Recovery of Platinum from Dilute Chloride Media Using Biosorbents

Pistachio nut shells and Rice husk, a biomass residue, were investigated as adsorbents for the platinum uptake from synthetically prepared dilute chloroplatinic acid solutions. The effects of the different uptake parameters on platinum uptake (%) were studied in detail on a batch sorption. Before the pistachio nut shell material was activated, platinum uptake (%) was poor compared with rice husk. However, after the pistachio nut shell material was activated at 1000°C under an argon atmosphere, the platinum uptake (%) increased two-fold. The pistachio nut shell (inactivated and activated) and rice husk were characterized by Attenuated Total Reflection-Fourier transform infrared spectroscopy (ATR-FTIR). The uptake equilibrium data were best fitted with the Langmuir isotherm model. The maximum uptake capacities, Q_max, at 25°C were found to be 38.31 and 42.02 mg/g for the activated pistachio nut shell and rice husk, respectively.