• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.6
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• pp.88-94
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• 2013

The hexavalent chromium (Cr(VI)) is well known as a hazardous ion, presumably inducing dermatic diseases and if serious cancer. The present study concerns the binding capacity of Cr(VI) ions in the cement powder and matrix for a quantitative technique of Cr(VI) ions in cement to influence human health. Both the water-soluble and acid-soluble Cr(VI) ions present in 3 types of ordinary Portland cement (OPC), pulverised fuel ash (PFA), ground granulated blast furnace slag (GGBS), and silica fume (SF) were measured using the spectrophotometer. As a result, it was found that the concentration of water-soluble Cr(VI) ion in cement ranged from 10.5 to 18.9mg/kg-cement, and in the additional materials a very low value of Cr(VI) ion was measured. Acid-soluble Cr(VI) ion was even higher than water-soluble Cr(VI) ion, ranging from 172.4 to 318.2mg/kg-cement. Nevertheless, the concentration of acid-soluble Cr(VI) ion is not proportional to addition of acid. It depends rather the variable pH of solvent involving cement paste. As enough cement hydration occurs, the binding capacity of Cr(VI) ion increases, inhibiting this ions from leaching out in the presence of hydration products such as ettringite or tri-calcium aluminate which bind Cr(VI) ion by ion-exchange.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.1
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• pp.9-16
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• 2001

Chromium exposure can be in the forms of environmental pollution and occupational exposure. The harmful effects of chromium on the body greatly differ depending on its valence or solubility. Accordingly, the recommended permissible exposure limit for each chromium compound is different. This study investigated the increase or decrease of distribution and excretion of total chromium exposed simultaneously the soluble Cr+6 and Cr+3 compounds. There were no difference of total chromium concentration in plasma, red bloods cells, urine, organs between simultaneously injected and individually injected soluble Cr+6 and Cr+3 compound. The chromium clearances in urine also showed that there were two phases in the two groups. In the first phase, biological half lives of the total chromium of the two groups have been similar within 24 hr., but in the second phase, biological half life of the group injected simultaneously was 62.7 hr. and was less than that of the other group's 188.3 hr. The average concentration of total chromium in plasma was same with the control, and that of RBCs was $0.218nmol/m{\ell}$ and was slightly increased in comparison with $0.121nmol/m{\ell}$ of the control, which was not statistically significant. As a result, there were no differences of distribution and excretion of chromium between the group exposed simultaneously and the other group exposed separately the soluble Cr+6 and Cr+3 compounds. The biological half life of chromium of the former group in urine was less than that of the other group.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.242-246
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• 2006

Background level of heavy metals In soils (316 points by 15 classifications of land use) was investigated by two test methods, 0.1N HCl(1N HCl for As) extraction and aqua regia extraction methods. The average concentrations of aqua regia extractable heavy metals in soil(n=316) was 6.24(As), 0.25(Cd), 37.99(Cr), 24.10(Cu), 0.04(Hg), 25.68(Pb), 22.59(Ni), 106.11(Zn) mg/kg, respectively. Also the average concentrations of 0.1N HCl extractable heavy metals was 0.06(As), 0.08(Cd), 0.27(Cr), 3.78(Cu), 4.02(Pb), 12.5(Zn), 0.58(Ni) mg/kg, respectively. The ratio of soluble contents and total contents were 2.6%(As), 32.7%(Cd), 0.7%(Cr), 15.7%(Cu), 15.7%(Pb), 2.6%(Ni), 11.8%(Zn), and the correlation coefficient of soluble contents and total contents were 0.26(As), 0.27(Cd), 0.22(Cr), 0.57(Cu), 0.42(Pb), 0.23(Ni), 0.72(Zn).

• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.855-862
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• 2006

Hexavalent chromium ($Cr^{6+}$) is a highly harmful pollutant, which can be detoxified and precipitated through reduction to $Cr^{3+}$. Bacillus megaterium TKW3 previously isolated from chromium-contaminated marine sediments was capable of reducing $Cr^{6+}$ in concomitance with metalloids ($Se^{4+}$, $Se^{6+}$, and $As^{5+}$). Notwithstanding approximately 50% inhibition, it was the first report of simultaneous bacterial reduction of $Cr^{6+}$ and $Se^{4+}$ (to elemental Se). No significant difference was observed among electron donors (glucose, maltose, and mannitol) on $Cr^{6+}$ reduction by B. megaterium TKW3. The reduction was constitutive and determined to be non-plasmid mediated. Peptide mass fingerprints (PMF) revealed a novel aerobic membrane-associated reductase with $Cr^{6+}$-induced expression and specific reductive activity (in nmol $Cr^{6+}$/mg protein/min) of 0.220 as compared with 0.087 of the soluble protein fraction. Respiratory inhibitor $NaN_3$ did not interfere with the reductase activity. Transmission electron microscopy with energy dispersive X-ray (TEM-EDX) analysis confirmed the aggregation of reduced chromium along the intracellular membrane region. Future identification of the N-terminal amino acid sequence of this reductase will facilitate purification and understanding of its enzymatic action.

• Journal of Environmental Health Sciences
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• v.29 no.4
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• pp.42-47
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• 2003

The purpose of this experimental study is to investigate seasonal deposition flux variations of the total dustfall and various inorganic elements in it. Total of 84 dustfall samples were collected from September, 1997 thru August, 1998 at 7 different sites in Kunsan. Each sample was analyzed by an AAS to determine the levels of 5 inorganic elements; Zn, Cd, Cr, Fe and Pb. Deposition fluxes, soluble/total fractions for each element were extensively investigated. Estimated deposition fluxes of dustfall and elements in Kunsan were in the range of 37.5∼45.1 ton/$\textrm{km}^2$/yr for dustfall, 43.5∼81.8 kg/$\textrm{km}^2$/yr for Zn, 6.6∼11.0 kg/$\textrm{km}^2$/yr for Cd, 44.8∼110.0 kg/$\textrm{km}^2$/yr for Cr, 223∼323 kg/$\textrm{km}^2$/yr for Fe, 10.9∼22.3 kg/$\textrm{km}^2$/yr for Pb, respectively. Thus, the estimated average total deposition fluxes of dustfall in Kunsan(376.35 $\textrm{km}^2$) per day were 43.3 ton and 58.6 kg for Zn, 8.9 kg for Cd, 80.6 kg for Cr, 293.8 kg for Fe and 14.1 kg for Pb, respectively.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.3
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• pp.291-303
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• 1999

The purpose of this experimental study is to investigate seasonal deposition flux variations of the total dustfall and various inorganic elements in it. Total of 84 dustfall samples were collected from September, 1997 thur August, 1998 at 7 different sites in Kunsan. Each sample was analyzed by an AAS to determine the levels of 5 inorganic elements Zn, Cd, Cr, Fe and Pb. Deposition fluxes, soluble/total fractions for each element were extensively investigated. Estimated depositon fluxes of dustfall and elements in Kunsan were in the range of 37.5~45.1 ton/$ extrm{km}^2$/yr for dustfall, 43.5~81.8kg/$\textrm{km}^2$/yr for Zn, 6.6~11.0kg/$\textrm{km}^2$/yr for Cd, 44.8~110.0kg/$\textrm{km}^2$/yr for Cr, 223~323 kg/$\textrm{km}^2$/yr for Fe, 10.9~22.3 kg/$\textrm{km}^2$/yr for Pb, respectively. Thus, the estimated average total deposition fluxes of dustfall in Kunsan(376.35$\textrm{km}^2$) per day were 43.3 ton and 58.6 kg for Zn, 8.9 kg for Cd, 80.6 kg for Cr, 293.8 kg for Fe and 14.1 kg for Pb, respectively.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.521-524
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• 2008

The purpose of this study is to identify the character and condition of Cr in the clinker and thereby contribute to the research for reduction in utilizing Cr in the cement manufacturing process. The concentration of chromium by cement particle size and the distribution of chromium by clinker mineral were measured. Next, correlation was considered between chromium and the soluble components in cement. As a result, in the range that cement particles were 20${\mu}$m or less, highest soluble hexavalent chromium was found. When the concentration of chromium was measured through mineral separation, belite and the interstitial phase were higher in chromium than in alite. soluble hexavalent chromium was contained in domestic cement less than 20ppm, and its conversion ratio was somewhat high as 10 to 40% or so.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.6
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• pp.446-452
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• 2000

This study was carried out to investigate the effect of mine activity on paddy fields, agricultural water, and plants in the ruined Oksung Cu-Zn mine area. Soil samples collected from paddy fields adjacent to the Cu-Zn mine sites were sequentially extracted and determined the contents of heavy metals such as Cd, Zn, Cu, Pb, Cr and Ni. Distribution of exchangeable heavy metals in soils was 30.2% of Cd, 11.3% of Zn, 2.2% of Cu, 4.6% of Cr, 0.6% of Pb and 3.9% of Ni. Water soluble heavy metals were only detected with Zn. The contents of heavy metals in water collected from the mine were 0.01 of Cd, 27.35 of Zn, 4.86 of Cu, 1.04 of Pb, 0.03 of Cr and $0.08mg\;L^{-1}$ of Ni. while the contents in waler collected out of the mine were 16.67 of Zn, 0.59 of Cu, 0.49 of Pb, 0.05 of Cr and $0.06mg\;L^{-1}$ of Ni. On the other hand, agricultural water near mine area were 1.26 of Zn, 0.05 of Cu, 0.05 of Pb and $0.02mg\;L^{-1}$ of Ni. Both Cd and Cr were not detected in the agricultural water.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.5
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• pp.431-443
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• 2000

The purpose of this experimental study is to investigate seasonal deposition flux variations and deposition velocities of the total dusfall and various inorganic elements in it. Total 41 dustfall and TSP samples were collected from November, 1997 through December, 1998 in Kunsan. Each sample was analyzed by and AAS to determine he levels of 5 inorganic elements: Zn, Cd, Cr, Fe and Pb. Deposition fluxes, soluble/total fractions and deposition velocities for each element were extensively investigated. Estimated dry deposition fluxes of dustfall and elements in Kunsan were in the range of 14.6~48.8(mean 25.6) ton/$\textrm{km}^2$/yr for dustfall, 14.5~72.6(mean 44.1)kg/$\textrm{km}^2$/yr for Zn, 0.9~0.5(mean 3.0) kg/$\textrm{km}^2$/yr for Cd, 2.1~239.2(mean 63.9) kg/$\textrm{km}^2$/yr for Cr, 331.6~1,082.7(mean 873.9) kg/$\textrm{km}^2$/yr for Fe, 5.2~178.4(mean 49.2) kg/$\textrm{km}^2$/yr for Pb, respectively. And the concentra-tion of TSP and elements in Kunsan were 71$\mu\textrm{g}/m^3$ for TSP, $29.9ng/m^3$ for Zn, $0.6ng/m^3$ for Cd, $0.1 ng/m^3$ for Cr, $1,061.0 ng/m^3$ for Fe, $4.0 ng/m^3$ for Pb, respectively. And the estimated deposition velocity of dustfall and elements in Kunsan were 1.13$\times$ 10(sup)-2 cm/sec for dustfall, 4.67$\times$ 10(sup)-2 cm/sec for Zn, 16.92 cm/sec for Cd, 15.69 cm/sec for Cr, 1.72$\times$ 10(sup)-2 cm/sec for Fe, 0.36 cm/sec for Pb, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.525-532
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• 2014

Since mine wastes were merely dumped in the mine waste dump, they have produced acid mine drainage (AMD). Therefore, main objective of this study was to evaluate the effect of coal combustion products (CCPs) on heavy metal stabilization and detoxification for mine wastes. Total six treatments for incubation test were conducted depending on mixing method (completely mixing and layered). Also, lysimeter experiment was conducted to examine efficiency of polyacrylamide (PAM) on reduction of mine wastes erosion. Result of incubation test showed that concentrations of soluble aluminium (Al) and iron (Fe) in leachate decreased compared to control. The lowest soluble Al and Fe in leachate was observed in 50% mixed treatment (14.2 and $1.03mg\;kg^{-1}$ for Al and Fe respectively) compared to control treatment (253.0 for Al and $52.6mg\;kg^{-1}$ for Fe). The pH of mine wastes (MW) and leachate increased compared to control after mixing with CCPs and ordered as control (MW 6.4, leachate 6.3) < 10% (MW 7.7, leachate 7.1) < 20% (MW 9.0, leachate 7.8) < 30% (MW 9.5, leachate 8.3) < 40% (MW 9.9, leachate 8.5) < 50% (MW 10.5, leachate 8.6). Application of PAM, both in liquid and granular type, dramatically decreased the suspended solid (SS) concentration of CCPs treatments. Reduction of SS loss was ordered as MW70CR30L ($24.4mg\;L^{-1}$) > MW70CR30LPL ($6.7mg\;L^{-1}$) > NT ($3.1mg\;L^{-1}$) > MW70CR30M ($1.6mg\;L^{-1}$) > MW70CR30MPL ($1.1mg\;L^{-1}$) > MW70CR30PGM ($0.7mg\;L^{-1}$) > MW70CR30LPG ($0.5mg\;L^{-1}$) > MW70CR30MPG ($0.4mg\;L^{-1}$). Overall, application of CCPs can be environmental friendly and cost-effective way to remediate coal mine wastes contaminated with heavy metals. In addition, use of PAM could help to prevent the erosion coal mine wastes in mine waste disposal area.