• Korean Journal of Environmental Agriculture
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• v.33 no.3
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• pp.155-163
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• 2014

BACKGROUND: Recent studies for heavy metal stabilization in soil were mainly focused on finding out new materials and its efficiency. But, such a stabilization method can cause disturbance to soil, leading improper environment for agriculture. The object of this study was to demonstrate the effect of the incorporation of green manure crops on heavy metal-contaminated soil. METHODS AND RESULTS: Soil contaminated with heavy metals was collected from the agricultural soils affected by the abandoned mine. Lime stone was selected and treated to contaminated soil. Three kinds of legume green manure crops; Alfalfa (Medicago sativa), Hairy vetch (Vicia villosa), Red clover (Trifolium pratense) were subsequently cultivated in greenhouse condition. It was found that lime stone increased soil pH and decreased the amount of heavy metal absorption by green manure. The application of green manure residues on soil increased soil pH and inorganic nitrogen. CONCLUSION: The C/N ratio of three green manures was low, indicating fast decomposition rate, resulting in nitrogen supplement, consequently. Considering the point that the soil was used for agricultural purpose, it was recommended that hairy vetch and red clover were preferred. Nevertheless, the heavy metal availability was also increased. Thus, it seemed that further study was needed to confirm that how long maintain a phenomenon.

• Journal of Korean Society on Water Environment
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• v.30 no.4
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• pp.403-408
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• 2014

The toxicity of heavy metals (Zn, Pb) and diesel, in single and binary solution was investigated using the photobacterium Vibrio fischeri (Microtox test) as a test organism. In this experiment, the concentration of water soluble fraction of diesel was based on the total petroleum hydrocarbon (TPH). The toxicity of each single compound showed the following $EC_{50}$ (15min): Zn 1.90 mg/L, Pb 0.31 mg/L, TPH 2.09 mg/L. The observed toxicity of binary mixtures increased, depending on the concentration of the mixed substance. The effects were defined as synergistic, antagonistic, or additive, in accordance with the sign of difference between the predicted and observed toxicity at binary mixtures. The interactive effects between zinc and lead were synergistic, on the other hand, antagonistic and additive effects were found in each metal and TPH mixtures on the bioluminescence of V. fischeri.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 1995.05a
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• pp.8-9
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• 1995

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.519-524
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• 2005

This study was carried out to survey the contents of mineral and heavy metal of the commercial salt and salted-fermented shrimp. Mineral and heavy metal contents of Korean products and imported salts, and their effects on shrimps were analyzed through ICP-AES/MS. K and Mg contents of Korean salts and salted-fermented shrimp were relatively higher than those imported ones, However, no significant differences were found for mineral of commercial salted-fermented shrimps between Korean products and imported ones. Heavy metal contents of commercial salts lower than the maximum permissible limit set by KFDA. As, HB, and Ni were not detected in both commercial and lab-made salted-fermented shrimps. Cd were detected ranges of ND-0.5 ppm (average 0.1ppm) for commercial salted-fermented shrimps. Pb were detected ranges of ND-0.8ppm(average 0.28ppm) for lab-made salted-fermented shrimps.

• Journal of the Korean Geosynthetics Society
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• v.13 no.1
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• pp.63-70
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• 2014

This paper describes the influence of rainfall on contamination at stream around the developed quarry. The investigation results are analyzed to evaluate the relationship rainfall and heavy metals (or water pollution). In the relationship rainfall and heavy metals, the result showed that the heavy metal contaminations are caused by boulder stone, waste residue and stone sludge, which is reacted with the direct contamination source, in the burried layer. It also found that the water flow change of stream according to the rainfall increase affected the large effect to a contamination level of heavy metal. the water pollution was increased by time changed from the rainy season to the dry season. That is, a lot of suspended solids had been discharge from the developed quarry due to rainfall increase, and then pollution level of water increases as the undercurrent of suspended solids is generated in stream due to rainfall decrease. Therefore, it analyzed that continuous causes of heavy metal contamination and water pollution in stream are materials in the burried layer and a discharge of pollution source from the developed quarry due to rainfall.

• Journal of the Korean Society of Tobacco Science
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• v.20 no.1
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• pp.5-12
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• 1998

Pot experiment was conducted to investigate the effects of fly ash on growth responses and on accumulation of the heavy metals in soil. Two kinds of fly ash, anthracite and bituminous coal, were treated with different levels of 0, 0.4, 0.8, and 1.2 kg/pot(20L). Tobacco growth was better by application of fly ash than that by the control. However, the early stage of growth by application of bituminous coal, 1.2 kg/pot, was decreased due to the boron toxicity occurred by fly ash. Generally, tobacco yield was significantly increased with applying fly ash, showing the highest yield at 1.2 kg/pot for anthracite and at 0.8 kg/pot for bituminous coal. The content of total nitrogen in leaves was higher with fly ash than that of the control, while the content of calcium in leaves was low, Contents of heavy metal and the other minerals were not significantly different between the control and the treatment of fly ash. Soil pH after experiment was linearly increased with application level of fly ash, indicating that the application of bituminous coal was more effective than that of anthracite. Contents of available phosphate, exchangeable $Ca^{2+}$+ and $Mg^{2+}$ in soil were increased by application of fly ash, especially with bituminous coal. Contents of Cu, Cr, and Ni were increased with application level of bituminous coati even if the contents were still lower than critical levels for farming land. The other heavy metals were similar between the control and the application of fly ash.

• Proceedings of the Korean Magnestics Society Conference
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• 2016.05a
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• pp.61-61
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• 2016

• Journal of the korean society of oceanography
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• v.37 no.4
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• pp.232-241
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• 2002

The potential role of environmental factors on extractable lipofuscin accumulation rate in the blue crab was studied by examining the effect of temperature on laboratory reared blue crabs and the effect of trace metals from samples collected at impacted sites (Baltimore Harbor) and a relatively pristine site (outdoor ponds at Horn Point Laboratory, Cambridge, MD, USA). Lipofuscin levels did not significantly related with sampling sites or heavy metal concentrations in the crab tissue. Heavy metal body burden was highly variable among sampling sites and tissue types but significantly higher for both impacted areas (Curtis Creek and Inner Harbor) in comparison to the reference site. Among tissue types, gills showed the highest metal concentrations with the exception of Hg, which was highest in muscle tissue. For two groups of crabs that were held at either ambient (4 to 1$0^{\circ}C$) or heated seawater (19$^{\circ}C$) for two months, normalized-lipofuscin levels were significantly different (P-0.001). Results suggest that temperature may affect lipofuscin accumulation (=0.25ng-lipofuscin/mg-protein/temperature-degree day). Therefore, temperature should be considered for accurate age calibration of crab populations using lipofuscin.

• The Korean Journal of Ecology
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• v.21 no.3
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• pp.179-186
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• 1998

Effects of lead(Pb) and calcium(Ca) on growth responses, accumulation of heavy metals and nitrogen fixation activities of Melilotus suaveolens seedlings were quantitatively analyzed during growing period. Pb contents of the root treated with 30, 100 ppm Pb and 100 ppm Pb added 100 ppm Ca were 54.1, 90.9 and 26.1 folds higher than that of the control, respectively, at pH 4.2 in 28th days, and heavy metal content of plant increased with increasing of pH and Pb concentration. The melilot plant was classified as a Pb accumulator by higher accumulation of Pb in shoot than that of root. Pb treatments resulted in inhibiton of height and chlorophyll contet, and Ca treatment increased height and chlorophyll content insignificantly at pH 4.2 in 28 days. The plant biomass reduced 49, 60 and 54% at pH 4.2 and 47,53 and 50% at pH 6.5, respectively, by 30, 100 ppm Pb and 100 ppm Pb added 100 ppm Ca treatment. Specific nitrogen fixation of nodules reduced 68.4% and 46.6% by 100 ppm Pb treatment and 3.7% and 24.9% by 100 ppm Pb added 100 ppm Ca at pH 4.2 and pH 6.5, respectively, so Ca inhibited significantly Pb activity and toxicity in acdic pH. Nodule formation were reduced to 33, 33 and 50% at pH 4.2 and 50, 33 and 38% at pH 6.5 by 30, 100 ppm Pb and 100 ppm Pb added 100 ppm Ca, respectively.

• Journal of Powder Materials
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• v.26 no.3
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• pp.201-207
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• 2019

Tungsten heavy alloys (W-Ni-Fe) play an important role in various industries because of their excellent mechanical properties, such as the excellent hardness of tungsten, low thermal expansion, corrosion resistance of nickel, and ductility of iron. In tungsten heavy alloys, tungsten nanoparticles allow the relatively low-temperature molding of high-melting-point tungsten and can improve densification. In this study, to improve the densification of tungsten heavy alloy, nanoparticles are manufactured by ultrasonic milling of metal oxide. The physical properties of the metal oxide and the solvent viscosity are selected as the main parameters. When the density is low and the Mohs hardness is high, the particle size distribution is relatively high. When the density is high and the Mohs hardness is low, the particle size distribution is relatively low. Additionally, the average particle size tends to decrease with increasing viscosity. Metal oxides prepared by ultrasonic milling in high-viscosity solvent show an average particle size of less than 300 nm based on the dynamic light scattering and scanning electron microscopy analysis. The effects of the physical properties of the metal oxide and the solvent viscosity on the pulverization are analyzed experimentally.