• Journal of Soil and Groundwater Environment
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• v.15 no.4
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• pp.39-45
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• 2010

In order to treat paddy soils contaminated by Pb, Cd, and As near the abandoned mine, $H_2PO_4$ was used for stabilization of Pb ($PO_4$/Pb mole ratio of 2/1). In addition, $CaCO_3$ and $FeSO_4$ were used as stabilizers for treating Cd and As (2% w/w), respectively. Leaching tests were conducted with artificial rain in the column to assess the heavy metal stabilization efficiency. The mass of heavy metals in the effluents passed through the columns were analyzed. The remaining heavy metals in the soils were also analyzed as Korean soil standard method, phytoavailability test and sequential extraction test. Lead in the effluent was not detected when $H_2PO_4$ was used as a stabilizer. This result suggests that $H_2PO_4$ is efficient for Pb stabilization. In addition results of sequential extraction scheme suggest that heavy metals are present as residual forms which is not easily extracted.

• The Korea Journal of Herbology
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• v.23 no.4
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• pp.51-58
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• 2008

Objectives: To compare the contents of heavy metals, residual pesticides and sulfur dioxide before/after a decoction. Methods: The heavy metal contents before/after a decoction were measured by Inductively Coupled Plasma Atomic Emission Spectrometer(ICP-AES) and mercury analyzer. In order to analyze pesticides in 5 samples we used simultaneous multi-residue analysis of pesticides by GC/ECD, which was followed by GC/MSD analysis to confirm the identity of the detected pesticide in each sample. In addition, the contents of sulfur dioxide($SO_2$) were performed by Monier-Williams distillation method. Results: 1. The mean values of heavy metal contents(mg/kg) for the samples were as follows: Galgeun-tang(before decoction-Pb; 0.793, Cd; 0.133, As; 0.016 and Hg; 0.005, after decoction-Pb; 0.033, Cd; 0.004, As; 0.002 and Hg; not detected), Gumiganghwal-tang(before decoction-Pb; 0.934, Cd; 0.197, As; 0.046 and Hg; 0.006, after decoction-Pb; 0.062, Cd; 0.007, As; 0.004 and Hg; 0.0001), Sosiho-tang(before decoction-Pb; 0.891, Cd; 0.134, As; 0.091 and Hg; 0.014, after decoction-Pb; 0.036, Cd; 0.002, As; 0.004 and Hg; not detected), Ojuck-san(before decoction-Pb; 0.907, Cd; 0.136, As; 0.084 and Hg; 0.007, after decoction-Pb; 0.074, Cd; 0.007, As; 0.011 and Hg; 0.0005) and Samsoeum(before decoction-Pb; 1.234, Cd; 0.154, As; 0.016 and Hg; 0.007, after decoction-Pb; 0.094, Cd; 0.006, As; 0.002 and Hg; 0.001). 2. Contents(mg/kg) of residual pesticides before/after a decoction in all samples were not detected. 3. Contents(mg/kg) of sulfur dioxide($SO_2$) before a decoction in Galgeun-tang, Gumiganghwal-tang, Sosiho-tang, Ojuck-san and Samsoeum exhibited 1.2, 3.4, 11.1, 12.0 and 5.7, respectively. However, contents of sulfur dioxide after a decoction in all samples were not detected. Conclusions: These results will be used to establish a criterion of heavy metals, residual pesticides and sulfur dioxide.

• Economic and Environmental Geology
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• v.42 no.5
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• pp.427-434
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• 2009

Indigenous bacterium which shows a tolerance to high metal toxicity was isolated from soil concomitantly contaminated with oil and heavy metals. The characteristics of the bacterium for Pb and Cd biosorption was investigated under the various experimental conditions such as bacterial growth phase, the initial metal concentration, the input biomass amount, temperature and pH. The Langmuir adsorption isotherm modeling was described to know the capacity and intensity of biosorption. The low initial concentration of heavy metals and high biomass has a maximum heavy metal removal efficiency, but biosorption capacity of Pb and Cd has different values. Biosorption efficiency was highest in the end of the microbial growth stage and under pH 5~9 condition, but was less affected by temperature variation of 25~$35^{\circ}C$. The maximum biosorption capacity for Pb and Cd was 62.11 and 192.31 mg/g, respectively and each $R^2$ was calculated as 0.71 and 0.98 by applying Langmuir isothermal adsorption equation. Biosorption for Cd was considered as monomolecular adsorption to single layer on the surface of cells, whereas biosorption for Pb was considered as accumulation process into the cell by the microbial metabolism and precipitation reaction with anion of bacteria.

• Economic and Environmental Geology
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• v.32 no.1
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• pp.53-62
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• 1999

The possibility of heavy metal pollution by contaminated roadside soils was studied under controlled conditions. The soil samples from roadside and those from a retention pond consisting of settling particles were characterized by the XRD analyses and the sequential extraction experiments. Characterization by sequential extraction, for roadside soil indicates elevate total concentrations of heavy metals. The leaching behavior of the samples under different pH and time conditions were also studied. Differences between both types of samples result mainly from the buffering effect of carbonates, present in roadside soils and lacking from settling particles. Acid leaching of the settling particles is equivalent to the sum of FI+FII+FIII, while the amounts leached from roadside soil are lower probably from kinetic reasons. The buffering effects of carbonates were found to greatly delay the onset of the leaching reactions and the extent of dissolution in most metals except for Ca and Mn. The study of leaching kinetics at pH of 6.5 and 5 showed that Cd and Zn reached the maximum possible concentration within 3 days, while Pb did not show any sign of dissolution at both ph values. The absolute amounts of dissolved Cd and Zn increased by 7 to 9 times by decreasing the pH from 6.5 to 5, indicating slightly acidified rain may result in significant metal dissolution. As deduced from both sequential extraction and leaching experiments, the relative mobility of heavy metals is found to be : Mn=Cd>Zn>>Pb>Fe, in spite of large differences in heavy metal contents and localizations.

• Journal of Environmental Health Sciences
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• v.18 no.1
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• pp.22-33
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• 1992

In Iri industrial area, Heavy metals in ait of the factories, 10 metal and 8 non-metal factories, were examined for ten months(from Feb. to Nov, 1991). The methals in blood, urin and hair of 232 employees who have worked in the factories were also examined at the same time The results are summarized as follows 1. Heavy metals Pb, Cd and Mn in the metal factories were 0.031mg/m$^{3}$, 0.0065mg/m$^{3}$, and 0. 035mg/m$^{3}$ respectively, but 0.017mg/m$^{3}$, 0.021mg/m$^{3}$ and 0.014mg/m$^{3}$ in non-metal factories. 2. Heavy metals such as Pb, Cd and Mn in blood from employees in the metal factories were measured : 22.36$\mu$g/dl, 0.27$\mu$g/dl and 1.26$\mu$g/dl respectively, The values in the non-metal factories were 19.84$\mu$g/dl, 0.21$\mu$g/dl and 1.24$\mu$g/dl. 3. Heavy metals such as Pb, Cd and Mn in urine from employees in the metal factories were measured 32.94$\mu$g/l, 0.16$\mu$g/dl, and 1.60$\mu$g/dl respectively, whereas the values in the non-metal factories were 28.79$\mu$g/l, 0.13$\mu$g/dl and 1.35$\mu$g/l. 4. Heavy metals such as Pb, Cd and Mn in hair from employees in the metal factories were measured 8.92mg/kg, 0.33mg/kg and 3.71mg/kg respectively, but 8.14mg/kg, 0.31mg/kg and 3.26 rng/kg in the non-metal factories.

• Ocean and Polar Research
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• v.35 no.4
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• pp.453-464
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• 2013

Heavy metals in the mangrove sediments of Chuuk and Kosrae, Federated States of Micronesia were analyzed to examine the pollution levels of heavy metals using enrichment factor (EF) and pollution load index (PLI). The mean concentrations of Cr, Ni, Cu, Zn, As, Cd and Pb in surface mangrove sediments were 642, 125, 46.9, 149, 15.6, 0.14 and 8.55 ${\mu}g$, respectively. Kosrae mangrove sediments showed the highest concentrations of Cr and Ni while Chuuk contains more of other metals such as Cu, Zn, As, Cd and Pb. Compared to those from other mangrove regions of the world, Cr, Ni and As levels in mangrove sediments from Micronesia were at higher levels whereas Cu, Zn, Cd and Pb were at lower to median levels. In core sediment of Chuuk, metal concentrations in the upper part were higher than those in the lower part. Based on the EF and PLI values, As is evaluated as the heaviest contaminant in the surface sediment from Micronesia whilst other metals (Cr, Ni, Cu, Zn, Cd and Pb) are present at slightly lesser levels.

• Journal of Korean Society on Water Environment
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• v.34 no.2
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• pp.157-163
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• 2018

This study aims to determine the pollution levels of nine kinds of heavy metals (As, Cd, Cu, Cr, Hg, Mn, Ni, Pb, and Zn) in Lake Shihwa, which is susceptible to the inflow of pollutants, and the levels of heavy metal exposure in its fish and shellfish. Shihwa Lake's water quality did not exceed the short-term standard for protection of marine ecosystems, but concentrations of As, Cu, Cr, Hg, Ni, and Zn exceeded the long-term standard for protection of a marine ecosystem. In comparison to findings in prior research, performed in 2010, levels of Cr, Ni, As, and Zn are now 4.1 times lower. However, when compared to Saemangeum Lake, the environment is similar to that of Lake Shihwa, Cu, Ni, Hg, Mn, and Zn were 244.4 times higher. The levels of Pb, Cd, and Hg in fish's muscles did not exceed the average values set by the marine safety standard. However, when compared to the fish from the Korean coast, the levels of heavy metals were 9.7 times higher, on average. The levels of heavy metals in fish's livers were on average 26.8 times higher than in the muscles. In the case of shellfish, the levels of Pb, Cd, and Hg did not exceed the standard values, but in comparison to the shellfish from the south coast, the levels of heavy metals were 6.2 times higher on average. In particular, Mn (153.5 times higher) from fish and Cd (14.7 times higher) from shellfish were found in high amounts, indicating a concerning level of these specific heavy metals.

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.2
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• pp.119-126
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• 1979

Rice seeds, suweon 264, were germinated under 5 levels of toxic heavy metals, Cd(0, 0.05, 0.5, 5, 20ppm), Cu(0, 0.05, 0.5, 5, 20, ppm), Cr(0, 0.5, 1, 5, 10ppm), Ni(0, 0.5, 1, 5, 10ppm), Co(0, 0.5, 1, 5, 10ppm), Zn(0, 0.5, 5, 20, 40, ppm), Pb(0, 0.5, 5, 20, 40ppm) and Mn(0, 1, 10, 25, 50, ppm) in culture solution, and then grown with supplying culture solution contained respective concentrations. Germination and growth response to the toxic heavy metals were studied. Results obtained are as follows : 1) The germination injury of rice seeds by excess concentration of toxic heave metal in culture solution occured in Cd and Cu; below 0.05 ppm, Ni; below 0.5 ppm, Mn; below 1.0 ppm, Co and Cr; 0.5-1.0 ppm, and 0.5-5 ppm, Zn and Pb. Thereby, in the order of degrees of the elements toxicity to germination, they were arranged as follows : Cd>Cu>Ni>Co>Cr>Mn>Zn$$\geq_-$$Pb. 2) Toxic heavy metal concentrations in culture solution, which result in decreasing dry weight due to the injury of excess concentration of treated elements, were Cd: below 0.05 ppm, Ni, Cr and Co; below 0.5 ppm, Cu and Zn; 0.5-5 ppm, Pb; 5-20 ppm and Mn; 10-25 ppm. The order was Ni>Cd>Cr>Co>Cu$$\geq_-$$Zn>Pb>Mn. 3) The critical contents of Cd, Ni, Pb, Cu, Zn, Mn, and Co in dry matter, Which result in decreasing dry weight, were considered to be 0.05-15.5, 1.50-25.0, 24.0-28.0, 26.5-62.5, 470-645.0, 231.0-500.0 and below 15.0 ppm, respectively. 4) The contents of Cr, Co, Cd, Pb, Ni, Cu and Zn in dry matter by 0.5 ppm treatment concentration of each heavy metals was trace, 15.0, 17.5, 24.0, 25.0, 84.5 and 470.0 ppm, respectively. Thereby, in the order of each element to uptaked by rice seedlings, they were arranged as follow; Zn>Cu>Ni>Pb>Cd>Co>Cr. 5) The hazardous concentrations of root activity by toxic heavy metals in culture solution were Cd; below 0.05, Cu; 0.05-0.5, Cr; below 0.5, Ni; 0.5-1.0, Co; 0.5-1.0, Zn; above 0.5, Pb; 0.5-5.0 and Mn; 1.0-10.0 ppm. The hazardous degree of root activity by toxic heave metals was in the order of Cd>Cu>Cr>Zn>Ni>Co>Pb>Mn.

• Journal of Food Hygiene and Safety
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• v.15 no.4
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• pp.324-327
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• 2000

The analysis of hazardous heavy metals, such as Pb, Cd and As, was conducted from the porcelain dinnerwares. Total 374 samples of those products in the domestic market were purchased for the study. All the samples were extracted by 4% acetic acid solution, followed by the analysis with AAS(Atomic Absorption Spectroscopy). As a result, Pb and As were detected maximum 8.63$\mu\textrm{g}$/ml, 2.58 ng/ml, respectively. Cd was fecund in a sample as 0.10$\mu\textrm{g}$/ml.

• Advances in environmental research
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• v.6 no.1
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• pp.67-81
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• 2017

Mining activities play a significant role in environmental pollution by producing large amounts of tailings which comprise heavy metals. The impressive increase in mining activities in recent decades, due to their high influence on the industry of developing countries, duplicates the need for a substantial effort to develop and apply efficient measures of pollution control, mitigation, and abatement. In this study, our objective was to investigate the effect of simulation of the leachate, pH and inflow intensity of transport of $Pb^{2+}$, $Zn^{2+}$, and $Cd^{2+}$ through Lakan lead and zinc plant tailings, in Iran, and to evaluate the modeling efficiency by comparing the modeling results and the results obtained from previous column studies. We used the HP1 model and the PHREEQC database to simulate metals transport through a saturated soil column during a 15 day time period. The simulations assumed local equilibrium. As expected, a lower pH and inflow intensity increased metal transport. The retardation of heavy metals followed the order $Zn^{2+}$ > $Pb^{2+}$ > $Cd^{2+}$ and the removal concentrations of Cd, Pb, and Zn at the inflow intensity critical scenario, and Cd and Pb at inflow acidity critical scenario exceeded the allowable EPA and Iranian's 1053 standard thresholds. However, although the simulation results generally agreed well with the results of the column study, improvements are expected by using multi-dimensional models and a kinetic modeling approach for the reactions involved. The results of such investigations will be highly useful for designing preventative strategies to control reactive transport of hazardous metals and minimize their environmental effects.