Kinetic studies of the removal of Pt(IV) chloride complex ions from acidic aqueous solutions using activated carbon

In this paper, results showing the possibility of activated carbon application in platinum recovery from aqueous solution are presented. The studies were performed with the commercially available activated carbon, and the results can be easily transferred directly to the industry. The influence of pH, mixing rate, and amount of activated carbon as well as platinum(IV) initial concentration on the rate of adsorption was investigated. It was shown that after adsorption platinum is present on the surface of activated carbon in two oxidation states, +2 and +4, where shares of those forms are equal to 47 and 53%. Moreover, the enthalpy and entropy of activation were determined and are equal to 16.14 +/- 075 kJ mol(-1) and 42.19 +/- 0.28 J mol(-1) K-1.