Adsorption of Pb^2 +, Ni^2 +, Cu^2 +, Co^2 + 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 Pb^2 +, Ni^2 +, Cu^2 +, and Co^2 + 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 Pb^2 +, Ni^2 +, Cu^2 +, and Co^2 + metal ions uptake by the PPI/SiO₂ were evaluated. The results revealed that the highest adsorption capacity of Pb^2 +, Ni^2 +, Cu^2 +, and Co^2 + 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 ΔS, ΔH and ΔG indicated that the uptake of Pb^2 +, Ni^2 +, Cu^2 +, and Co^2 + 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.