• Journal of Korean Society of Water Science and Technology
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• v.26 no.6
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• pp.13-26
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• 2018

This research was conducted to elucidate the removal mechanism of heavy metals and sulfate ion from acid mine drainage(AMD) by porous zeolite-slag ceramics (ZS ceramics) packed in a column reactor system. The average removal efficiencies of heavy metals and sulfate ion from AMD by the 1:3(Z:S) porous ZS ceramics in the column reactor under the HRT condition of 24 hours were Al 97.5%, As 98.8%, Cd 86.1%, Cu 96.2%, Fe 99.7%, Mn 64.1%, Pb 97.2%, Zn 66.7%, and $SO_4{^{2-}}$ 76.0% during 121 days of operation time. The XRD analysis showed that the ferric iron from AMD could be removed by adsorption and/or ion-exchange on the porous ZS ceramics. In addition it was known that Al, As, Cu, Mn, and Zn could adsorb or coprecipitate on the surface of Fe precipitates such as schwertmannite, ferrihydrite, or goethite. The EDS analysis revealed that Al, Fe, and Mn, which were of relatively high concentration in the AMD, would be adsorbed and/or ion-exchanged on the porous ZS ceramics and also exhibited that Al, Cu, Fe, Mn, and Zn could be precipitated as the form of metal hydroxide or sulfate and adsorbed or coprecipitated on the surface of Fe precipitates. The microscopic results on the porous ZS ceramics and precipitated sludge in a column reactor system suggested that the heavy metals and sulfate ion from AMD would be eliminated by the multiple mechanisms of coprecipitation, adsorption, ion-exchange as well as precipitation.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.9 no.1
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• pp.56-72
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• 1999

Airborne concentrations of welding fumes in which 13 different metals such as Al, Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Si, Sn, Ti, and Zn were analyzed were measured at 18 factories including automobile assembly and manufactures, steel heavy industries and shipyards. Air samples were collected by personal sampler at each worker's worksite(n=339). Blood levels of Cd, Cu, Fe, Mn, Pb and Zn were also measured from samples taken from 447 welders by atomic absorption spectrometry and compared with control values obtained from 127 non-exposed workers. The results were as follows ; 1. Among various welding types, $CO_2$ welding 70.2 % were widely used, shielded metal arc welding(SMAW) 22.1 % came next, and rest of them were metal inert gas(MIG) welding, submerged arc welding(SAW), spot welding(SPOT) and tungsten inert gas(TIG) welding. 2. Welding fume concentration was $0.92mg/m^3$($0.02{\sim}15.33mg/m^3$) at automobile assembly and manufactures, $4.10mg/m^3$($0.02{\sim}70.75mg/m^3$) at steel heavy industries and $5.59mg/m^3$($0.30{\sim}91.16mg/m^3$) at shipyards, respectively, showing significant difference among industry types. Workers exposed to high concentration of welding fumes above Korean Permissible Exposure Limit(KPEL) amounted to 7.9 % and 12.5 %, in $CO_2$ welding and in SMAW at automobile assembly and manufactures and 62.7 % in $CO_2$ welding, and 12.5 % in SMAW at shipyards, and 66.2 % in $CO_2$ welding and 70.6 % in SMAW at steel heavy industries. 3. Geometric mean of airborne concentration of each metal released from welding fumes was below one 10th of KPEL in all welding types. Percentage of workers, however, exposed to airborne concentration of metals above KPEL amounted to 16.8 % in Mn and 7.6 % in Fe in $CO_2$ welding; 37.5 % in Cu in SAW, 30 % in Cu in TIG; and 25 % in Pb in SPOT welding. As a whole, 76 Workers(22.4%) were exposed to high concentration of any of the metals above KPEL. 4. There were differences in airborne concentration of metals such as Al, Cd, Cr, Cu. Fe. Mn, Mo, Ni, Pb, Si, Sn, Ti and Zn by industry types. These concentrations were higher in shipyards and steel heavy industries than in automobile assembly and manufactures. Workers exposed to higher concentration of Pb above KPEI amounted to 7.4 % of workers(7/94) in automobile assembly and manufactures. In shipyards, 19.2 % of workers(19/99) were over-exposed to Mn and 7.1 % (7/99) to Fe above KPEL. In steel heavy industries, 14.4 %(21/146), 7.5 %(11/146) and 13 %(19/146) were over-exposed to Mn, Fe and Cu, respectively. As a whole, 76 out of 339 workers(22.4%) were exposed to any of the metals above KPEL. 5. Blood levels of Cd, Cu, Fe, Mn, Pb, and Zn in welders were $0.11{\mu}g/100m{\ell}$, $0.84{\mu}g/m{\ell}$, $424.4{\mu}g/m{\ell}$, $1.26{\mu}g/100m{\ell}$, $5.01{\mu}g/100m{\ell}$ and $5.68{\mu}g/m{\ell}$, respectively, in contrast to $0.09{\mu}g/100m{\ell}$, $0.70{\mu}g/m{\ell}$, $477.2{\mu}g/m{\ell}$, $0.73{\mu}g/100m{\ell}$, $3.14{\mu}g/100m{\ell}$ and $6.15{\mu}g/m{\ell}$ in non-exposed control groups, showing significantly higher values in welders but Fe and Zn.

• Economic and Environmental Geology
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• v.27 no.5
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• pp.469-477
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• 1994

Many researchers have investigated most representative sequential extraction method using various reagents for determining the chemical forms of metals in soils and sediments. In this paper, a newly modified method for sequential extraction scheme based on Tessier's method by Environmental Geochemistry Research, Centre for Environmental Technology, Imperial College, was introduced and examined. In comparison with Tessier's method, originally designed for sediment analysis by Atomic Absorption Spectrophotometry (AAS), the sequential extraction scheme has been developed for the multi-element analysis by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The partitioning of particulate trace elements was classified into five fractions: (i) exchangeable, (ii) bound to carbonates or specially adsorbed, (iii) bound to Fe and Mn oxides, (iv) bound to organic matter and sulphides and (v) residuals. The experimental results of the pilot study for in-house reference material (HRM2) and certified international standard reference material (SRM2711) using the modified method showed not only reasonable precision and accuracy but also acceptable overall recovery rates. In addition, mine dump soils sampled in the Dalsung Cu-W mine, Korea were prepared and sequentially extracted using the method. Most of Cu was bound to organic matter/sulphides and residual fractions. The dominant fraction of soil Pb and Zn in the study area was found in the residuals. The fraction of Cd showed a wide variation between samples and could be found bound to the carbonates or specially adsorbed, oxides, organic fraction and residuals. The recovery rates of Cd, however, were poor due to relatively low Cd concentrations in soils. The heavy metals in these mine dumps appear to be in the more inert forms and should not be readily bioavailable. The soils, however, had very low pH values (average 4.1) and had sandy textures; consequently, rapid infiltration of rainfall may increase leaching of Zn and Cd which were found to be around 5 to 10% of the exchangeable fraction. As a result of the investigation of this study, it has been strongly recommended that these mine waste materials should still be considered a significant contaminant source and will need environmental remediation to prevent pollutants from being released into the environment.

• Korean journal of food and cookery science
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• v.4 no.1
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• pp.53-57
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• 1988

To obtain basic data for the development of domestic tea manufacture, the physico-chemical properties were analyzed. The content of crude fiber in domestic black tea was abundant of 50%, as compared with those in Sri-Lanka's black tea, while the contents of tanin and caffeine were lower than those of Sri-Lanka's Products. The quantities of mineral in Sri-Lanka's products were determined as 300ppm P, 15,000ppm K, 1,400ppm Mg, 4,000ppm Ca, 22ppm Cu, 21ppm Cr and 45ppm Zn. These contents were higher than those of domestic products. Al content was 4,100ppm in domestic products. Pb and Cd were not detected in two kinds of black tea products. In Sri-Lanka's black tea, 8 kinds of organic acids were identified and the major organic acids were shikimic, citric and quinic acid, while 6 kinds of organic acids were identified in domestic products and were quinic and gallic acid, as the major organic acids. The content of sucrose was higher than that of Sri-Lanka's product and theaflavin, thearubigin and theobromine were abundant, as compared with those in domestic products.

• Nuclear Engineering and Technology
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• v.51 no.8
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• pp.2042-2049
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• 2019

Ten gizzard and three flesh samples of the broiler were collected from different locations in Tehsil Gujar Khan District Rawalpindi, Pakistan. The samples were dried, crushed and ground. Pellets were prepared by pressing the powder of the samples and that of the Bovine liver 1577c reference material obtained from NIST, USA. Proton induced X-ray emission (PIXE) installed at National Center for Physics, Islamabad, Pakistan has been used as a reliable and improved technique to determine concentration of various major/trace and toxic elements e.g. S, Cl, K, Ca, Cl, Fe, Cu, Mn, Co, Zn, Ti, Cd, Ga, Cr, V and Ni, in the Gizzard and Flesh samples of the broiler. The concentrations of all the detected elements in the samples are statistically significant. The certified and measured values of the elements in the reference material were in agreement with each other within a deviation of 7%. S, Cl, K and Ca are within tolerable limits and are good for human consumption. Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn were more than the acceptable limits of World Health Organization, WHO whereas Ga, As, Sn, Sb and Pb are not detected in most of the samples.

• Economic and Environmental Geology
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• v.37 no.1
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• pp.87-98
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• 2004

Tailings and contaminated soils from Cheongyang mine and Seobo mine have been analysed by ICP-AES from 5-step sequential extraction method of multielement determination on extraction solutions at each step. As and Co within tailings and contaminated soils from Cheongyang mine and Seobo mine are mainly in the residual phase. In case of Cd, Cu and Zn, the most dominant fraction for tailings of Cheongyang mine is the oxidizable phase, while tailings of Seobo mine is dominated by the residual phase. In contaminated soils from Seobo mine, the predominant fraction for Cd, Cu and Zn is the Fe-Mn oxide phase. The exchangeable fraction of Pb in tailings from Cheongyang mine and Seobo mine is relatively high compared with those of other metals; whereas Pb fraction in contaminated soils from Seobo mine is largely associated with the residual fraction.

• Economic and Environmental Geology
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• v.38 no.6 s.175
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• pp.699-705
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• 2005

In order to identify the speciation of As and trace elements which are contained weathered waste rocks on the abandoned Jangpoong Cu mine area, five fraction sequential extraction was carried out. Concentrations of the extraction solutions which were acquaired each fraction were mesured by ICP-AES. Mineral characters of weathered waste rocks were determinated by XRD. The weathered waste rocks could divide into two types (Type I and type II). Type land type II weathered waste rocks are mainly composed of a quartz and a calcite, respectively. The most dominant speciation of As, Co and Fe is residual phase. Most of the speciation of Cd, Mn and Zn is residual phase for type I and Fe-Mn oxide phase for type II. In case of Cu, residual phase is predominant in type I and sulfide is predominet in type II. The most dominant speciation of Pb for type I and type II is associated with the residual phase and Fe-Mn oxide phase, respectively. At pH 4-7 range, the order of relative mobility considers Zn>Cu>Cd>Pb>Co>AS in type I, and Cd>Cu>Zn>Pb>As>Co in type II.

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.3
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• pp.29-38
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• 2016

There have been only a few studies focused on the stabilization of metal (loid)s in anaerobic soils such as paddy soils. In this study, laboratory-scale column tests were conducted to artificially manipulate anoxic conditions in submerged paddy fields and we observed the release behavior of As, Cd, Pb, and Zn, as well as to examine the stabilization effect of steel refining slag (SRS) on the metal(loid)s. The leachate samples were collected and chemical parameters were monitored during the test period. Results suggest that anoxic conditions were developed during submersion, and that As or heavy metals (particularly Cd) fractions bound to ferrous (Fe) /manganese (Mn) oxides were easily dissociated. Moreover, As is also reduced by itself to a trivalent form with higher mobility in the reducing environment of rice paddy soil. However, it was also shown that SRS significantly decreased the dissolution of Zn, Pb, Cd, and As in the the leachates; their removal rates in the SRS-treated soil were 66 %, 45 %, 24 %, and 84 %, respectively, of those in the control soil.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.333-338
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• 2016

The purpose of this study was to understand the pollution level of the surface sediment of Sihwa Lake by assessing its geochemical characteristics and investigating the spatial distribution of trace metals and organic matter. In the surface sediment of Sihwa lake, the mean grain size was between 2.94 and 6.35 Ø and the main type of sediment was sandy silt. The concentrations of As, Co, Cr, Ni, V and Li among the metal elements in the surface sediment were correlated with the mean crust concentration (p<0.05). Based on the strong correlation between the metals (Cd, Cu, Pb and Zn) and organic matter (Ignition Loss), the concentrations of these metal elements seem to be controlled by the organic matter dilution effect. The trace metal pollution level, determined by applying the Republic of Korea Marine environmental standard and the US National Oceanic and Atmospheric Administration's sediment quality guidelines, showed the pollution level of As to be either close to or in excess of the above-mentioned standards at almost all levels. The enrichment factor and geoaccumulation index of As showed that there was an incremental increase of pollution by elements other than V, Cr, Co, Fe, Al and Mn. Moreover, the nearby industrial area and dike were more polluted than the other areas, so the surface sediments in Sihwa lake should be monitored by taking into consideration the geological variations.

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.444-450
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• 2011

A novel method that utilizes poly(5-methyl-2-thiozyl methacrylamide-co-2-acrylamido-2-methyl-1-propanesulfonic acid-co-divinylbenzene) [MTMAAm/AMPS/DVB] as a solid-phase extractant was developed for simultaneous preconcentration of trace Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Mn(II), Ni(II), Pb(II), and Zn(II) prior to the measurement by flame atomic absorpiton spectrometry (FAAS). Experimental conditions for effective adsorption of the metal ions were optimized using column procedures. The optimum pH value for the simultaneously separation of the metal ions on the new adsorbent was 2.5. Effects of concentration and volume of elution solution, sample flow rate, sample volume and interfering ions on the recovery of the analytes were investigated. A high preconcentration factor, 100, and low relative standard deviation values, $\leq$1.5% (n = 10), were obtained. The detection limits (${\mu}gL^{-1}$) based on the 3s criterion were 0.18 for Cd(II), 0.11 for Co(II), 0.07 for Cr(III), 0.12 for Cu(II), 0.18 for Fe(III), 0.67 for Mn(II), 0.13 for Ni(II), 0.06 for Pb(II), and 0.09 for Zn(II). The validation of the procedure was performed by the analysis of two certified reference materials. The presented method was applied to the determination of the analytes in various environmental samples with satisfactory results.