The interactions between algal biomass and various metal ions were investigated. For most of the ions examined, uptake is dependent upon pH, with cations bound most strongly above pH 4 and complex anions bound most strongly at lower pH values. However, the binding of gold(III), silver, and mercury(II) ions is relatively insensitive to Ph. Heat-treatment of the biomass was found to have little effect on binding capacity. As with other ion-exchange matrices, the extent of metal-ion removal is strongly influenced by the solution composition — in particular, the presence of competing ligands. However, unlike conventional strong-acid cation-exchange resins, the algal biomass displays low affinity for Ca+2 and Mg+2 and, thus, may be especially well-suited for hard-water treatment applications. Algal biomass can be readily immobilized in silica to produce a durable chromatographic support which shows substantial longevity in lab-scale operations.