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Nguyen V.K.,Chonnam National University | Tran T.,Chonnam National University | Han H.-J.,Chonnam National University | Lee S.-H.,Korea Mine Reclamation Corporation | Lee J.-U.,Chonnam National University
Journal of Geochemical Exploration | Year: 2015

There is an environmental risk of Sb becoming a major pollutant due to the quick increase in the production of Sb industry. However, there have been few investigations on interactions between Sb and microorganisms and bioremediation of Sb this paper presents an investigation on bioleaching of Sb from contaminated sediment which is collected in the vicinity of a Sb processing plant using the iron-oxidizer, Acidithiobacillus ferrooxidans. The bioleaching of Cr, Cu, Mn, Ni, and Zn in the sediment was also investigated to compare with that of sb. Duplicated batch-type experiments based on different incubation time, on the presence or absence of Fe2+ and/ or Ag+, were conducted to compare the efficiency of metal extraction. After bioleaching, 97.4% of Ni, 95.2% of Mn, 65.8% of Cr, 36.2% of Cu, 34.8% of Zn, and 2.2% of Sb were extracted from sediments. The extraction efficiency of Sb was the lowest in comparison to those of Cr, Cu, Mn, Ni, and Zn. This result indicated that Sb is difficult to solubilize by bacterial leaching. The catalytic effect of Ag+ was not observed, which could be due to the inhibition of Ag+ on the activity of A. ferrooxidans and formation of Ag jarosite precipitation on the surface of sediment particles. Though the extraction of Sb was not efficient, this study demonstrates the potential for Sb to be bioleached and a feasible technique in remediation of Sb. © 2015 Elsevier B.V. Source


Cui M.,Korea University | Jang M.,Korea Mine Reclamation Corporation | Cho S.-H.,Korea University | Khim J.,Korea University
Environmental Technology | Year: 2010

In this study, we investigated the application of sludge waste obtained from a coal mine drainage treatment facility that treats acid mine drainage (designated as AMD) from metal-mine water. The coal mine drainage sludge (designated as CMDS), which contained 70% goethite and 30% calcite, was utilized as a sorption material for Cu(II) and Zn(II) removal from an aqueous solution of metallic mine drainage. The equilibriums and kinetics were investigated during a series of batch adsorption experiments. The Langmuir model was used to fit the equilibrium data, resulting in the best fits. The removal efficiencies were controlled by solution pH, temperature, initial concentration of heavy metal, sorbent amount and contact time. The pseudo-second-order kinetic model was used to fit the kinetic data, providing a good correlation with the experimental data. The results of a thermodynamic study showed that the activation energies (EA) were 3.75 and 1.75 kJ mol-1 for the adsorption of Cu(II) and Zn(II) on to CMDS at pH 5.5. These values of activation energy could correspond to physisorption. The positive values obtained for both the standard enthalpy change, Δ0, and the standard entropy change, ΔS0, suggest that the adsorption of Cu(II) and Zn(II) on to the CMDS was an endothermic reaction and that randomness increased at the solid-liquid interface during the adsorption of Cu(II) and Zn(II) on to the CMDS. The adsorption process also followed a pseudo-second-order kinetic model. © 2010 Taylor & Francis. Source


Nguyen V.K.,Chonnam National University | Nguyen V.K.,Pusan National University | Tran T.,Chonnam National University | Han H.-J.,Chonnam National University | And 2 more authors.
Journal of Geochemical Exploration | Year: 2015

There is an environmental risk of Sb becoming a major pollutant due to the quick increase in the production of Sb industry. However, there have been few investigations on interactions between Sb and microorganisms and bioremediation of Sb this paper presents an investigation on bioleaching of Sb from contaminated sediment which is collected in the vicinity of a Sb processing plant using the iron-oxidizer, Acidithiobacillus ferrooxidans. The bioleaching of Cr, Cu, Mn, Ni, and Zn in the sediment was also investigated to compare with that of sb. Duplicated batch-type experiments based on different incubation time, on the presence or absence of Fe2+ and/ or Ag+, were conducted to compare the efficiency of metal extraction. After bioleaching, 97.4% of Ni, 95.2% of Mn, 65.8% of Cr, 36.2% of Cu, 34.8% of Zn, and 2.2% of Sb were extracted from sediments. The extraction efficiency of Sb was the lowest in comparison to those of Cr, Cu, Mn, Ni, and Zn. This result indicated that Sb is difficult to solubilize by bacterial leaching. The catalytic effect of Ag+ was not observed, which could be due to the inhibition of Ag+ on the activity of A. ferrooxidans and formation of Ag jarosite precipitation on the surface of sediment particles. Though the extraction of Sb was not efficient, this study demonstrates the potential for Sb to be bioleached and a feasible technique in remediation of Sb. © 2015 Elsevier B.V. Source


Cui M.,Korea University | Jang M.,Korea Mine Reclamation Corporation | Cho S.-H.,Korea University | Elena D.,Romanian Institute of Isotopic And Molecular Technology | Khim J.,Korea University
Ultrasonics Sonochemistry | Year: 2011

As an advanced oxidation process, the combination of sonolysis (US)/ozonolysis (O3) was investigated on the treatment of tannic acid (TA) and humic acid (HA). In this study, biodegradable chemicals were found by the molecular weight and GC-MS analysis method, and mineralization rate and synergetic effects were also studied. For the water samples prior to the treatment of US/O3, ratios of molecular size higher than 5000 and 2000 Da for HA and TA, detected by the ultra filtration method, were 90.25% and 89.53%, respectively. However, after 0.5 h of reacting, this ratio rapidly reduced to 3% and 4%, and the ratios of molecules for HA and TA less than 500 Da rapidly increased from 0.8% to 41% and from 0.65% to 39%, respectively. In the results of chemical oxygen demand (CODCr) and total organic carbon (TOC) reductions, the US/O3 process also showed synergetic effect by US/O3 for CODCr of HA and TA were 19% and 11%, and those for TOC of HA and TA were 0% and 1%, respectively. The major by-products of the oxidation process included formaldehyde, acetone, hydroxylamine, etc. Biological decomposable materials could be indirectly inferred by measuring the molecular weights and intermediates. © 2010 Elsevier B.V. Source


Cui M.,Korea University | Jang M.,Korea Mine Reclamation Corporation | Cho S.-H.,Korea University | Khim J.,Korea University
Environmental Geochemistry and Health | Year: 2011

Various analyses of physico-chemical characteristics and batch tests were conducted with the sludge obtained from a full-scale electrolysis facility for treating coal mine drainage in order to find the applicability of sludge as a material for removing Zn(II) in an aqueous phase. The physico-chemical analysis results indicated that coal mine drainage sludge (CMDS) had a high specific surface area and also satisfied the standard of toxicity characteristic leaching procedure (TCLP) because the extracted concentrations of certain toxic elements such as Pb, Cu, As, Hg, Zn, and Ni were much less than their regulatory limits. The results of X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) showed that the CMDS mainly consists of goethite (70%) and calcite (30%) as a weight basis. However, the zeta potential analysis represented that the CMDS had a lower isoelectric point of pH (pHIEP) than that of goethite or calcite. This might have been caused by the complexation of negatively charged anions, especially sulfate, which usually exists with a high concentration in coal mine drainage. The results of Fourier transform infrared (FT-IR) spectrometry analysis revealed that Zn(II) was dominantly removed as a form of precipitation by calcite, such as smithsonite [ZnCO3] or hydrozincite [Zn5(CO3)2(OH)6]. Recycling sludge, originally a waste material, for the removal process of Zn(II), as well as other heavy metals, could be beneficial due to its high and speedy removal capability and low economic costs. © 2010 Springer Science+Business Media B.V. Source

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