Biosorption potentials of a novel green biosorbent Saccharum bengalense containing cellulose as carbohydrate polymer for removal of Ni (II) ions from aqueous solutions

In this research work, the potential of a novel green material obtained from Saccharum bengalense (SB) plant was investigated for the removal of Ni (II) ions from aqueous solution. Biomaterial SB composed of cellulose macromolecules and was used without any chemical treatment. Batch experiments were performed by considering the effect of contact time, SB concentration, pH of the solution and temperature. Results revealed that ∼87% of Ni was removed from aqueous solution at optimum conditions. Three typical kinetic models namely, pseudo first order, pseudo second order and Elovich equations were applied to interpret the kinetic data. To investigate the rate determining step, the intra-particle diffusion model was applied on the experimental data. The sorption process was well explained with pseudo second-order kinetic model. Adsorption isothermal data was examined by applying classical two parameters (Langmuir, Freundlich, Timken and Dubinin-Radushkevich) and three parameters (Redlich-Peterson, Toth and Sips models) and four parameters Fritz Schlunder Isotherm models. Based on R2 and χ2 the equilibrium sorption data was better fitted to Langmuir and Sips isotherm model than any other model. Thermodynamics parameters such as free energy change (ΔG°), enthalpy change (ΔH°) and entropy change (ΔS°) have been calculated respectively, which revealed the spontaneous, endothermic and feasible nature of adsorption process. The results of the present investigation suggest that S. bengalense can be used as an environmentally benign and low cost biomaterial for nickel removal from aqueous solution.