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      Permanent link:
      https://www.ias.ac.in/article/fulltext/boms/041/01/0006

    • Keywords

       

      Carbon nanotubes; surface modification; lead ions removal; surface-modified carbon nanotubes.

    • Abstract

       

      Surface-modified carbon nanotubes (CNTs) were prepared in order to remove lead ions (Pb$^{2+}$) from aqueoussolution. The modification of CNTs was conducted by oxidation, using a mixture of nitric acid (HNO$_3$) and sulphuric acid(H$_2$SO$_4$). The adsorption behaviour was well fitted to the Langmuir model and the maximum adsorption capacity of Pb$^{2+}$ was found to be 100 mg g$^{−1}$. The adsorption of Pb$^{2+}$ reached equilibrium in 80 min. The experimental data were well fitted to a pseudo-second-order rate model rather than a pseudo-first-order model. The activation energy and activation enthalpy of the adsorption calculated from Arrhenius and Eyring equations were, respectively, 21.08 and 18.56 kJ mol$^{−1}$, which reflect the outside surface adsorption and ion exchange mechanism. The thermodynamical studies showed that the adsorption of Pb$^{2+}$ was a spontaneous and endothermic process. The ion exchange mechanism of Pb$^{2+}$ removal was confirmed by the pH and electrical conductivity data in solution before and after adsorption.

    • Author Affiliations

       

      NGUYEN DUC VU QUYEN1 TRAN NGOC TUYEN1 DINH QUANG KHIEU1 HO VAN MINH HAI1 DANG XUAN TIN1 PHAM THI NGOC LAN2 ITATANI KIYOSHI3

      1. Chemistry Department, College of Sciences, Hue University, Hue City 530000, Vietnam
      2. Transportation Community College, Danang City 550000, Vietnam
      3. Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, Tokyo 102-0094, Japan
    • Dates

       

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