentrations of Cd, Cu and Zn in the dusts were much higher than the world average contents in soil and environmental orientation value. These levels are similar to those of the dust samples at middle schools and high schools located in Jeonju-city, Korea. Compared with concentrations of heavy metals in soils and dusts in Korea, the environment of indoor and outdoor of classroom is highly concentrated except for Cu, Zn. The concentrations of playground is less than that of residential dust and main road dust and playground in Jeonju-city. Playground dusts in 1 school exhibited the enhanced heavy metal pollution with a pollution index (Kloke, 1979) greater than 1.0, but indoor and outdoor dusts in 7 schools exhibited the enhanced heavy metal pollution with a pollution index (by Kloke) yester than 1.0.

• Journal of the Korean Society of Groundwater Environment
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• v.5 no.1
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• pp.1-9
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• 1998

Schlumberger soundings and dipole-dipole electrical surveys were carried out in and around the Nanjido waste landfill in August and December, 1995. Survey points were set to be identical as those in August, 1994 and February, 1995 as possible. To elucidate the annual variation of resistivity structure in and around the landfill, 50 electrical soundings and 2 lines of dipole-dipole surveys were conducted. Interpretations of these data show that mean resistivity values become lower and thicknesses of contaminated layers by leachate thicker than those of the previous year in and around the landfill. Especially, mean thicknesses of saturated layers with leachate increased by about 3∼6 m and resistivities of bedrock decreased. Considering actual hydraulic conductivity, such increments of mean thicknesses are somewhat large. But resistivity variations in and around the Nanjido landfill clearly indicates contamination of layers by leachate is in progress even though some errors in measurements and interpretations are considered. On the other hand, sounding data in the back area of the landfill are almost identical to those of the previous year. From these results, it appears that contamination of weathered zone and bed rock is in progress mainly inside and in the front area of the landfill.

• Journal of the Korean Society of Groundwater Environment
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• v.2 no.2
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• pp.64-71
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• 1995

Electrical soundings were conducted in and around the Nanjido waste landfill in August, 1994 and February, 1995. Schlumberger array was adopted and 37 and 22 soundings were performed around and in the Nanjido landfill, respectively. Besides, self potentials were measured at 50 points, in front of the right Nanjido landfill. Interpretations of the sounding data show low resistivity zones of about 10 Ω-m at depth ranging from 10 to 80 m from the surface in front of the landfill and of about 6 Ω-m at depth ranging from 37 m to 130 m in the landfill. It appears that these low resistivity zones are contaminated by or saturated with leachate, and their depths are deeper than those of boring data by 20∼30 m. These results indicate the possibility of contamination of weathered zone and the upper part of the bed rock in these areas. But sounding data obtained at the back of the landfill reveal more resistive and thinner low resistivity zones than those in and in front of the landfill. Thus it is concluded that the degree of contamination by leachate in and in front of the landfill is greater than that at the back of the landfill.

• Journal of the Korean Society of Groundwater Environment
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• v.3 no.2
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• pp.51-59
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• 1996

In case waste disposal site is to be constructed close to the underground facilities such as LPG storage cavern which is completely maintained by groundwater pressure, it is generally requested that the possibility on leachate contamination of cavern area be reviewed and the countermeasure, if it is estimated cavern area is severely affected by leachate, be taken into consideration. Prediction was performed and leachate control plan was made using by analytical and the numerical analysis on the leachate migration which is likely to happen at the area between the proposed waste disposal site and the underground LPG storage cavern located at the U petrochemical complex. Analytical solutions were obtained by the conservative mass advection-diffusion equation and the effect of advection and dispersion factor on the leachate migration was reviewed through peclet number calculation and the functional relationship between the factors and leachate transport velocity was established, which leads to enable us to predict the leachate transport velocity without difficulties when different parameters (factors) are used for analytical solution. Numerical solutions were obtained by FEM using AQUA2D which is for the simulation of groundwater flow and contaminant transport. 3-D discrete fracture models were simulated and fracture flow analysis was performed and feasibility study on the water-curtain system was conducted through the fracture connectivity analysis in rock mass. As results of those analyses, it was interpreted that the leachate would trespass on the LPG storage cavern area in 30 years from the proposed wate disposal site and the vertical water-curtain system was effective mathod for the prevention of leachate's migration further into the cavern area.

• Journal of Animal Environmental Science
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• v.1 no.2
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• pp.173-178
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• 1995

The aim of this study was to describe the NO$_3$ leaching in grassland ecosy-stems. Field study was performed in the southwestern district of Germany from 1991 to 1993. The study included 3 different slurry application, conventional slurry application, 50% reduced slurry application and without slurry application. On each plot were installed 3 ceramic cups at 120cm depth. Samples were collected twice a month and analysed for NO$_3$ colorimetrically using a Tecator Auto-Analyzer. Percolation was calculated as the difference between precipitation and potential evapotranspiration. The NO$_3$ concentration in soil water was remarkably variable during the year. The average NO$_3$ concentration during the experiment was the lowest (8.5mg/l) without slurry application and the highest with 240kg N/ha cattle slurry (25.3mg/l). the NO$_3$-N leached per year were respectively 29, 23, and 12kg/ha in case of 240, 120 and 0kg N/ha when cattle slurry was applied. The conventional feeding density of cattle husbandry in the district caused the NO$_3$ contamination in ground water. When the amount of cattle slurry applied was reduced to 50%, the NO$_3$ loading in ground water was reduced greatly. Therefore, the reduction policy of cattle slurry can positively contribute to the prevention of the NO$_3$-contamination in groundwater.

• Economic and Environmental Geology
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• v.41 no.6
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• pp.709-717
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• 2008

Rhizofiltration for cesium uptake by sunflowers (Helianthus annuus L.) and beans (Phaseolus vulgaris var.) was investigated for groundwater contamination. The cesium removal by sunflowers was greater than 98% of the total cesium in solution, and the uptake by beans was also greater than 99% within 24 hours of the rhizofiltration, showing that the rhizofiltration has a great capability to remove cesium from the contaminated water system. Experiments at various pH of solution indicated that a solution of pH $5{\sim}9$ yielded very high cesium accumulation in two plants. From the results of the analysis for cesium accumulation in plant parts, about 80% of cesium transferred into the plant from solution was accumulated in the root part and less than 20% of cesium existed in the shoot part (including leaves). Results suggest that only the roots of the fully grown plant used for rhizofiltration should be disposed or post-treated and thus the cost and time to treat massive amounts of grown plants could be dramatically reduced when sunflower and bean are used in the real field. The results of SEM and EDS analyses indicated that the most of cesium were accumulated in the root surface as a ionic phase rather than a soil precipitation phase.

• Journal of Food Hygiene and Safety
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• v.28 no.4
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• pp.312-318
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• 2013

This study validated microbiological hazards of ginseng farms at the cultivation stage and suggested recommendations to develop a good agricultural practices (GAP) model. A total of 96 samples were collected from cultivation environments (soil, irrigation water, and atmosphere), plants (ginseng and its leaf), personnel hygiene (glove, cloth, and hand) of 3 ginseng farms (A, B, and C) and were tested to analyze sanitary indicator bacteria (aerobic plate count, coliforms and Escherichia coli), major foodborne pathogens (E. coli O157:H7, Listeria monocytogenes, Salmonella spp., Staphylococcus aureus, and Bacillus cereus), and fungi. Total bacteria, coliform, and fungi in the 3 ginseng farms were detected at the level of 1.3~6.0, 0.1~5.0, and 0.4~4.9 v/g (or mL, hand, and $100cm^2$), respectively. Only irrigation water collected from one ginseng farm was confirmed to be E. coli positive. In case of pathogenic bacteria, B. cereus was detected at levels of 0.1~5.0 log CFU/g (or mL, hand, and $100cm^2$) in all samples, but other pathogen bacterias were not detected in any samples from all farms. Although E. coli were detected in irrigation water, the level of microbial for the three farms was lower than the regulation limit. According to the results, the ginsengs produced from the 3 farms were comparatively safe with respect to microbiological hazard. However, cross-contamination of bacteria from environments and workers to ginseng has been considered as potential risks. Therefore, to minimize microbial contamination in ginseng, GAP model should be applied for ensuring the safety of ginsengs.

• Journal of Korean Society of Forest Science
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• v.86 no.4
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• pp.435-442
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• 1997

The research was carried out to investigate the contamination of stream water by the acid mine drainage originated from the abandoned coal mines and coal waste rock in Keumsan, Chungnam. The pH, sulfate and chemical compositions in the stream water were analyzed. At the polluted sites, the pH of stream water was the strong acid, ranging from 3.46 to 4.29. The pH shows negative correlations with sulfate, manganese, copper, zinc, iron and magnesium concentrations. Sulfate concentrations of the polluted stream water, 236.73-310.53mg/l, had 10 times more than those of the non-polluted stream water. The concentrations of heavy metals, Mn and Fe, in the polluted water were 0.56 - 0.83mg/l and 5.89 - 10.58mg/l, respectively. The Mn concentrations were 20 times higher than those of the non-polluted stream water. Compared with those in the non-polluted stream water, the Mg and Ca concentrations in the polluted stream water were high because of leaching from rock and soil to water by the acidifications. Calculated AMDI(Acid Mine Drainage Index) values are low in the polluted stream water, relative to those of the non-polluted water.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.769-772
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• 2008

The problem of disposing construction waste materials has become a national and social problem. Recycled powder generated in the process of making aggregate, and the recycled powder is land-filled in its entirety. Results of toxicity testing of recycled power show that it contains base-pair substituent mutagenicity. As recycled powder is disposed of as landfill, it can cause secondary contamination such as soil and underground water contamination. There has been very little research made on recycled powder. This study has examined the utilization of concrete mixture by using recycled powder in a mixture instead of cement and compared and analyzed the characteristics of dynamics and workability. This study has examined the application of recycled powder in concrete. Depending on the replacement rate and workability, test piece was manufactured using different mixing rate by CP, WCP, PCP. The CP was used to examine the physical property of concrete and characteristics its dynamics. The letters W of WCP and P of PCP are the initials of water and mixture. They were made using the standard mixing ratiosemphasizing the workability to determine the characteristic of dynamics of concrete based on the mixing ratio of recycled powder. With the increase in the replacement rate, CP had very little change in the strength. But with the decline of slump, the workability was not good. The result of manufacturing WCP and PCP using the standard mixing ratio showed that WCP had a drop in strength compared to the plain. PCP had almost the same value as the plain only when the replacement rate was 10%. When it was higher than that, a reduction in strength was observed.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.321-327
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• 2005

Staphylococcus aureus is spread worldwide and can result in food poisoning outbreaks. Among samples collected from soil, water, protected houses, packing houses, employees, strawberries, and leaves, and analyzed for S. aureus contamination, 16% samples 'showed S. aureus contamination, particularly on employees' hands, scissors, and strawberries. Examination of enterotoxins A, B, and C genes of S. aureus by PCR revealed sea and seb in 92 and 38% of total strains, respectively, whereas sec was not detected. In conclusion, implementation of Good Agricultural Practice is necessary for preventing food-borne diseases of staphylococcal origin, thereby ensuring the safety of farm-to-table products.