Biosorption of Cd(II) from aqueous solution using xanthated nano banana cellulose: equilibrium and kinetic studies.

Present study explored the biosorption capacity of xanthated nano banana cellulose (XNBC) for Cd(II) from aqueous solution. The biosorbent containing sulfur-bearing groups have a high affinity for heavy metals. Sulfur can be considered as a soft ligand group having strong affinity for cadmium. In the present study, the influence of various important parameters such as pH, time, biosorbent dose and initial Cd(II) concentration on the biosorption capacity were investigated. The maximum biosorption capacity of XNBC for Cd(II) was found to be 154.26 mg g⁻¹ at 298 K. The Cd(II) sorption of XNBC was confirmed by SEM-EDS and XRF analysis. The isotherms such as Langmuir, Freundlich, Redlich-Peterson and Tempkin were studied. The Langmuir and the Redlich-Peterson isotherms had been well fitted the biosorption of Cd(II) with xanthated nano banana cellulose. The kinetics of Cd(II) removal using XNBC was well explained by second-order kinetic model. The thermodynamic parameters were also evaluated from the biosorption measurements. Among the various desorbing agents tested, the desorbing efficiency was found to be maximum with 0.1 mol L⁻¹ HCl. It was found that XNBC is also suitable to be used under column operation.