Adsorption and Desorption of Cu / Zn Ions with Triethylenetetramine-Functionalized Adsorbents: Kinetics Study

Adsorption and desorption kinetics is critical in the efficiency and performance evaluation of the adsorbents. In this study, the adsorption and desorption kinetics of copper and/or zinc ions was investigated with the polyamine-functionalized adsorbents (P-TETA). The adsorption kinetics was studied in both single species system (when only one metal ion was present) and binary species system (when both metal ions were present). The adsorption kinetics in single species system was well fitted with two models at two stages for both Cu and Zn ions, indicating that the adsorption was diffusion-controlled at the initial stage and attachment-controlled at later stage. The adsorption kinetics in binary species system revealed the stronger coordination affinity of Cu ion with P-TETA than Zn ion. The desorption kinetics was well fitted with Elovich model for Cu ion desorption only, in both single and binary species system, with a higher desorption rate in single species system.