Preparation and characterization of functionalized MWCNTs-COOH with 3-amino-5-phenylpyrazole as an adsorbent and optimization study using central composite design

摘要: Carboxylated multi-wall carbon nanotubes (MWCNTs-COOH) was functionalized with 3-amino-5-phenylpyrazole (MWCNTs-f) and characterized by FTIR, EDX, SEM, XRD TGA. The MWCNTs-COOH MWCNTs-f were used for the adsorption of Cd(II), Hg(II), As(III) ions from aqueous solutions. Additionally, to study influence pH, adsorbent dose, initial concentration on process, central composite design (CCD) applied. quadratic model analysis variance indicated that metal strongly depends pH. Time-dependent can be described pseudo-second-order kinetic model, process modeled Langmuir isotherm adsorbents. Thermodynamic showed Hg(II) spontaneous endothermic. Moreover, competitive capacities heavy slightly lower than noncompetitive ones. same affinity order observed under adsorption: As(III) > Cd(II) > Hg(II) in case MWCNTs-f. Desorption revealed favorable regeneration ability adsorbents powders, even after three adsorption–desorption cycles.