Biosorption of heavy metals to immobilised Phormidium laminosum biomass

The capacity to biosorb Cu(II), Fe(II), Ni(II) and Zn(II) by non-viable bio mass of the cyanobacterium Phormidium laminosum entrapped in polysulfone an d epoxy resin beads was investigated. The biosorption process depended on t he wetting of biomass beads, the rate of metal biosorption decreasing when dry biomass beads were used. A decrease in the immobilised biomass bead siz e led to an increase in the rate of metal biosorption. The amount of metal biosorbed increased with the biomass and the amount of metal available. The biosorbed metal was completely desorbed from the biomass beads by washing with 0.1 M HCl. Polysulfone biomass beads can be reused for, at least, ten consecutive biosorption/desorption cycles without apparent loss of efficien cy after its reconditioning with 0.1 M NaOH. (C) 1999 Elsevier Science B.V. All rights reserved.