Synthesis of functionalized nanotube-C60 hybrid and its effect in the adsorption of Cu(II), Pb(II), Ni(II) from aqueous solutions

In this work, the capability of hybrid of functionalized Carbon nanotube and fullerene (C60) as novel adsorbent was studied in order to remove copper, nickel and lead ions. This hybrid was tested for adsorption of heavy metals such as copper, nickel and lead, at pH 2 and 8 conditions for first time. At pH of 8 and for 30 min of the contact time, the concentration of lead, copper and nickel ions reached from 20 to 0.25, 5.4 and 18.07 ppm, respectively. For 30 min and pH 2, the percentage of removal of metal ions were about 13%. The results showed that the removal efficiency was low at pH 2 and high at pH 8. Also, after the metal ions adsorption, the recovery and regeneration process were done by placing adsorbent in strong acids for removing metals from their surface. The highest values of correlation coefficient (R-2) were obtained in the Pseudo-second-order model for adsorption of Pb (1), Cu (0.994) and Ni (0.981). The best adsorption isotherm models and correlation coefficients for each ion were Langmuir with 0.987 for Pb, Freundlich with 0.985 for Cu, and Freundlich with 0.999 for Ni.