Modification of commercial activated carbon and investigation of its BSA adsorption properties

Protein adsorption has been widely studied by many researchers. Fabrication of novel materials for protein adsorption, elucidating adsorption mechanisms and integrating adsorpstion process to the industrial production have been important goals for these studies. In this study, the commercially available powder activated carbon (CAC) sample to further improve its surface properties was modified first by treatment with sodium carbonate, secondly thermally treated by microwave technique, and finally subjected to treatment with HCl. The treated activated carbon samples under various modifiying conditions were named as MCAC1, MCAC2, MCAC3, MCAC4 and MCAC5. MCAC4 sample was found to be the most appropriate sample among other samples obtained at various modification conditions, according to BET analysis results obtained for each sample. The results indicated that it was possible to increase surface area of the CAC after modification process (named as MCAC4) up to 2492 square meter per gram with the enhancement percentage of 59%, compared to initial untreated CAC sample. Then, CAC and MCAC4 samples were used in the series of Bovine Serum Albumin (BSA) adsorption experiments. The data obtained from the experiments were fitted to isotherm models and then they were used to explain adsorption mechanisms. The adsorption experiments were carried out at pH values ranging from 4 to 8 and temperature values ranging from 25 to 40 °C. The maximum adsorpstion value according to the Langmuir Isotherm Model was found as 134.77 mg/g at pH 5 and 40 °C for CAC sample, and 139.37 mg/g at pH 4 and 40 °C for MCAC4 sample. The kinetics of adsorption studies were also carried at pH values ranging from 4 to 8 and temperature values ranging from 25 to 40 °C. According to the results obtained, Pseudo 2. Order model was found to be the best fit among other models applied.