Dactyloctenium aegyptium biomass (DAB)-MMT nano-composite: Synthesis and its application for the bio-sorption of Cu(II) ions from aqueous solution

Dactyloctenium aegyptium biomass (DAB), a novel plant based material was modified with Montmorillonite (MMT) clay to form DAB-MMT nano-composite as an adsorbent for the removal of Cu(II) ions from the aqueous solution. The surface morphology of the adsorbent was characterized by using scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX) and FTIR Fourier transform-infrared spectroscopy (FT-IR) analysis. The adsorption equilibrium was reached in 60 min and the optimum pH for adsorption was found to be 6. Equilibrium isotherm data were analysed using Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (D-R) isotherm models at 30, 40 and 50 °C and were best followed at 30 and 40 °C. Maximum adsorption capacity (qm) as calculated from Langmuir isotherm was found to be 18.51 mg g−1. Adsorption kinetics of Cu(II) onto DAM-MMT nano-composite was also studied using pseudo-first order, pseudo-second order and intra particle diffusion model over a wide range of concentration (10-100 mg L−1) and the adsorption of Cu(II) followed pseudo-second order kinetics showing that chemisorption process was involved. The thermodynamics parameters showed that the process was endothermic and spontaneous. The breakthrough and exhaustive capacities were found to be 10 mg g−1 and 25 mg g−1 respectively.