Adsorption of Pb2+, Ni2+, Cu2+, Co2+ metal ions from aqueous solution by PPI/SiO2 as new high performance adsorbent: Preparation, characterization, isotherm, kinetic, thermodynamic studies

Amino functional poly propyleneimine (PPI, G5) dendrimer linked silica (PPI/SiO2) was synthesized with a divergent procedure. PPI/SiO2 nanohybrid was analyzed by XRD, FTIR, TGA, BET, Zeta potential, TEM and SEM. The above analysis was applied to determine good grafting between PPI and SiO2. The adsorption performance of the PPI/SiO2 nanohybrid for the uptake of Pb2+, Ni2+, Cu2+, and Co2+ metal ions was monitored under the efficacy of nanohybrid dosage, metal ion concentration, contact time, solution pH, and regeneration. The outputs of the investigation showed high removal efficiency and great desorption performance. The isotherms, kinetics and thermodynamics of Pb2+, Ni2+, Cu2+, and Co2+ metal ions uptake by the PPI/SiO2 were evaluated. The results revealed that the highest adsorption capacity of Pb2+, Ni2+, Cu2+, and Co2+ onto PPI/SiO2 was 700, 800, 900 and 1000 mg/g at 298 K pursuant to an analysis using the Langmuir model that was coordinated very good to the sorption data. The outputs of the kinetic investigations' demonstrated that the adsorption procedure fitted the pseudo second-order equation. The monitored thermodynamic parameters of Delta S, Delta H and Delta G indicated that the uptake of Pb2+, Ni2+, Cu2+, and Co2+ metal ions by PPI/SiO2 was spontaneous and endothermic. This research illustrated that PPI/SiO2 could be successfully applied as a high performance adsorbent for heavy metal ions removal from aqueous solutions. (C) 2017 Elsevier B.V. All rights reserved.