Batch reactor vs. flow column - Mechanistic investigation and modeling of Au(III) ions adsorption from aqueous solutions containing Ni2+, Na+, Cl− and ClO4− as impurities

In this paper, a mechanistic analysis of the adsorption and reduction of gold(III) chloride complex ions on the activated carbon surface were described. All experiments were performed in the presence of nickel ions. Obtained results confirm that there is no influence of light and heavy cations on the adsorption process. From the Arrhenius equation, activation parameters such as activation energy (17.53 ± 0.98 kJ/mol) and pre-exponential (28.7 ± 8.91 min−1) factor were determined. SEM and XRD, as well as XPS analysis, have confirmed the presence of metallic gold on the surface of activated carbon. The concentration distribution of gold inside activated carbon after adsorption process both for continuous stirred tank reactor and continuous flow reactor was determined. New estimator for interfacial area of mass transfer was defined.