• Journal of the Mineralogical Society of Korea
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• v.29 no.4
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• pp.191-198
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• 2016

Pyromorphite($Pb_{4.85}(P_{1.02}O_4)_3Cl_{1.04}$) which belongs to the apatite group was compressed up to 33.4 GPa for its equation of state at ambient temperature. High pressure experiment was performed with symmetrical diamond anvil cell employing the angle dispersive X-ray diffraction method. Pressure was determined by ruby fluorescence calibration method. No phase transition were observed and bulk modulus was determined to be 80(7) GPa when $K{_0}^{\prime}=13(2)$. Employing the normalized pressure-normalized strain analysis, reliability check of the compressible behavior was conducted.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09b
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• pp.1179-1180
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• 2005

To immobilize the pollutants from wastewater in situ, two phosphatic clays collected from different areas in Egypt (eastern and western Sebaia, Aswan-Isna, Upper Egypt) used to remove contaminant ions from industrial wastewater. Obtained results confirmed the strong relationship between phosphatic clay and Pb elimination from wastewater. The sensitivity classification of phosphatic clay toward ions retained as described in three categories: highly sensitive to retain Pb , Al and Cr ; moderately sensitive for Mn; and weakly sensitive for Band Zn. Data suggested that large fraction of Pb removed by phosphatic clays stayed intact under a wide variation in extracting solution pH (3-11). In situ immobilization is considered a promising technique that has the potential to remove contaminant ions from wastewater. Two important factors need to be considered when applying this technique: The first, is the clay must be effective and selective under different composition of wastewater. The second, is the immobilized ions should be stable and non-leacheable under varying water conditions. Phosphatic clays with $Pb^{2+}$ were suitable to achieve these two factors. Possible mechanism for removal $Pb^{2+}$ by phosphatic clays is the formation of fluoropyromorphite through the dissolution of fluoro and hydroxyl apatite by its precipitation from solution, beside, Pb complexation at phosphatic clay surface at P-OH sites.

• Economic and Environmental Geology
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• v.49 no.6
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• pp.491-504
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• 2016

Jinwon Au-Ag deposit is located in the Uijin gun which is southeast 300 km from Seoul. The deposit area consists of mainly Precambrian Hongjesa granite, which occurs as porphyroblastic texture, medium grain and composed of quartz, feldspar and mica. This deposit consists of four parallel hydrothermal quartz veins that fill NE oriented fractures in Precambrian Hongjesa granite. The grade of quartz veins contain from 3.0 to 21.4 g/t (average 6.4 g/t) gold and from 5.0 to 252.0 g/t (average 117.9 g/t) silver, respectively. They vary from 0.2 m to 0.6 m (average 0.3 m) in thickness and extend to about 200 m in strike length. Quartz veins occur as massive, network, cavity, breccia, crustiform, comb and zonal textures. Wallrock alteration has silicification, sericitization, pyritization and argillitization. The mineralogy of the quartz veins consists of quartz, arsenopyrite, cassiterite, pyrite, sphalerite, chalcopyrite, galena, electrum, tetrahedrite, canfieldite, argentite, Ag-Sb-S mineral, Mn-Fe-O mineral, Pb-O mineral and Pb-P-Cl-O mineral(chloro-pyromorphite). Chemical compositions of minerals from this deposit are as followed; Fe/Fe+Mg of sericite is from 0.32 to 0.71, As content of arsenopyrite ranges from 27.91 to 30.33 atomic %, FeS content of sphalerite range from 9.77 to 16.76 mole %, Ag content of electrum is from 29.42 to 37.41 atomic % and Ag content of tetrahedrite range from 32.17 to 36.53 wt.%, respectively. Baased on mineralogy and chemical compositions of minerals from Jinwon Au-Ag deposit, deposition of minerals was caused by a change in temperature, oxygen fugacity($fO_2$) and sulfur fugacity($fS_2$) from the near neutral hydrothermal fluid evolved by reaction with wallrock.

• Journal of Applied Biological Chemistry
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• v.58 no.1
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• pp.39-50
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• 2015

Stabilization of heavy metals such as Pb, Cd, Zn, and Cu was evaluated in contaminated soil treated with poultry manure (PM) as well as its biochars pyrolyzed at $300^{\circ}C$ (PBC300) and $700^{\circ}C$ (PBC700) at the application rates of 2.5, 5.0, and 10.0 wt% along with the control, prior to 21-days incubation. After incubation, soil pH was increased from 6.94 (control) to 7.51, 7.24, and 7.88 in soils treated with PM 10 wt%, PBC300 10 wt%, and PBC700 10 wt% treatments, respectively, mainly due to alkalinity of treatments. In the soil treated with PM, the concentrations of the toxicity characteristic leaching procedure (TCLP)-extractable Pb, Cd, Zn, and Cu were increased by up to 408, 77, 24, and 955%, respectively, compared to the control. These increases may possibly be associated with an increased dissolved organic carbon concentration by the PM addition. However, in the soil treated with PBC700, TCLP-extractable Pb, Cd, Zn, and Cu concentrations were reduced by up to 23, 38, 52, and 36%, respectively, compared to the control. Thermodynamic modelling using the visual MINTEQ was done to predict the precipitations of $Pb(OH)_2$, $Cu(OH)_2$ and P-containing minerals, such as chloropyromorphite [$Pb_5(PO_4)_3Cl$] and hydroxypyromorphite [$Pb_5(PO_4)_3OH$], in the PBC700 10 wt% treated soil. The SEM-elemental dot mapping analysis further confirmed the presence of Pb-phosphate species via dot mapping of PBC700 treated soil. These results indicate that the reduction of Pb concentration in the PBC700 treated soil is related to the formations of chloropyromorphite and hydroxypyromorphite which have very low solubility.