Examination of the Effects of Activated Carbon Produced from Coal Using Single-Step H3PO4/N2+H2O Vapor Activation on the Adsorption of Bovine Serum Albumin at Different Temperatures and pH Values

This study examined protein adsorption equilibrium and kinetics on activated carbon (AC) that we obtained from coal by single-step H 3 PO 4 activation under N 2 +H 2 O vapor at 800 °C. Surface properties, pore size distribution, and volumes of AC were determined using volumetric method with N 2 adsorption at 77 K. Also, the textural properties were characterized by SEM-EDAX and XRD. The zeta potential values were measured to elucidate the electrostatic interactions between the protein and AC. The obtained AC discrete system was also used as an adsorbent for adsorbing bovine serum albumin (BSA) from aqueous solution. The effects of pH (4.0, 5.0, and 7.4) and temperatures (20, 30 and 40 °C) on the adsorption of BSA on AC were examined. The surface area, micropore, mesopore and total pore volumes of AC were found to be 1175 m 2 /g , 0.477 cm 3 /g, 0.061 cm 3 /g and 0.538 cm 3 /g, respectively. The optimum temperature for AC in BSA adsorption was found to be 40 °C and the pH was found to be 4.0. The highest BSA adsorption was found to be 159 mg/g and pH to be 4.0. The experimental equilibrium data were compared with the Langmuir and Freundlich models and found to be compatible with both models. The adsorption process is best described by the pseudo-first-order kinetic model. As a result, it was found out that AC obtained by single step H 3 PO 4 /N 2 +H 2 O vapor activation is an effective adsorbent for the adsorption of BSA from aqueous solution.