Mine Reclamation Corporation MIRECO

South Korea

Mine Reclamation Corporation MIRECO

South Korea
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Ko M.-S.,Gwangju Institute of Science and Technology | Park H.-S.,Mine Reclamation Corporation MIRECO | Kim K.-W.,Gwangju Institute of Science and Technology | Lee J.-U.,Chonnam National University
Environmental Geochemistry and Health | Year: 2013

Bioleaching of As from the soil in an abandoned Ag-Au mine was carried out using Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. A. ferrooxidans is an iron oxidizer and A. thiooxidans is a sulfur oxidizer. These two microbes are acidophilic and chemoautotrophic microbes. Soil samples were collected from the Myoungbong and Songcheon mines. The main contaminant of the soil was As, with an average concentration of 4,624 mg/kg at Myoungbong and 5,590 mg/kg at Songcheon. A. ferrooxidans and A. thiooxidans generated lower pH conditions during their metabolism process. The bioleaching of As from soil has a higher removal efficiency than chemical leaching. A. ferrooxidans could remove 70 % of the As from the Myoungbong and Songcheon soils; however, A. thiooxidans extracted only 40 % of the As from the Myoungbong soil. This study shows that bioleaching is an effective process for As removal from soil. © 2013 Springer Science+Business Media Dordrecht.


Lee S.H.,Gwangju Institute of Science and Technology | Kim J.-Y.,Gwangju Institute of Science and Technology | Kim H.A.,Gwangju Institute of Science and Technology | Kim K.-W.,Gwangju Institute of Science and Technology | And 4 more authors.
Understanding the Geological and Medical Interface of Arsenic, As 2012 - 4th International Congress: Arsenic in the Environment | Year: 2012

In order to remove arsenic, adsorption methods are widely used because of its cost-effectiveness and installation convenience. In this study, yttrium based adsorbents such as yttrium carbonate, yttrium hydroxide and titanium-loaded yttrium carbonate are tested to develop highly selective adsorbent for the removal of arsenic. Yttrium hydroxide showed the best removal efficiency on arsenite removal whereas Ti-loaded yttrium carbonate showed the best removal efficiency on arsenate removal because of enhanced surface area. These results suggested that yttrium based materials could be effective adsorbents for arsenic removal from water. © 2012 Taylor & Francis Group.


Kim D.-M.,Korea University | Kim D.-M.,Mine Reclamation Corporation MIRECO | Yun S.-T.,Korea University | Yun S.-T.,University of Calgary | And 3 more authors.
Chemical Geology | Year: 2014

A shallow (<25m), coastal alluvial groundwater system underneath a paddy field in the Yangyang area of South Korea was investigated to examine the occurrence of redox processes. The aquifer is affected by seawater intrusion, and is characterized by a highly reducing environment facilitated by high organic matter in the sediments. Hydrochemical data with δ34S and δ18O of sulfate were examined for depth-specific groundwater from two multilevel samplers that were installed at seaward (YY2) and landward (YY1) locations. Shallow groundwater showed distinct patterns of redox zoning. Evidence of significant bacterial sulfate reduction (BSR) was observed throughout the nearly entire depths of the two boreholes, while at the depths of active seawater intrusion in YY2, conditions suitable for methanogenesis were never reached. Thus, at YY2 the deep zone of intense BSR was overlain by a zone in which methanogenesis occurred in a low-sulfate environment. In contrast, concurrent BSR and methanogenesis in YY1 occurred at depths with high sedimentary organic matter and low dissolved sulfate due to intensive BSR. Considerable BSR in the groundwater representing trapped seawater in a clay layer had resulted in a very strong increase of δ34Ssulfate up to 99.9‰. The inferred sulfur isotopic enrichment factor (ε) for BSR in the lower part of YY2 was -12.3‰, while ε at YY1 was much higher (-45.9‰). In addition, the observed trends of δ18Osulfate at YY1 indicated significant oxygen isotope exchange of sulfate-oxygen with ambient water, likely because of lower cell-specific rates of BSR and higher sulfur isotope fractionation as indicated by the δ34S. In contrast, there was little evidence of oxygen isotope exchange between water and SO4 2- at YY2. This study indicates that in coastal aquifers with sulfate-reducing activity, δ34S and δ18O of sulfate can reveal zones of active seawater intrusion and of trapped seawater. This study provides an example of the application of sulfur and oxygen isotope data with hydrochemical and hydrogeologic data to interpret complex redox zonation in an organic-rich coastal environment. © 2014 Elsevier B.V.


Ko M.-S.,Gwangju Institute of Science and Technology | Kim J.-Y.,Gwangju Institute of Science and Technology | Bang S.,Gwangju Institute of Science and Technology | Lee J.-S.,Mine Reclamation Corporation MIRECO | And 2 more authors.
Environmental Geochemistry and Health | Year: 2012

The stabilization efficiencies of arsenic (As) in contaminated soil were evaluated using various additives such as limestone, steel mill slag, granular ferric hydroxide (GFH), and mine sludge collected from an acid mine drainage treatment system. The soil samples were collected from the Chungyang area, where abandoned Au-Ag mines are located. Toxicity characteristic leaching procedure, synthetic precipitation leaching procedure, sequential extraction analysis, aqua regia digestion, cation exchange capacity, loss on ignition, and particle size distribution were conducted to assess the physical and chemical characteristics of highly arsenic-contaminated soils. The total concentrations of arsenic in the Chungyang area soil ranged up to 145 mg/kg. After the stabilization tests, the removal percentages of dissolved As(III) and As(V) were found to differ from the additives employed. Approximately 80 and 40% of the As(V) and As(III), respectively, were removed with the use of steel mill slag. The addition of limestone had a lesser effect on the removal of arsenic from solution. However, more than 99% of arsenic was removed from solution within 24 h when using GFH and mine sludge, with similar results observed when the contaminated soils were stabilized using GFH and mine sludge. These results suggested that GFH and mine sludge may play a significant role on the arsenic stabilization. Moreover, this result showed that mine sludge can be used as a suitable additive for the stabilization of arsenic. © 2011 Springer Science+Business Media B.V.


Ko M.-S.,Korea Institute of Science and Technology | Kim J.-Y.,Gwangju Institute of Science and Technology | Park H.-S.,Mine Reclamation Corporation MIRECO | Kim K.-W.,Gwangju Institute of Science and Technology
Journal of Cleaner Production | Year: 2015

Arsenic (As) immobilization in soil using acid mine drainage sludge (AMDS) is described following batch, column, and field experiments. The AMDS is a by-product from electrochemical treatment of acid mine drainage and mainly contains Fe-oxide. Batch experiments were carried out to determine optimum mixing ratio of AMDS for As immobilization. Continuous flow column experiments were carried out to identify the optimal excavation method and field experiments were used to assess As immobilization efficiency and feasibility. In the batch experiments, the optimum mixing ratio was determined to be 3.0 wt%. Column experiments indicated that the surface soil amendment was adequate for As immobilization. In the field experiments, the average As concentration in pore water was observed to be 4.9 μg L-1 at the immobilization layer, and 11.6 μg L-1 at the contaminated layer in the AMDS amended plot. In addition, rice grain contained 0.06 mg kg-1 of As. The XANES analysis confirmed that As(V) was the main species in the soil and rice grain. These results indicated that soil amendment with AMDS could induce As immobilization in soil, and prevent As transfer from soil to pore water and crops. © 2015 Elsevier Ltd. All rights reserved.


Kim K.R.,Gwangju Institute of Science and Technology | Ko M.-S.,Gwangju Institute of Science and Technology | Kim J.-Y.,Gwangju Institute of Science and Technology | Lee A.,Gwangju Institute of Science and Technology | And 4 more authors.
Understanding the Geological and Medical Interface of Arsenic, As 2012 - 4th International Congress: Arsenic in the Environment | Year: 2012

Mine sludge was applied for arsenic adsorption from mine drainage. Two different types of reactors were designed for column testing and field application. The results of the column tests showed that the stepwise flow design is better than the upflow design to adsorb arsenic after 600 bed volumes of mine drainage were passed through the reactors. Monitoring results of field application indicate that two types of design have high arsenic removal efficiency (more than 89%), but the stepwise flow design showed slightly higher results than the upflow design. © 2012 Taylor & Francis Group.


Ko M.-S.,Gwangju Institute of Science and Technology | Kim J.-Y.,Gwangju Institute of Science and Technology | Lee J.-S.,Mine Reclamation Corporation MIRECO | Ko J.-I.,Mine Reclamation Corporation MIRECO | Kim K.-W.,Gwangju Institute of Science and Technology
Applied Geochemistry | Year: 2013

Adsorption onto Fe-containing minerals is a well-known remediation method for As-contaminated water and soil. In this study, the use of acid mine drainage sludge (AMDS) to adsorb As was investigated. AMDS is composed of amorphous particles and so has a large surface area (251.2m2g-1). Here, adsorption of both arsenite and arsenate was found to be almost 100%, under various initial AMDS dosages, with the arsenate adsorption rate being faster. The optimum pH for As adsorption onto AMDS was pH 7.0 and the maximum adsorption capacities for arsenite and arsenate were 58.5mgg-1 and 19.7mgg-1 AMDS, respectively. In addition, experiments revealed that AMDS dosages decreased As release from contaminated soil. Therefore, the AMDS used in this study was confirmed to be a suitable candidate for immobilizing both arsenite and arsenate in contaminated soils. © 2013 Elsevier Ltd.


Kwon J.C.,Sejong University | Lee J.-S.,Mine Reclamation Corporation MIRECO | Jung M.C.,Sejong University
Applied Geochemistry | Year: 2012

A national-scale survey of the environment in and around mines was conducted to evaluate the status of total As contamination in agricultural soils surrounding numerous abandoned metal mines in Korea. This survey aimed to compare As concentrations in soils in relation to geology and mineralization types of mines. A total of 16,386 surface soil (0-15cm in depth) samples were taken from agricultural lands near 343 abandoned mines (within 2km of each mine). These samples were decomposed by aqua regia and analyzed for As by AAS with a hydride-generation (HG) device. To compare As levels in soils meaningfully with geology and mineralization types, three sub-classification criteria were adapted: (1) five mineralization types, (2) four valuable ore mineral types, and (3) four parent rock types. The average concentration of As in all the soils was 11.6mgkg -1 with a range of 0.01-4230mgkg -1. Based on the mineralization types, average As concentrations (mgkg -1) in the soils decreased in the order of pegmatite (18.2)>hydrothermal replacement (14.5)>sedimentary deposits (12.4)>hydrothermal vein (10.7)>skarn (4.08). In terms of the valuable ore mineral types, the concentrations decreased in the order of Sn, W, Mo, Fe and Mn mines>Au, Ag, and base metal mines>Au and Ag mines≈base metal mines. For parent rock types, soils from metamorphic rocks and heterogeneous rocks exhibited enhanced As levels related to both igneous and sedimentary rocks. Therefore, it can be concluded that soils from highly altered rocks subject to metamorphic and igneous activities contained relatively high concentrations of As in the surface environment. © 2011 Elsevier Ltd.


Ko M.-S.,Korea Advanced Institute of Science and Technology | Kim J.-Y.,Korea Advanced Institute of Science and Technology | Park H.-S.,Mine Reclamation Corporation MIRECO | Kim K.-W.,Korea Advanced Institute of Science and Technology
Journal of Cleaner Production | Year: 2015

Arsenic (As) immobilization in soil using acid mine drainage sludge (AMDS) is described following batch, column, and field experiments. The AMDS is a by-product from electrochemical treatment of acid mine drainage and mainly contains Fe-oxide. Batch experiments were carried out to determine optimum mixing ratio of AMDS for As immobilization. Continuous flow column experiments were carried out to identify the optimal excavation method and field experiments were used to assess As immobilization efficiency and feasibility. In the batch experiments, the optimum mixing ratio was determined to be 3.0wt%. Column experiments indicated that the surface soil amendment was adequate for As immobilization. In the field experiments, the average As concentration in pore water was observed to be 4.9μgL-1 at the immobilization layer, and 11.6μgL-1 at the contaminated layer in the AMDS amended plot. In addition, rice grain contained 0.06mgkg-1 of As. The XANES analysis confirmed that As(V) was the main species in the soil and rice grain. These results indicated that soil amendment with AMDS could induce As immobilization in soil, and prevent As transfer from soil to pore water and crops. © 2015 Elsevier Ltd.

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