Kinetics and Equilibrium Models for Sorption of Cu(II) onto a Novel Manganese Nano-adsorbent

Abstract

The studies of kinetics and equilibrium sorption of Cu(II) were undertaken using nanoscale zerovalent manganese (nZVMn) synthesized by chemical reduction in a single pot system. nZVMn was characterized using scanning electron microscopy, energy dispersive x-ray, and surface area determined by Brunauer–Emmett–Teller. The effect of pH, contact time, adsorbent dose, agitation speed, initial Cu(II) concentrations, temperature, and ionic strength on the sorption of Cu(II) onto nZVMn were investigated in a batch system. The kinetic data followed pseudo-second-order. The mechanism was governed by pore diffusion. The equilibrium sorption data were tested by Freundlich, Langmuir, Temkin, Dubinin–Kaganer–Raduskevich, and Halsey isotherm models. The Langmuir monolayer adsorption capacity (Q_max = 181.818 mg/g) is much greater compared to other nano-adsorbents used in sorption of Cu(II). The thermodynamic parameters (ΔH⁰, ΔS⁰, ΔG⁰) revealed a feasible, spontaneous, and endothermic adsorption process. nZVMn has a great potential for effective removal of copper (II) in aqueous solution.

GRAPHICAL ABSTRACT

Keywords:

• Adsorption
• copper
• kinetics
• manganese nanoparticles
• salinity
• spontaneous

ACKNOWLEDGMENTS

Oluwasogo Adewumi Dada appreciates the opportunity granted to him by Landmark University to undertake Ph.D. program at University of llorin. The assistance for SEM/EDX analyses rendered by Dr Ogunlaja Adeniyi of Rhodes University, South Africa, is thankfully acknowledged