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        검색결과 1,677

        1507.
        2003.04 KCI 등재 서비스 종료(열람 제한)
        The new tridentate ligands of nitrogen doner atoms N,N-Bis(2-amino-ethyl)-benzyl-amine·2HCl(BABEA·2HCl) and 2,6-Bis(amino-methyl)-pyridien·2HCl(BAMP·2HCl) were synthesized as their dihydrochloride salts and characterized by EA, IR, Mass and NMR spectroscopy. The protonation constants of the ligands and stability constants for Cd2+, Pb2+, Zn2+and Cu2+ ions were determined by potentiometric titration in aqueous solutions and compared with those of analogous ligands. The effect stability constants of ligands and metal ions for removal of heavy metals in aqueous solution were described.
        1510.
        2002.12 KCI 등재 서비스 종료(열람 제한)
        Thirty sediment samples of the <63㎛ fraction collected from the southwestern coast of Korea were analysed for their heavy metal (Fe, Mn, Cr, Co, Cu, Ni, Zn and Pb) concentration. The results show that sediment texture plays a controlling role on the total metal concentrations and their spatial distribution. A single 1M HCl extraction procedure was used in order to assess the environmental risk of heavy metals in bottom sediments. The non-residual fraction was the most abundant pool for Mn and Pb in most samples, which means that this metals are highly avaliable in these sediments. Cr, Ni, Fe, Co, Zn and Cu were mainly associated with the residual fraction, suggesting that their concentrations are controlled significantly by transport processes with the fine particles as carriers from diffuse pollution source. Concentration enrichment ratios(CER) were calculated from the non-residual contents and their values allowed us to classify the sediments according to their environmental risk.
        1511.
        2002.12 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to determine the contents of heavy metals in leaves of roadside trees according to different growth stages in Daegu city. The orders of heavy metal contents in leaves of roadside tree and soil were Fe>Mn>Zn>Pb>Cu>Cr>Cd and Fe>Mn>Zn>Cu>Pb>Cr>Cd, respectively. The contents of heavy metals in leaves of roadside trees and soil showed an increasing tendency as the levels of traffic volume increased. The contents of heavy metals in leaves on October were higher than those on May. Zelkova serrata and Ginkgo biloba showed high contents of Cr, Cd and Pb.
        1520.
        2002.09 KCI 등재 서비스 종료(열람 제한)
        Waste paper cup was sulfonated to be used as ion exchanger. Removal characteristic of copper and lead ion by prepared ion exchanger was investigated. The sulfonation was conformed by the high intensity band of SO3H group around 1100~1160cm-1. The synthesized ion exchanger had greater removal ability for copper and lead ion than the original waste paper cup. Ion exchange system reached the final equilibrium plateau within 30min. The maximum removal capacities (qmax) were calculated as 9.79mg/g for copper and 15.95mg/g for lead, respectively. The affinity of lead based on a weight was higher than that of copper. The ion exchange phenomena appeared to follow a typical Freundlich isotherm.