Cadmium and lead ions can be removed simultaneously from a binary aqueous solution by the sono-sorption method

This paper presents the effect of ultrasound on the simultaneous removal of Cd2+ and Pb2+ ions from a binary aqueous solution in the presence of natural sorbent (sono-sorption method). The obtained results compare with the results of control method which was achieved in the absence of ultrasound. The experiments under sonication were carried out by 20 kHz apparatus. The effect of different parameters such as the amount of sorbent, contact time, temperature, and specially the competitive sorption of ions were considered for both methods. It is found that the sorption efficiency of Cd2+ was decreased in the presence of Pb2+. But, the presence of Cd2+ had a negligible effect on the removal of Pb2+. The results show that in the binary solution, the removal efficiency was higher in the presence of ultrasound than the control method. Both ions in binary solution can be removed to near completion with ultrasound. Two different multi-component isotherm equations based on the Langmuir isotherm were applied on the studied system to predict the sorption behavior of the components.