Polypropylene imine dendrimer/carbon nanotube as an impressive adsorbent for cadmium, copper and lead elimination from wastewater: Isotherms, kinetics and thermodynamic

Abstract Herein, highly ordered and branched polymeric polypropylene imine dendrimer-carbon nanotube-composite ( denoted as PPI/MWCNT) was synthesized and characterized using XPS, FTIR, RAMAN, SEM, TEM, TGA, and Zeta potential analyses. The synthesized nanocomposite was used to eliminate Cd 2+ , Cu 2+ , and Pb 2+ from industrial effluent. The efficacies of pH, adsorbate concentration, time, and dosage in the removal process were assayed. Optimum conditions for the elimination efficiencies of Cd 2+ , Cu 2+ , and Pb 2+ were dosage: 0.06 g/L; adsorbate concentration: 100 mg/L; and adsorption time: 20 min, and pH: 7). The utmost adsorption capacities of Cd 2+ , Cu 2+ , and Pb 2+ were 1620, 1590, and 1460 mg/g, respectively, which are fitted with the isotherm and kinetic equilibrium data to the Langmuir model and the pseudo-second-order, respectively. Desorption of the Cd 2+ , Cu 2+ , and Pb 2+ ions from the surface of PPI/MWCNT was best carried out with removal efficiency of 84%, 87%, and 92%. Therefore, PPI/MWCNT possesses a considerable capacity for eliminating metal ions from industrial wastewater and reusability after the desorption step.