Abstract
In this research, the adsorption of bovine serum albumin (BSA) onto activated carbon (AC) obtained from apple bark was carried out and the thermodynamic parameters of adsorption process were investigated. Besides, the functions involved in BSA attachment were examined by adsorption experiments on retention capacities for BSA at 298 K, pH of 7, ionic strength of 5.10(-2) M, and initial concentration of 5.10(-2) g L-1, respectively. The bovine serum albumin (BSA) adsorption experiment onto activated carbon (AC) indicated that the highest adsorption yield was achieved at pH 5.5. The BSA molecules at pH 5.5 are very stable and that pH value is close to isoelectronic point of BSA. The surface structural change of BSA and activated carbon was studied before and after the experiment using scanning electron microscopy (SEM) analysis and Fourier Transform Infrared Spectroscopy (FTIR). By the way, the thermodynamic functions such as Gibbs free energy (Delta G*), activation energy (Ea), activation entalphy (Delta H*), and activation entropy (Delta S*) were calculated as - 66.17, 37.73, - 29.09 kJ mol(-1), and + 124.42 J mol(-1) K-1 for bovine serum albumin (BSA) adsorption, respectively. The adsorption of the process was investigated using Eyring and Arrhenius equations and the adsorption kinetic of BSA on AC was found to be coherent with the pseudo-second-order model.