• Korean Journal of Microbiology
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• v.38 no.1
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• pp.26-30
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• 2002

A ubiquitous bacterium,Effects of Lead, Copper and Cadmium on Pseudomonas cepacia KH410 Isolated from Freshwater Plant Root was isolated from freshwater plant root and interactions of lead, copper and cadmium with this strain was studied. Mass production of dry cell weight 2.72 g-DCW/ι-medium was obtained by cultivation in a nutrient medium containing 1% yeast extract, 1% soytone and 0.5% NaCl, pH 7.0, at temperature of 28℃ for 24 hrs under aeration. The mass of dry cell produced after exposure with 100 mg/ι of heavy metal was 1.98 g/ι for lead, 1.58 g/ι for copper and 0.20 g/ι for cadmium, respectively. The minimal inhibitory concentrations (MIC) for each heavy metal was 1.3 mM for lead,0.8 mM for copper and 0.4 mM fur cadmium, respectively. Cell aggregation occurred by each heavy metal exposure was observed from 1 day to 4 days by an optical microscope. Entrapment, precipitation effects on cell by heavy metals between 10 min and two hours were examined by an electron microscopy. Cadmium appeared to be the most toxic on cells and the order of toxicity was cadmium>copper>lead.

• Clean Technology
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• v.17 no.2
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• pp.150-155
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• 2011

The removal process of heavy metal ion in aqueous solution by the functionalized silica bead was simulated using the finite difference method. Equilibrium model and non-equilibrium model were proposed and the effects of dimensionless groups and various parameters were investigated. Freundlich isotherm was used in equilibrium model and 1st order adsorption rate expression was assumed in non-equilibrium model. The comparison results by the predictions of equilibrium and non-equilibrium models showed good agreement. The predictions of equilibrium model were compared with experimental results reported in literature and showed the marginal agreement.

• Journal of the Korean Ceramic Society
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• v.40 no.8
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• pp.725-729
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• 2003

The fluorine doping along with heavy metal oxides remarkably raised the $^3$H$_4$ lifetime and the quantum efficiency in Tm$^{3+}$-doped silicate glasses. 29 mol% of fluorine substitution for oxygen in 70SiO$_2$-15Pbo-12ZnO-3KO$_{1}$2/ glass raised $^3$H$_4$ lifetime to 193 $mutextrm{s}$. Refractive indices were raised by heavy metal oxide substitution, but hardly changed by fluorine substitution. The fluorine doping changed the local structure around Tm$^{3+}$ions, then low energy vibrations related to fluorine are considered to largely reduce the multi-phonon relaxation rates in the oxyfluoride silicate glasses. The $^3$H$_4$ lifetimes and absorption and emission spectra of Tm$^{3+}$doped silicate and oxyfluoride silicate glasses are reported, and Judd-Ofelt calculation results are discussed in this paper.

• The Plant Pathology Journal
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• v.28 no.4
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• pp.446-452
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• 2012

The effect of heavy metals on seedling growth and pigment levels was studied in Arabidopsis using essential (Cu, Mn, and Zn) and non-essential metals (Pb and Hg). Generally increasing the concentrations of the metals resulted in a gradual decrease in root and shoot lengths, a decrease in chlorophylls, an increase in anthocyanins and a fluctuation in carotenoid content depending on the metal types. The toxicity of the metals decreased in the following order: Cu > Hg > Pb > Zn > Mn. Among the five metals, Cu was exceptionally toxic and the most potent inducer of anthocyanins. Pb induced the smallest quantity of anthocyanins but it was the strongest inducer of carotenoids. It suggests that the Cu-stressed Arabidopsis may use anthocyanins as its main antioxidants while the Pb-stressed Arabidopsis use carotenoids as its main protectants. All of the five metals induced an accumulation of anthocyanins. The consistent increase in anthocyanin content in the metal-stressed Arabidpsis indicates that anthocyanins play a major role in the protection against metal stresses.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.149-155
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• 2003

Objectives of this research were to fractionate heavy metals in soil samples in the upper Okdong River basin and to assess the potential pollution index of each metal fraction. Soil samples were collected from cultivated land soils and analyzed for physical and chemical properties. pH of cultivated soils ranged from 5.2 to 7.6. Contents of total kelhaldal nitrogen and loss on ignition were in the ranges of 0.6∼2.5%, and 1.9∼12.9%, respectively. Heavy metals in the cultivated land soils were higher in the abandoned closed coal mine near field soils than those in the paddy soils. Total concentrations of metals in the cultivated land soils were in the orders of Zn > Pb > Ni > Cu > Cd, exceed the corrective action level of the Soil Environment Conservation Law and higher than the naturals were abundance levels reported from uncontaminated cultivated land soils. Mobile fractions of metals were relatively small compared to the total concentrations. Soil Pollution Assesment Index(SPAI) values of each fraction of metals were leveled from Non polluted to Moderately polluted based on total concentrations. SPAI values of mobil fractions were lower than those of immobile fractions. Results on metal fractions and SPAI values of the cultivated land soils indicate that field soils samples were contaminated with heavy metals and had potential to cause a detrimental effects on plants. A prompt countermeasure to prevent field soils in the abandoned closed coal mine near fields are urgently needed.

• Korean Journal of Environmental Agriculture
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• v.17 no.2
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• pp.150-155
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• 1998

To investigate effects of organic matter application on heavy metal uptake of infant rice seeding, the various amount of organic matter(peat and $Bio-com^{(R)}$)was applied on Cd or Cu treated nursery bed soil. No growth difference was observed up to 20mg/kg of Cu treatment. Above 20mg/kg of Cu treatment, the seeding height and top dry weight were decreased but the Cu uptake by seeding was increased with increasing Cu treatment level. The mat formation was poor above 20mg/kg of Cu treatment, however, the seeding peat application level. All peat treatment resulted better mat formation than control. The seeding height and top dry increasing Cd treatment level. The mat formation was not effected by either Cd treatment level or organic matter sources. The effect of peat and $Bio-com{(R)}$ application on Cd uptake by infant rice seeding was not observed at all Cd treatments level.

• Journal of Korea Society of Waste Management
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• v.35 no.8
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• pp.721-730
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• 2018

We investigated the effects of heavy metals in cement in the last 3 years and the amount of waste in the cement manufacturing process. The result shows that the average $Cr^{6+}$ content in cement products is controlled at 10 mg/kg. Cu and Pb have lower detection tendency in white cement than in ordinary portland cement. In addition, heavy metals such as Cd show a certain level of detection regardless of the input wastes. Copper slag and phosphate gypsum are the main influencing factors on the heavy metals in cement products. In auxiliary fuels, plastics waste and wood waste are considered to affect heavy metals in cement products. Alternative raw materials are considered to be affected by the alternative raw materials managed as byproducts. In the case of supplementary fuels, auxiliary fuels managed as waste instead of auxiliary fuels managed as byproducts affect the heavy metals in cement. This study examined the input amount without considering the heavy metals in each waste. Therefore, the result may vary in different situations, and further research must be conducted to supplement the findings. However, if the heavy-metal contents in the waste are constant, it can be used as a reference material for the control of heavy metals in cement products.

• Journal of Welding and Joining
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• v.29 no.6
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• pp.71-76
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• 2011

Submerged arc welding method from both sides is generally applied to the welding of main panel manufacturing process during ship construction. The tandem SAW method is applied to improve the productivity. The various weld defects that occur during tandem SAW method are melt through, incomplete penetration, undercut and overlap etc. It could be thought that the reasons for these defects are mainly lack of prediction ability for penetration depth and deposited metal area. In this research, total 5 kinds of welding factors for experiment like current of lead pole, voltage of lead pole, current of trail pole, voltage of trail pole and welding speed are adopted. Weld tests are carried out for the analysis of variation effects of these factors on penetration depth and deposited metal area. Based on the test and analysis results, it is possible to obtain the prediction equation for the effect of these factors on the amount of deposited metal and penetration depth. As per the verification of the results by additional tests, it is confirmed that the prediction equation, include a error margin of ${\pm}2mm$ for penetration depth and ${\pm}10mm2$ for deposited metal area.

• Resources Recycling
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• v.19 no.2
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• pp.54-62
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• 2010

In order to obtain the basic data for recycling of coal mine tailings, the characteristics of coal mine tailings, the formation of AMD from the tailings and the leaching of heavy metal from the tailings were studied. The samples were characterized in terms of chemical composition, mineral composition and content of heavy metal of the tailings were investigated. The effects of time, temperature, content of pyrite, sulfide minerals on the formation of AMD were also investigated. For the leaching tests, the KS method, TCLP method and column test were used. From the investigated data, we can see that the coal mine tailings can be used as aggregate for filling used gallery. We can also see that the formation of AMD from coal mine tailings can be prevented by mixing 4% or more limestone with it.

• The Korean Journal of Zoology
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• v.21 no.2
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• pp.43-58
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• 1978

Heavy metal treatment on the fertilized frog eggs before the first cleavage results in a quantitative alteration in the number of PGCs. The formation of PGCs is inhibited by a limited range of heavy metal during the early embryonic development. Total doses of lead above 70ppm and doses of cadmium above 4ppm result in a partial reduction of germ cells at the mitotically dormant stage. After this stage the germ cell number increases almost at the same rate as the untreated control tadpoles. In contrast, on mercury treated eggs, total doses above 0.8ppm cause more damage to germ cell formation. Their proliferation rate thereafter seems to be lower compared with the others. These facts seem to suggest that the heavy metal treatment on frog eggs prior to the first cleavage division is not highly effective in the complete elimination of PGCs in constrast with UV irradiation, even though cytolysis of the tissue occurs in the tadpoles.