• Journal of Korean Society of Environmental Engineers
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• v.30 no.4
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• pp.423-429
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• 2008

Application of manganese-impregnated activated carbon(Mn-AC) in the treatment of synthetic wastewater containing both organic and inorganic contaminants was investigated. Phenol and As(III) was used as representative organic and inorganic contaminants, respectively. When the stability of Mn-AC at acidic condition was evaluated with variation of solution pH ranging from 2 to 4, Mn-AC was unstable below pH 3, while negligible dissolution of Mn was observed above pH 4. This stability test suggests a plausible applicability of Mn-AC in the treatment of wastewater above pH 4. Compared to AC-alone, the adsorption rates of phenol as well as adsorbed amounts of phenol by Mn-AC were slightly decreased due to the decrease of the surface area by impregnation. The maximum adsorbed amount of phenol by Mn-AC was corresponds to 75% of that by AC-alone from the adsorption isotherm study. The oxidation efficiency of As(III) by Mn-AC was greater than that by AC-alone at lower pHs while reverse trend was observed as pH increased above 7. From this work, it was found that Mn-AC could be used in the simultaneous treatment of both phenol and As(III).

• Journal of Soil and Groundwater Environment
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• v.16 no.1
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• pp.42-50
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• 2011

Potential risk of heavy metals to various receptors including humans depends on the bioavailability of the heavy metals in soil. In this study, the heavy metal extraction methods using 0.1N HCl and aqua regia were compared with the Tessier's sequential extraction method to assess whether these two methods can be used to determine the plant-available heavy metal concentrations. The contamination characteristics of copper (Cu), cadmium (Cd), lead (Pb), and arsenic (As) found in soils collected from 75 sites around the closed Janghang smelter were analyzed by extracting heavy metals using 0.1 N HCl, aqua regia, and the Tessier's sequential extraction method. The portion of metals bioavailable to plants is considered as the sum of the fraction 1 (exchangeable) and the fraction 2 (carbonates binding) of the Tessier's 5-step sequential extraction method, which were determined to be 3.1 ${\pm}$ 3.82, 0.6 ${\pm}$ 0.15, 20.6 ${\pm}$ 18.78, and 7.0 ${\pm}$ 6.48 mg/kg for Cu, Cd, Pb, and As, respectively, in this study. When the extraction using aqua regia and the Tessier's extraction method were compared, the extracted Cu and Pb concentrations did not show significant differences, whereas the extracted Cd and As concentrations showed significant differences. These results indicate that the portion of Cd and As in the fraction 5 of the Tessier's sequential extraction can not be extracted using aqua regia. Using aqua regia, which is the official test method, higher concentrations of Cu, Cd, Pb and As were extracted than the sum of the fraction 1 and 2. The results show that only 9, 40, 39 and 10% of Cu, Cd, Pb and As using aqua regia can be uptaken by plants (i.e., plant-available). Using 0.1N HCl, the portion of Cd equivalent to about 66% the fraction 1 could be extracted, while, with Pb, the portion of the fraction 1 and about 90% of the fraction 2 could be extracted. With As, the portion equivalent to the fraction 1, 2 and 79% of the fraction 3 was extracted, while with Cu, the portion equivalent to the fraction 1, 2, 3 and 20% of the fraction 4 was extracted using 0.1N HCl.

• Journal of the Mineralogical Society of Korea
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• v.32 no.1
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• pp.1-14
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• 2019

This study used microwave-nitric acid leaching with the aim of removing penalty elements such as As and Bi. Moreover, enhanced gold content from the gold concentrate sample. The leaching conditions were changed: leaching time, nitric acid concentrations and solid-liquid ratio; In order to improve the removal of penalty elements. As a result of the experiment; sample weight loss rate, As and Bi removal rate and gold content in the solid-residues have been increased when the nitric acid concentration and leaching time were increased while the solid-liquid ratio was decreased. The leaching conditions for the maximum As and Bi removal and gold content were: leaching with a 6.0 M nitric acid solution doing 5 min. At these, the solid-residue sample weight loss was 87 %. As removal rate was 98.23 % and Bi was completely removed (100 %). Furthermore, gold content increased from 81.36 g/t to 487.32 g/t. The XRD of the solid residue showed that pyrite disappeared as the nitric acid concentration was increased, whereas sulfur peaks was increased, too.

• Analytical Science and Technology
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• v.19 no.4
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• pp.342-351
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• 2006

This study was carried out to estimate the contents of heavy metals in big marine 17 kinds of fishes (n=89) which had been sold at wholesale market in Seoul from January to December in 2005. The contents of mercury (Hg), lead (Pb), cadmium (Cd), chrome (Cr), copper (Cu) and arsenic (As) were measured by the mercury analyzer and atomic spectrophotometer (AAS) in the flesh, liver, and gill part. The values of heavy metals in fishes were as follows ($Mean{\pm}SD$, mg/kg). The average contents of heavy metals in the fishes were Hg $0.08{\pm}0.01mg/kg$, Pb $0.17{\pm}0.32mg/kg$, Cd $0.34{\pm}0.07mg/kg$, Cr $0.05{\pm}0.05mg/kg$, Cu $1.14{\pm}0.13mg/kg$, As $0.24{\pm}0.22mg/kg$. Of the heavy metals detected in 3 parts, liver was measured highly in the all heavy metals. Of the heavy metals detected in countries, Hg, Pb, and Cu were measured highly in New Zealand, Cd and As in Norway, Cr in Korea. The range of heavy metal contents in imported and domestic fishes are low level, except of mercury contents of imported Yellow porgy (n=2), compared with regulation value of anther nations and Korea. And the contents of heavy metal in the imported fishes are natural. By correlation coefficients between fish livers of all subjects, a significant correlation was found Hg (r=0.989, p<0.01), Pb (r=0.978, p<0.01), Cd (r=0.991, p<0.01), Cu (r=0.998, p<0.01), As (r=0.198, p<0.05) in fish livers and flesh.

• Journal of Soil and Groundwater Environment
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• v.13 no.2
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• pp.62-69
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• 2008

In this study physicochemical characteristics and stability of various manganese coated sands (MCS) prepared with different methods were evaluated. In addition, removal efficiencies of As(III) by each MCS were compared. Four different MCSs were used; B-MCS prepared by baking method, W&D-MCS prepared by wetting and dry method, NMCS prepared during the water treatment process and Birm which is a commercial MCS widely used for the removal iron and manganese. The manganese content in each MCS was following order: Birm (63,120 mg/kg) > N-MCS (10,400 mg/kg) >W&D-MCS (5,080 mg/kg) > B-MCS (2,220 mg/kg). Birm showed the least solubility (% basis) in acidic conditions. As(III) oxidation efficiency of B-MCS was continuously increased as the solution pH decreased. While As(III) oxidation efficiency of N-MCS and Birm was minimum around neutral pH. The increased As(III) oxidation efficiency above neutral pH for N-MCS and Birm could be due to the competitive adsorption of $Mn^{2+}$, which was produced from reduction of $MnO_2$, onto the surface of aluminum and manganese oxides.

• Journal of Food Hygiene and Safety
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• v.13 no.3
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• pp.201-205
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• 1998

In Korea, a small proportion of fishery products are contaminated with a considerable amount of potentially hazardous contaminants. So, there is generally a high risks to consumers. Inorganic contaminants with the greatest potential for toxicity are Sb, As, Cd, Pb, Hg, Se and the Sulfides. As appears to be much more variable than the others. This study was performed to assess the levels of the As in fisheries caught from the waters of the western coast of Korea. The samples included 26 kinds of fishes, 18 kinds of Mollusca, 3 kinds of Crustacea and 7 kinds of salted fishes. The Moisture content of molluscans was significantly higher than that of others (p<0.05). And the As contents of crustaceans were significantly higher than those of fishes, molluscans and salted fishes (p<0.05). The As content of Turban shell was 51.62 ppm, which was the highest among the samples. Also, the As contents of eel, cuttle fish and blue crab were found to be higher than in other fisheries. This variability offers a solution for the reduction of exposure to As through restricting the harvest of aquatic organism from the western coast of Korea.

• Journal of Environmental Health Sciences
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• v.43 no.2
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• pp.103-110
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• 2017

Objectives: This study was performed to provide basic data for the re-establishment of standards (criteria) and analytical methods for hazardous metals in nail enamel. Methods: Ten metals (lead; Pb, arsenic; As, cadminum; Cd, antimony: Sb, cobalt; Co, nikel; Ni, copper; Cu, chromium; Cr, aluminum; Al, and mercury; Hg) were measured in 67 commercial nail enamels containing glitter and/or pearls. The content of hazardous metals (excepting Hg) was determined by using an inductively coupled plasma-optical emission spectrophotometer (ICP-OES) after microwave digestion. Mercury content was measured by a mercury analyzer without any preparation. Results: The detected ranges of the intact samples were as follows: $ND-1.756{\mu}g/g$ for Pb, $ND-1.24{\mu}g/g$ for As, ND for Cd, $ND-20.41{\mu}g/g$ for Sb, $ND-12.36{\mu}g/g$ for Co, $ND-7.908{\mu}g/g$ for Ni, $0.088-79.27{\mu}g/g$ for Cu, $0.281-18.54{\mu}g/g$ for Cr, $13.78-3563{\mu}g/g$ for Al, and $ND-0.044{\mu}g/g$ for Hg. After centrifugation, the detected ranges of supernatant were as follows: $ND-0.435{\mu}g/g$ for Pb, $ND-0.504{\mu}g/g$ for As, ND for Cd, $ND-0.035{\mu}g/g$ for Sb, $ND-13.17{\mu}g/g$ for Co, $ND-0.232{\mu}g/g$ for Ni, $0.117-90.07{\mu}g/g$ for Cu, $0.174-2.787{\mu}g/g$ for Cr, and $9.459-1565{\mu}g/g$ for Al. The results of this analysis showed that the levels of heavy metals such as Pb, As, and Sb were much higher in the intact samples than those of supernatant. Conclusion: In the present study, we found that the levels of hazardous metals were significantly different depending on the status of the presence of glitter. Based on the results, we recommend that the product consumer refrain from prolonged application of nail enamel, avoid biting or chewing the nails, and wear gloves during cooking and washing dishes.

• Asian Journal of Atmospheric Environment
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• v.6 no.2
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• pp.83-95
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• 2012

China has been a top producer and exporter of refined lead products in the world since the year 2000. After the phasing-out of leaded gasoline in the late 1990s, non-ferrous metallurgy and coal combustion have been identified as potential major sources of aerosol lead in China. This paper presents the single particle analytical results of ambient aerosol particles collected near a lead smelter using a scanning electron microscopy- energy dispersive x-ray spectroscopy (SEM-EDX). Aerosol particle samples were collected over a 24-hour period, starting from 8 pm on 31 May 2002, using a high volume TSP sampler. For this near source sample, 73 particles among 377 particles analyzed (accounting for 19.4%) were lead-containing particles mixed with other species (S, Cl, K, Ca, and/or C), which probably appeared to be from a nearby lead smelter. Lead-containing particles of less than $2{\mu}m$ size in the near source sample were most frequently encountered with the relative abundances of 42%. SEM-EDX analysis of individual standard particles, such as PbO, PbS, $PbSO_4$, $PbCl_2$, and $PbCO_3$, was also performed to assist in the clear identification of lead-containing aerosol particles. Lead-containing particles were frequently associated with arsenic and zinc, indicating that the smelter had emitted those species during the non-ferrous metallurgical process. The frequently encountered particles following the lead-containing particles were mineral dust particles, such as aluminosilicates (denoted as AlSi), $SiO_2$, and $CaCO_3$. Nitrate- and sulfate-containing particles were encountered frequently in $2-4{\mu}m$ size range, and existed mostly in the forms of $Ca(NO_3,SO_4)/C$, $(Mg,Ca)SO_4/C$, and $AlSi+(NO_3,SO_4)$. Particles containing metals (e.g., Fe, Cu, and As) in this near source sample had relative abundances of approximately 10%. Although the airborne particles collected near the lead smelter contained elevated levels of lead, other types of particles, such as $CaCO_3$-containing, carbonaceous, metal-containing, nitrates, sulfates, and fly-ash particles, showed the unique signatures of samples influenced by emissions from the lead smelter.

• Journal of Food Hygiene and Safety
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• v.28 no.1
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• pp.45-49
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• 2013

This study aimed to determine heavy metal contents in sesame oil samples produced in Korea through microwave-assisted acid digestion without using an emulsifier. Three heavy metal, cadmium (Cd), lead (Pb) and arsenic (As) in twelve sesame oil samples were determined by ICP-MS. The validation of analysis method was checked by standard addition method (10 and $100{\mu}g/kg$). As a result, linearity ($R^2$) was above 0.999 and RSDs were lower than 4%. The recovery of Cd, Pb and As ranged between 98.5-101.6%, 100.3-101.3%, and 102.1-111.2%, respectively. The detected ranges in sesame oil samples were as follows; N.D. to $0.109{\mu}g/g$ for Cd, 0.014 to $0.200{\mu}g/g$ for Pb and 0.014 to $0.125{\mu}g/g$ for As, respectively. Therefore, sesame seeds and products grown in heavy metal-polluted regions which are used as food should be given priority attention and consideration.

• Journal of Environmental Health Sciences
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• v.48 no.4
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• pp.236-243
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• 2022

Background: In the case of multiple exposures to different types of heavy metals, such as the conditions faced by residents living near a smelter, it would be preferable to group hazardous substances with similar characteristics rather than individually related substances and evaluate the effects of each group on the human body. Objectives: The purpose of this study is to evaluate the utility of factor analysis in the assessment of health effects caused by exposure to two or more hazardous substances with similar characteristics, such as in the case of residents living near a smelter. Methods: Heavy metal concentration data for 572 people living in the vicinity of the Janghang smelter area were grouped based on several subfactors according to their characteristics using factor analysis. Using these factor scores as an independent variable, multiple regression analysis was performed on health effect markers. Results: Through factor analysis, three subfactors were extracted. Factor 1 contained copper and zinc in serum and revealed a common characteristic of the enzyme co-factor in the human body. Factor 2 involved urinary cadmium and arsenic, which are harmful metals related to kidney damage. Factor 3 encompassed blood mercury and lead, which are classified as related to cardiovascular disease. As a result of multiple linear regression analysis, it was found that using the factor index derived through factor analysis as an independent variable is more advantageous in assessing the relevance to health effects than when analyzing the two heavy metals by including them in a single regression model. Conclusions: The results of this study suggest that regression analysis linked with factor analysis is a good alternative in that it can simultaneously identify the effects of heavy metals with similar properties while overcoming multicollinearity that may occur in environmental epidemiologic studies on exposure to various types of heavy metals.