• Proceedings of the Korean Geotechical Society Conference
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.1225-1230
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• 2010

본 연구는 군부대 사격장의 중금속 오염토양에 대하여 생물학적 용출기술(BT)과 전기동력학적 기술(ET)의 통합공정의 적용성 평가 연구에 대한 것이다. 사격장 오염 토양의 경우 사격에 의해 탄두가 피탄지에 박히면서 오염토양 내에 잔존하여 탄두를 구성하는 주성분인 납과 구리 등에 의해 지속적인 오염원으로 작용하는 특징을 가진다. 따라서 사격장 토양오염정화를 위해서는 이 탄두를 물리적으로 선별하는 물리적 선별공정을 전처리공정으로 수행한 후 인공적으로 조성된 셀에 통합공정 적용성 평가를 위한 현장실증시험을 수행하였다. 생물학적 용출을 통해 토양내 잔류하는 중금속을 이온화시켜 이동성을 크게 한후 전기동력학적 기술을 통해 토양내에서 전해질로 이동시켜 최종적으로 전해질을 처리하는 시스템으로써 공정 모니터링결과 납과 구리 모두 주목할 만한 제거효율을 얻을수 있었다. 오염물질별 공정 적용성 평가결과 납의 경우 황산화박테리아에 의해 이온화가 되지만 황산화박테리아의 생장 부산물인 황산염이온(${SO_4}^{2-}$)과 반응하여 안정성이 큰 Anglesite($PbSO_4 $)를 형성하므로 전체적인 제거효율이 저하되는 것을 확인하였고 기타 미생물을 이용한 생물학적 용출기술 연구의 필요성을 확인하였다. 구리의 경우 황산염박테리아를 이용한 생물학적 용출공정 및 전기동력학적 처리공정의 통합공정을 통해 주목할 만한 제거효율을 얻을수 있었으며 통합공정의 효율성을 확인할 수 있었다. 본 연구를 통하여 미생물학적 용출기술과 전기동력학적 기술의 통합공정은 현장특이성(Site-specific) 확인후 적용가능성이 있음을 확인하였다.

• Journal of the Korean Chemical Society
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• 제13권4호
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• pp.313-316
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• 1969

In this paper a simple and rapid method is described for the determination of lead in monazite. A monazite sample was dissolved with hot concentrated sulfuric acid and diluted to 200 ml with distilled water. Lead is quatitatively separated by coprecipitating with strontium. Lead-strontium sulfate is dissolved in 3N NaOH soluion. An excess Zn-EDTA is added. The remaining zinc ion is titrated with standard 0.01 M EDTA solution using xylenol orange as indicator at pH 5 in the presence of KCN and acetyl acetone as masking agents.

• Journal of Korean Society of Environmental Engineers
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• 제32권2호
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• pp.149-154
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• 2010

The feasibility of lead removal by electrolytic coprecipitation was investigated. Electrolysis bath was divided into anode and cathode chamber with anion exchange resin filled membrane. Sea water was electrolyzed and pH of the electrolyte in cathode chamber was increased. Consequently it induced the formation of $Mg(OH)_2$ and $CaCO_3$. The colloidal type precipitates, hich have high surface area, adsorbed lead ions in sea water and coprecipitated. Sea water electrolyses were conducted at different current density. Concentrations of Mg, Ca and Pb in the solution were measured with titration and ASV method. Morphology and crystallography were analyzed with SEM, EDS and XRD. As pH and current density increased, most of lead ions in the sea water were successfully removed.

• Journal of Soil and Groundwater Environment
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• 제6권4호
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• pp.41-50
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• 2001

The use of clay has been the favored method of reducing or eliminating hazardous contaminants in the leachate from landfills. But, neither natural clays nor organoclays modified with surfactants are able to effectively sorb both heavy metals and organic contaminants. Therefore, the objective of this study is to determine the optimal amount of surfactant added on the clay mineral to effectively remove both of them. For this purpose, Na-Bentonite as the natural clay, and hexadecyltrimethylammonium (HDTMA) as the cationic surfactant were used, Chlorobenzene and lead ($Pb^{2-}$) were selected as representative contaminants. Experimental result showed that chlorobenzene sorption increased with increasing HDTMA to bentonite, ratios. On the contrary, the removal rate of lead decreased as the amount of HDTMA increased. The removal of chlorobenzene was influenced by the amount of HDTMA added to the bentonites rather than initial concentration of chlorobenzene, but the removal of lead was much more influenced by the initial concentration of lead. The adsorption of lead was not affected by chlorobenzene, and vice versa. The competitive sorption between the heavy metal and the organic contaminant was not present.

• The Journal of the Petrological Society of Korea
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• 제10권3호
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• pp.133-147
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• 2001

Recently developing method of age determination using stepwise dissolution technique to expand the applicability of absolute age determination significantly is evaluated whether it is applicable to the Korean samples. The materials selected for the study are uranium-bearing black slates from Changni Formation of Ogcheon metamorphic belt, tourmaline separated from Naedeongni granite of Yeongnam massif, garnet and ilmenite separated from ilmenite-bearing anorthositic rock of Yeongnam massif, scheelites from Ogbang mine, and magnetite separated from Gyemyeongsan Formation of Ogcheon metamorphic belt. For the stepwise dissolution, various acid steps with different normalities and different durations were applied to leach the samples. The leachate from each step was analyzed to determine the Pb isotopic composition and concentrations of Pb and U using thermal ionization mass spectrometer. The black slates from the Changni Formation and the tourmaline from the Naedeongni granite reveal significant variation of Pb isotopic composition, which reveals the potential of such stepwise dissolution technique as a dating method. The behaviors of uranium and lead during the each stage of step leaching are different, which seem to reflect the differences in positions within the crystal lattices depending upon mineral species.

• Korean Journal of Materials Research
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• 제4권5호
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• pp.541-549
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• 1994

The crystallization behavior and structural change of amorphous $PbTiO_{3}$ precursors prepared by coprecipitation method were investigated by XRD, Raman spectra, TEM, and RDF. The precursors were prepared at $45^{\circ}C$ and pH of 9 from a mixed solution of lead nitrate and titanium tetrachloride derived using $H_2O_2$ or $NH_4NO_3$ as an ion stabilizer. The activation energy and temperature for crystallization of the coprecipitate prepared using $NH_4NO_3$ as an ion stabilizer were lower than that derived from the solution containing $H_2O_2$ stabilizer. The amorphous coprecipitate transformed to transient phase and then to crystalline $PbTiO_{3}$. Average interatomic distances of amorphous states decreased with increasing heat-treatment temperature.

• KSCE Journal of Civil and Environmental Engineering Research
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• 제26권1C호
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• pp.1-8
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• 2006

The purpose of this study is to experimentally analysis the eletrokinetic phenomena and remediation characteristics developed during the application of electrokinetic remediation technique to unsaturated soils contaminated by heavy metals. In the laboratory a series of column tests are performed on degree of saturation for shooting range soil. The test results indicated that Pb is mainly removed under unsaturated conditions by electromigration within diffuse double layer, and if the initial containment concentration is below cation exchange capacity and equals to adsorption per unit soil solid weight, the remedial efficiency decreases with the decreasing of transport efficiency due to the changes in the degree of saturation in the electric gradient of 1V/cm.

• Composites Research
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• 제32권6호
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• pp.335-341
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• 2019

In this study, an acrylic acid (AAc) was grafted on a polypropylene (PP) nonwoven fabric using electron beam irradiation. Electron beam grafting was carried out under various conditions to produce AAc grafted PP (PP-g-AAc) nonwoven fabric having a grafting yield of about 50% at radiation dose of 100 kGy and a monomer concentration of 60%. The physical and chemical properties of PP-g-AAc nonwoven fabric were evaluated by SEM, ATR-FTIR, thermal analysis and tensile strength. The morphology of PP and PP-g-AAc nonwoven fabric confirmed by SEM showed no significant change, and it was judged that AAc was introduced into PP nonwoven fabric from ATR-FTIR. PP-g-AAc nonwoven fabric showed an increase in tensile strength and a decrease in tensile strain compared to PP nonwoven fabric. However, since change of value is not significant, it is considered that there is no significant influence on the physical characterization. Adsorption experiments of PP-g-AAc nonwoven fabric on various ions showed selective adsorption behavior for lead ion. In conclusion, the electron beam radiation-induced PP-g-AAc nonwoven fabric is expected to be applied as an effective adsorbent for the adsorption of lead ions.

• Korean Journal of Microbiology
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• 제38권1호
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• pp.26-30
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• 2002

A ubiquitous bacterium,Effects of Lead, Copper and Cadmium on Pseudomonas cepacia KH410 Isolated from Freshwater Plant Root was isolated from freshwater plant root and interactions of lead, copper and cadmium with this strain was studied. Mass production of dry cell weight 2.72 g-DCW/ι-medium was obtained by cultivation in a nutrient medium containing 1% yeast extract, 1% soytone and 0.5% NaCl, pH 7.0, at temperature of 28℃ for 24 hrs under aeration. The mass of dry cell produced after exposure with 100 mg/ι of heavy metal was 1.98 g/ι for lead, 1.58 g/ι for copper and 0.20 g/ι for cadmium, respectively. The minimal inhibitory concentrations (MIC) for each heavy metal was 1.3 mM for lead,0.8 mM for copper and 0.4 mM fur cadmium, respectively. Cell aggregation occurred by each heavy metal exposure was observed from 1 day to 4 days by an optical microscope. Entrapment, precipitation effects on cell by heavy metals between 10 min and two hours were examined by an electron microscopy. Cadmium appeared to be the most toxic on cells and the order of toxicity was cadmium>copper>lead.

• Journal of Conservation Science
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• 제30권4호
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• pp.345-351
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• 2014

Chemical and Pb isotope analysis were performed in order to determine the origin of bronze artefacts excavated from the Inyongsaji site in South Korea. The result of ICP-MS shows that they are tin bronzes in which lead was not intentionally added during production. Pb isotope data analyzed by TIMS are plotted in the southern region of Korea and China of the distribution map drawn by Mabuchi(1985). On the other hand, the identical isotope data are plotted in the Taebaek basin and the Olcheon metamorphic belt correspondent to zone2 and zone3 respectively. It is believed that the isotope data on the tin bronzes which have very low lead content can be used to trace the origin of copper ore rather than those of either lead or tin ore. Pb istope analysis allows diverse interpretation as it can be applied to any object containing trace amounts of lead. In addition, accumulation of isotope data as well as further studies will improve reliability of the provenance studies.