Evaluation of the Cd, Cu, and Zn Biosorption in Two‐Metal Systems Using an Algal Biosorbent

Abstract
The equilibrium sorption capacity of the formaldehyde‐cross‐linked brown seaweed Ascophyllum nodosum biomass was studied using two‐metal systems comprising either (Cu + Zn), (Cu + Cd), or (Zn + Cd). Three‐dimensional sorption isotherm surfaces were used in the evaluation of sorption performance, replacing simple isotherm curves. While each of the metals tested can inhibit the sorption of the others, at low total residual metal concentrations the total metal sorption uptake increases. At higher total metal concentrations, the total metal sorption uptake either remains constant, or there may be a slight decrease compared to single‐metal uptakes. This is an indication of a mutual interference in the sorption uptake of the two metals tested in each system.