Evaluation of activated carbon and bio-polymer modified activated carbon performance for palladium and platinum removal

Because of the increase in needs for platinum group metals, as well as their low availability in nature and their environmental concerns, it is getting more urgent to separation and recovers them from dilute solutions. In this research, commercial activated carbon was used to optimize the palladium and platinum removal by applying the Taguchi approach. According to the results, the optimum operating conditions for palladium and platinum removal by activated carbon were pH = 2, particle size of adsorbent = 0.21 mm and adsorbent dose = 10 g/L. Under these optimum operating conditions, more than 98% of palladium and platinum were removed by activated carbon in 3 h. The equilibrium adsorption data were well described by the Langmuir and Freundlich models. While commercial activated carbon had the palladium and platinum adsorption capacity of 35.7 and 45.5 mg/g, respectively, the bio-polymer modified activated carbon was able to adsorb 43.5 and 52.6 mg/g of palladium and platinum, respectively. It was observed that the adsorption kinetics of palladium and platinum on these adsorbents could be well analyzed with pseudo-second-order model. (C) 2012 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.