Determined of Equilibrium Adsorption Isotherm Model Pertechnetate Oxoanion Onto Activated Carbon

Four well-known isotherm models were appropriated to investigate the adsorption process mechanism in the radioactive 99mTcO4- adsorption from aqueous solution by using activated carbon as adsorbent. According to R2 values, the experimental data is found to be suitable for the four isotherm models. However, when the adsorption capacities of the experimental and calculated from models are compared, it has been seen that the isotherm models best suited to the experimental data are Langmuir and Temkin. The maximal monolayer adsorption capacity value founded from Langmuir isotherm model is 3170 μCi.g-1. The dimensionless separation factor (RL) value indicating a favorable adsorption experiment is 0.126. Also from Freundlich Isotherm model, the adsorption intensity (n) value which indicates favorable adsorption is 1.72. The heat of adsorption process was estimated from Temkin Isotherm model to be 724 J/mol and the mean free energy was estimated from D-R isotherm model to be 13.4 J/mol. According to these data, it can be said that the adsorption process is realized by physical adsorption. The results showed that the activated carbon was to be a successful adsorbent for the removal of radioactive 99mTcO4- from aqueous solutions