Nano composite a potential low cost adsorbent for removal of cyanine acid

In this study, CuFe2O4/sawdust nano magnetic composite was prepared by chemical co-precipitation method. The nano composite was characterized by Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). SEM image showed the spherical shape with particle size 50 nm for CuFe2O4/sawdust composite. The CuFe2O4/sawdust composite was used for removal of cyanine acid blue (CAB) from aqueous solution. The maximum percentage of CAB adsorption was found at pH 2 and 15 min contact time with CuFe2O4/sawdust composite. Kinetic and isotherm studies were carried out. The sorption was analyzed using pseudo-first order and pseudo-second order kinetic model. The sorption kinetics was found to follow a pseudo-second order kinetic model. The equilibrium data in aqueous solutions were fitted to Langmuir and Freundlich isotherm and the equilibrium adsorption of CAB was best described by Langmuir isotherm model. The thermodynamic parameters like standard Gibb's free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) were evaluated. The adsorption of CAB onto CuFe2O4/sawdust composite is exothermic and negative value of ΔG° confirms the spontaneous process. The solid composite could be conveniently regenerate after adsorption.

► The nano composite (CuFe2O4/sawdust) adsorbent shows good adsorption capacity for acid cyanine blue dye (CAB).
► The adsorption process follows the pseudo-second-order kinetic model.
► The adsorption process of CAB onto composite from thermodynamic view (standard Gibb's free energy (ΔG°)) is suitable.
► Use of friendly environment and inexpensive sorbent (CuFe2O4/sawdust).