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        검색결과 1,677

        1401.
        2007.08 KCI 등재 서비스 종료(열람 제한)
        Hydrochloride acid salts of new N2O2 tetradentate ligands containing amine and phenol N,N'-bis(2-hydroxybenzyl)-o-phenylenediamine(H-BHP), N,N'-bis(5-bromo-2-hydroxybenzyl)-o-phenylenediamine(Br-BHP), N,N'-bis (5-chloro-2-hydroxybenzyl)-o-phenylene-diamine(Cl-BHP), N,N'-bis(5-methyl-2-hydroxybenzyl)-o-phenylene-diamine (Me-BHP) and N,N'-bis(5-methoxy-2-hydroxybenzyl)-o-phenylenediamine(MeO-BHP) were synthesized. The ligands were characterized by elemental analysis, mass and NMR spectroscopy. The elemental analysis showed that the ligands were isolated as dihydrochloride salt. The potentiometry study revealed that the proton dissociation constants(logKnH) of ligands and stability constants (logKML) of transition and heavy metals complexes. The order of the stability constants of each metal ions for ligands was Br-BHP < Cl-BHP < H-BHP < MeO-BHP < Me-BHP.
        1402.
        2007.06 KCI 등재 서비스 종료(열람 제한)
        The contents of five heavy metals such as lead, cadmium, zinc, copper and manganese in soil and vegetables collected from four sites in Busan district with composite sampling method were determined with ICP emission spectrometer. The ranges of their contents in soil were lead, 1.65~4.36 ppm; cadmium, 0.05~0.09 ppm; zinc, 6.33~11.09 ppm; copper, 0.44~1.35 ppm; manganese, 8.40~19.39 ppm, respectively. These contents were lower than the Clarke number. The range of heavy metal contents in four vegetables such as lettuce, radish and its roots, spinach and cabbage were lead, 0.09~0.48 ppm; cadmium, 0.01~0.08 ppm; zinc, 1.81~14.62 ppm; copper, 0.14~1.87 ppm; manganese, 0.71~14.5 5ppm with the order of Zn(7.30 ppm)>Mn(4.35 ppm)>Cu(0.53 ppm)>Pb(0.19 ppm)>Cd(0.04 ppm) in average contents. The average transfer ratio of metals from soil to vegetables was order of Zn(77.8 %)> Cd(37.5 %)>Cu(34.5 %)>Mn(18.6 %)>Pb(6.7 %). In case of the same cultivating soil, the transfer ratio could be expected to the order of spinach<radish<cabbage<lettuce for copper, lettuce≈cabbage<radish<spinach for manganese, respectively.
        1403.
        2007.06 KCI 등재 서비스 종료(열람 제한)
        Mesoporous silicas for heavy metals adsorption were prepared by co-condensation of surfactant as a template and Ludox HS-40 as a silica precursor. Various mesoporous silicas with the introduction of chelating ligands (mercaptopropyl and aminopropyl groups) were synthesized to remove heavy metal ions from aqueous solutions. The surface modification was conducted with a co-condensation process using the sequential or simultaneous addition of mesoporous silica and high concentration of the organosilane(3-mercaptopropyltrimethoxysilane and 3-aminopropyltriethoxysilane). These materials have been characterized by elemental analysis, XRD, SEM and TEM analysis. Adsorbents synthesized with 3-mercaptopropyltrimethoxysilane and 3-aminopropyltriethoxysilane shows a high loading capacity for Hg(II), Pb(II) , Cd(II) and anion Cr(VI). Especially the one synthesized with a mercaptopropyl function has the highest adsorption capacity for Hg(II) and Cd(II).
        1404.
        2007.06 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 석탄 광산배수에 함유된 중금속을 부유선별로 제거하기에 앞서 부유선별 조건에 영향을 미치는 철, 망간, 알루미늄 이온의 침전특성을 알아보았다. Fe(III), Mn(II), Al(III) 이온을 NaOH와 반응시켜 1 h 동안 침전시키면 Fe(III)은 pH 5.0 이상에서, Mn(II)은 pH 10.0 이상에서 그리고 Al(III)은 pH 6.0~9.0의 범위에서 대부분 침전되어 여액에 1.0mgL-1 이하로 잔류되었다. Fe(III), Mn(II), Al(III)의 혼합 용액에 포수제인 올레인산나트륨을 첨가하였을 경우, 각각의 중금속 이온은 올레인산나트륨과 반응하여 불용성 염을 거의 형성하지 않았기 때문에 침전 부선법으로 광산배수에 함유된 중금속을 제거해야 하는 것으로 나타났다.
        1405.
        2007.05 KCI 등재 서비스 종료(열람 제한)
        The content and distribution of some heavy metals (Fe, Mn, Cr, Co, Cu, Ni, Zn and Pb) were investigated in the <63 ㎛ bed sediments of the Mangyeong river to recognize the extent of contamination. Results showed that a wide range of concentrations was apparent for every metal. These variations were particularly significant at the confluence of tributaries. High levels of metals occur mainly in the confluence of tributaries. Geoaccumulation indexes have been calculated to assess whether the concentration observed represent background or contaminated levels. It is proved that the Mangyeong River is moderately to strongly polluted for Mn, Cr, Cu, Zn and Pb. The spatial extent of pollution was examined, and it was found that the most polluted area is located in the confluence of Iksan and Jeonju tributaries.
        1407.
        2007.02 KCI 등재 서비스 종료(열람 제한)
        We studied concentration of heavy metals in Sagunjatang. In this experiment was analyzed the concentration of heavy metals of boiled Sagunjatang, decoction and its ingredient herbal medicines. The concentration of heavy metals(As, Pb, and Cd) were analysed using ICP-AES, and Hg was analysed by mercury analyzer. The average concentration of heavy metals in Sagunjatang were as follows : In all ingredient herbal medicines (Glycyrrhizae Radix, Atractylodes Macrocephala, Poria Cocos and Jinseng) of Sagunjatang, As(arsenite) contents in all samples was in the range of 0.369-0.723ppm, Cd(cadmium) was in the range of 0.000-0.085ppm, Pb(lead) was in the range of 0.059-0.871ppm and Hg(mercury) was in the range of 0.001-0.004ppm. In boiled Sagunjatang, the concentration of heavy metals(As, Pb, Cd and Hg) was in the range of 0.000-0.016ppm, respectively. In the decoction of herbal medicines after boiled, the concentration of heavy metals was in the range of 0.004-0.387ppm. These results suggest that Sagunjatang which we take is less harmful than herbal medicine itself, and there are more significant for using the decoction of herbal medicines.
        1408.
        2006.12 KCI 등재 서비스 종료(열람 제한)
        Deposited road particles (DRPs) were analysed for heavy metal concentrations at four different roads in a city, Korea. The samples were collected using a roadway surface vacuum cleaning vehicle which was commonly used in collecting roadway surface particles. Six particle size ranges were analyzed separately for twelve heavy metal elements (Cd, Cr, Pb, Ni, Al, As, Co, Cu, Fe, Mn, Zn and Hg). At all sampling sites, the high concentration of the heavy metals occurred in the <74um particle size range, which conventional roadway cleaning vehicles do not remove efficiently. The Pb concentration significantly increased with decreasing particle size of DRPs, and other toxic heavy metals (Cd, Cr and Ni) also showed similar results. The heavy metal concentrations in the smaller size fraction of DRPs is important because they are contaminants that are preferentially transported by road runoff during rainfall.
        1410.
        2006.12 KCI 등재 서비스 종료(열람 제한)
        본 연구는 낙동강의 주요 지류인 금호강에 대하여 하상퇴적물의 광물학적 성분을 밝히고 이와 더불어 퇴적물에 포함된 중금속의 농도를 파악하여 이에 미치는 영향 등을 알아보고자 수행되었다. 금호강의 경우 유하거리가 짧지만 유하하는 동안 암상 및 산업지대의 변화가 뚜렷하여 퇴적물내 중금속의 농도에 영향을 미치는 지질학적 및 산업활동에 의한 요인들을 알아보기에는 좋은 연구대상이다. 하천퇴적물을 이루고 있는 광물로는 석영, 알바이트 사장석 등이 주요 조암광물을 이루고 있었으며 이외 정장석, 미사장석, 각석섬 등이 소량으로 동정되었다. 점토광물로는 일라이트, 녹니석, 카올리나이트 등이 같이 산출되었다. 상류에서 하류로 가면서 화산암에서 퇴적암으로 암상이 변하지만 전체적인 광물의 종이나 양에 있어서는 뚜렷한 변화를 보이지 않고 있어 모암의 영향은 거의 없는 것으로 보인다. 중금속의 경우 함유량에 있어서 Zn > Pb > Cu > Ni > Cr > Co > Cd의 순서로 나타났다. 상류에서 하류로 가면서 시료채취지점별로 농도의 증감을 보이며 Pb를 제외하고는 전체적으로 증가하는 것으로 나타났다. 부분적인 농도의 증가는 오염원으로부터 유출된 중금속을 포함하는 지천의 영향을 주로 받는 것으로 나타났으며 광물의 성분의 변화가 없음에도 이러한 변화를 보이는 것은 대체로 광물의 영향보다는 오염원의 영향이 더 큰 것으로 보인다. Pb와 Ni의 경우를 제외하고는 과거의 오염원에 의하여 현재까지 퇴적물에 부화되어 있는 것으로 판단된다.
        1411.
        2006.12 KCI 등재 서비스 종료(열람 제한)
        이 논문에서는 대전광역시 도심하천인 유등천 및 유등천이 합류된 갑천 하류 하상퇴적물의 물리화학적 특성을 분석하고 중금속에 의한 오염 정도를 평가하였다. 유등천 하천퇴적물은 약산성내지 약알칼리이며, 퇴적물 대부분은 모래가 약 80% 이상인 사질토로 양이온 보유능력과 수분보유 능력이 낮아 식물이 자라기에 부적합한 퇴적물임을 지시한다. 따라서 유등천변 소유역 퇴적물이 토양의 기능중 하나인 자정능력을 갖추기 위해서는 점토를 많이 객토하여 식생과 자정능력을 가지는 소유역 토양으로 전환해야 할 것으로 판단한다. 조사 지점별 중금속 성분의 함량변화 특성을 보면 유등천은 도심을 통과하면서 토사내 중금속(Pb, Cr, Cd)의 농도가 증가되는 경향을 보인다. 이러한 하천유역 토사내중금속 농도의 증가는 하천수의 수질과 관련이 있는 것으로 보인다. 하상퇴적물 깊이별 중금속의 농도는 일부지점에서 심도증가와 함께 증가하는 경향을 보인다. 하천수의 수질오염은 하천 퇴적물의 오염으로 이어지고 이는 궁극적으로 하천생태환경에 영향을 미치게 되므로 하천수의 수질에 대한 지속적인 감시와 오염된 하상퇴적물에 대한 정화작업이 필요하다.
        1413.
        2006.11 KCI 등재 서비스 종료(열람 제한)
        This study was performed to investigate the possible uses of waste sludge for the removal of heavy metal ions. The adsorption experiments were conducted with wastes such as sewage treatment sludge, water treatment sludge and oyster shell to evaluate their sorption characteristics. Heavy metals selected were cadmium, copper and lead. In the sorption experiments on the sewage treatment sludge, water treatment sludge, oyster shell and soil, sorption occurred in the beginning and it reached equilibrium after 40 minutes on the oyster shell and 4 hour on the sewage treatment sludge and water treatment sludge. Results of Freundlich isotherms indicated that sewage treatment sludge could be properly used as an adsorbent for heavy metals and sorption strength of heavy metals was in the order of Pb > Cu > Cd. In the influence of pH on the adsorbents, sorption rate was more than 80% in pH 4 and most of heavy metals were adsorbed in pH 9. Adsorption rate of Cd decreased with decreasing pH and then adsorption rate of Cu was lower in soil.