• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.409-412
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• 2003

Total extraction of stream sediments in the Kwangyang mine area shows their significant pollution with most trace metals such as Cr, Co, Fe, Pb, Cu, Ni, Zn and Cd, due to sulfide oxidation in waste dumps. Calculations of enrichment factor shows that Chonam-ri creek sediments are more severely contaminated than Sagok-ri sediments. Using the weak acid (0.1N HCl) extraction and sequential extraction techniques, the transport and sediment-water partitioning of heavy metals in mine drainage were examined for contaminated sediments in the Chonam-ri and Sagok-ri creeks of the Kwangyang Au-Ag mine area. Calculated distribution coefficient (Kd) generally decreases in the order of Pb $\geq$Al > Cu > Mn > Zn > Co > Ni $\geq$ Cd. Sequential extraction of Chonam-ri creek sediments shows that among non-residual fractions the Fe-Mn oxide fraction is most abundant for most of the metals. This indicates that precipitation of Fe hydroxides plays an important role in regulating heavy metal concentrations in water, as shown by field observations.

• Journal of Radiation Protection and Research
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• v.25 no.2
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• pp.99-107
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• 2000

Through the results of off-gas analysis at 3 sampling points in Plasma Arc Melting vitrification pilot plant, it was evaluated the partitioning of spiked materials in off-gas and the decontamination characteristic of off-gas treatment system. Spiked materials are hazard_us heavy metals(Pb, Cd, Hg), radioactive surrogate(Co, Cs) and radioactive materials($^{60}Co,\;^{137}Cs$). Through the Trial burn tests, Decontamination factor of spiked materials in off-gas treatment system is calculated.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.10
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• pp.1072-1080
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• 2005

The extraction characteristics of heavy metals(HM) from a contaminated soil at existing lead smelters were investigated with ethylene diamine tetraacetic acid(EDTA), citrate and HCl as washing solutions. EDTA was more effective for Pb than for other heavy metals. As the mol ratio of EDTA/HM increased, the removal efficiency of heavy metals became higher. When the mol ratio of EDTA/HM approached to 6.5, it removed Pb most effectively. Citrate was effective especially in extracting Zn. The removal efficiency of HCl was comparatively high in almost all heavy metals, and at 0.3N concentration it was the highest. After soil washing process by the use of EDTA, the great part of exchangeable fractions and most of heavy metals of weakly adsorbed like carbonate fraction were extracted. For washing with citrate and HCl, four heavy metals showed the similar exchange of chemical partitioning and the exchangeable fractions of Pb which has weakly adsorbed to soil were more increased than before the process. As removal efficiency of citrate washing process depends upon the distribution of non-detrital fractions, so it can be contended that only the amount of non-detrital fractions could be removed from all the heavy metal content. EDTA and HCl could remove most of non-residual fractions in all heavy metals except Zn. As a result of EDTA washing, toxicity characteristic leaching procedure(TCLP) concentration of the processed soil met the USEPA Pb limit of 5.0 mg/L.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.40-43
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• 2002

Electrokinetic remediation was studied for the removal of toxic heavy metals from tailing soils. This study emphasized the dependency of removal efficiency upon heavy metal speciation, as demonstrated by different extraction methods (sequential extraction, total digestion, and 0.1 N HC1 extraction). The tailing soils examined showed different physicochemical characteristics, in view of initial pH, particle size distribution, and major mineral constituents, and contained high concentrations of target metal contaminants in various forms. The electrokinetic removal efficiency of heavy metals was significantly influenced by their partitioning prior to treatment, and by the pHs of the tailing soils. The mobile and weakly bound fractions of heavy metals, such as exchangeable fraction, were easily removed by electrokinetic treatment (more than 90% in removal efficiency), whereas immobile and strongly bound fractions, such as organically bound and residual fractions, were not effectively removed (less than 20% in removal efficiency).

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.187-190
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• 2002

Reductive dechlorination of endosulfans was studied with zero valent metals (ZVMs) and bimetals in aqueous batch reactors. The effect of surfactants was evaluated. Endosulfan was successfully dechlorinated with zero valent iron. However, a bimetal, palladium coated iron (Pd/Fe) showed a highly enhanced reactivity for both endosulfan I and II indicating palladium act as a dechlorination catalyst on the iron. The effect of surfactants on degradation with ZVM has been very controvertible. Variable concentration of a nonionic surfactant, Triton X-100 and an anionic surfactant, SDS were added into the reactor with ZVM. The reaction rates of endosulfan were increased with both surfactants. In the case of Triton X-100, the reaction rate was increased with the increasing surfactant concentration up to 400 mg/L. Addition of small amount of surfactant under the CMC, the reaction rate was increased. However, the enhancing effect was diminished when a higher concentration of surfactant (1,000 mg/L) was used. Current study implicate that the surfactant adsorbed on the metal surface might increase the surface concentration of endosulfan resulting in the increased reaction rate. However, partitioning of endosulfan into the micelle formed at the high concentration of surfactant diminish the enhancing effect by reducing the contact chance between target compound and the metal surface.

• Journal of the korean society of oceanography
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• v.39 no.4
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• pp.243-250
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• 2004

Sediment microcosm experiments were conducted for 14 and 28 days using Zn spiked sediment to examine the changing distribution of bioavailab1e sediment-bound Zn at different SEM (simultaneously extracted metal)-Zn/ AVS (acid volatile sulfide) mole ratios as a function of time and amphipod density. In surficial sediments (0-1cm), AVS concentrations significantly decreased due to bioturbation and oxidation, while SEM-Zn concentrations remained unchanged. As a result, SEM-Zn/AVS ratios in the surface sediment were greater one although the ratios were designed as less than one initially. With increasing SEM-Zn/AVS ratios in surficial sediments, concentrations of potentially bioavailable $MgCl_2$extractable-Zn, NaOAc extractable-Zn and pore water-Zn significantly increased, while concentrations of SEM-Zn were not significantly varied. Results suggested that as AVS concentrations decreased, AVS bound Zn was partitioned to other sediment fractions (i.e. $MgCl_2$ and NaOAc extractable) and the pore water, resulting in changes in Zn bioavailability in surficial sediments. Concentrations of AVS, SEM-Zn and pore water-Zn remained unchanged in the deeper layers (>1 cm) of the sediment.

• Journal of Soil and Groundwater Environment
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• v.11 no.5
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• pp.20-34
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• 2006

This study was undertaken to assess the anthropogenic impact on trace metal concentrations (Zn, Cu, Pb, Cr, Ni, and Cd) of roadside sediments (N = 70) from No.7 national road within the watershed of Hoidong Reservoir in Pusan City and to estimate the potential mobility of selected metals using sequential extraction. We generally found high concentrations of metals, especially Zn, Cu and Pb, affected by anthropogenic inputs. Compared to the trace metal concentrations of uncontaminated stream sediments, arithmetic mean concentrations of roadside sediments were about 7 times higher for Cu, 4 times higher for Zn, 3 times higher for Pb and Cr and, 2 times higher for Ni and As. Speciation data on the basis of sequential extraction indicate that most of the trace metals considered do not occur in significant quantities in the exchangeable fraction, except for Cd and Ni whose exchangeable fractions are appreciable (average 29.3 and 25.8%, respectively). Other metals such as Zn (51.4%) and Pb (45.2%) are preferentially bound to the reducible fraction, and therefore they can be potentially released by a pH decrease and/or redox change. Copper is mainly found in the organic fraction, while Cd is highest in the exchangeable fraction, and Cr and Ni in the residual fraction. Considering the proportion of metals bound to the exchangeable and carbonate fractions, the comparative mobility of metals probably decreases in the order of Cd>Ni>Pb>Zn>Cr>Cu. Although the total concentration data showed that Zn was typically present in potentially harmful concentration levels, the data on metal partitioning indicated that Cd, Ni and Pb pose the highest potential hazard for runoff water. As potential changes of redox state and pH may remobilize the metals bound to carbonates, amorphous oxides, and/or organic matter, and may release and flush them through drain networks into the watershed of Hoidong Reservoir, careful monitoring of environmental conditions appears to be very important.

• Journal of the Korean earth science society
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• v.24 no.8
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• pp.711-720
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• 2003

To study characteristics of the heavy metal pollution, sediment samples were collected at 67 sites on the roadside of Jeonju city during summer and winter, 2002. The total concentration of metals including Cd, Co, Cr, Cu, Ni, Pb, Zn, and Mn in the sediment samples were determined. The results indicate that the roadside sediments in Jeonju city have lower (1/2 to 1/7 times) concentrations of Zn, Cu, Pb and Cd than the metal concentrations previously reported for roadside soil, dust and sewage sludges in Seoul. However, the metal concentrations are higher than environmental quality criteria in soil suggested from several countries, and Zn, Cu, Pb and Cd contents are usually 2-7 times higher than the world average contents of the metals in natural soil. Although pollution index and concentrations of Cr, Ni, Pb and Zn in the roadside sediments at industrial area were usually higher than those of downtown and residential area, the metal having small vehicle- and steel-related industries had high concentrations of metals. The results of chemical partitioning analysis showed that Pb, Zn and Mn are mainly associated with carbonate/adsorbed and Fe-Mn oxide phases but that Cu is largely associated with the organic and sulfide fractions. It thus indicates that both large and small (vehicle- and steel-related) industries are main sources of heavy metal contamination. Due to high solubility of the carbonate phases by natural leaching episodes, the carbonate/adsorbed Cd, Co, Ni, Pb, Zn and Mn in the roadside sediments may serve as a potential source of contamination.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.100-101
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• 2004

Many researches in Korea have been performed to understand the pollution of stream waters by acid mine drainage. However, few studies have been conducted regarding the effect of particulate and colloidal fractions on the transport of trace metals. To estimate harmful effects of trace metals, it is important to evaluate the particulate and colloidal metals as well as dissolved metals, because particulate and colloidal fractions of trace metals play an important role in transport of trace metals and may adversely affect habitats and organisms in riverine system. Colloids are solids with effective diameters in size range from 0.001 $\mu$m to 1 $\mu$m. According to Jone et al. (1974), metals in surface water, like Al, Fe, and Mn, require filtration with pore-size membranes smaller than 0.45 $\mu$m to define dissolved concentrations. The main objective of this study is to understand the effects of particulate, colloidal, and truly dissolved fractions on the transport and fate of trace metals in acid mine drainage. This study was conducted for the Onjeong creek in the Uljin mine area. Sampling was carried out in 13 sites, spatially covering the area from mine dumps to the downstream Onjeong reservoir. To examine the metal partitioning between particulate, colloidal, and truly dissolved fraction, we used successive filtration techniques consisting of conventional method (using 0.45 $\mu$m membranes) and tangential-flow ultrafiltration (using 0.001 $\mu$mm membranes). Ultrafiltration may seperate much smaller particles from aqueous phase (Josephson, 1984; Hernandez and Stallard, 1988). The analysis of metals were performed by inductively coupled plasma - atomic emission spectrometer (ICP-AES: model Perkin Elmer OPTIMA3000XL). Anions such as SO$_4$, Cl and NO$_3$ were measured with ion chromatograph (IC: model Dionex 120). Sample analysis is still in progress. The preliminary data show that the studied creek is severely polluted by Al, Fe, Mn, Pb and Zn. Toward upstream sites with relatively lower pH, less than 50% of Al and Fe occur in the sorbed form on particles or colloids, whereas more than 80% of Al and Fe occur in the sorbed form in downstream sites or tributaries with relatively higher pH. Less than 30% of Zn is present in particle or colloidal forms in the whole range of creek. Truly dissolved fraction of trace metals is negatively correlated with pH. The Kd values for Al, Fe and Zn consistently increase with increasing pH and decrease with increasing particle concentration.

• The Korean Journal of Ecology
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• v.24 no.1
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• pp.35-43
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• 2001

Accumulation, elimination and subcellular distribution of heavy metals in Littorina brevicula exposed to cadmium and zinc separately and concurrently were investigated. When the winkles had been exposed to 400 ㎍/L CdCl₂ and 3000 ㎍/l ZnSO₄ separately for 90 days, each of the metal body burden in the whole sofl parts increased in proportion to time of exposure until 70 days. But it didn't increase after 70 days. But when the winkles had been exposed to cadmium and zinc simultaneously, cadmium body burden decreased but zinc body burden increased as compared to the winkles exposed to each of the metal. We also found that cadmium accumulated in the winkles was not depurated for 42 days, but zinc accumulated in them was depurated. Especially, zinc was depurated faster when they had been exposed to mixture of cadmium and zinc. After the winkles had been exposed to cadmium and zinc separately for 70 days, about 60% cadmium of the total body burden was associated with the soluble fraction, while about 75% zinc of the total body burden was associated with insoluble fraction. And these trends of metal partitioning did not alter when the winkles had been exposed to metal mixture. After the soluble fraction applied to gel-filtration chromatography column, the distribution patterns of cadmium and zinc associated with proteins or ligands were different each other. Most of cadmium (＞90%) in the soluble fraction was bound to MBP-1 (Metal-binding protein-1), about 6.5 kDa), while zinc was distributed evenly to HMW (High molecular weight fraction, >60 kDa), MBP-1, MBP-2 (about 5 kDa), LMW (Low molecular weight fraction, <1 kDa).