Hydrogels for immobilization of bacteria used in the treatment of metal-contaminated wastes

Polymeric matrices prepared by gamma irradiation of 2-hydroxyethyl methacrylate and 2-hydroxyethyl acrylate at -78degreesC in the presence of water and glycerol and poly(vinyl alcohol) membranes were examined as carriers for immobilization of bacterial cells in experiments of metal decontamination. Bacterial strains capable of growing in the presence of heavy metals were selected from soil and water from the Rio de la Plata coasts in Argentina and cultured in the hydrophilic membranes with the aim of bioremediation of the standard contaminated solutions. The results obtained indicate that removal from free bacteria was more efficient for Pb(II) and Cd(II) than for Cr(III) and Cu(II). It was ascertained that all metals could be immobilized in the polymer matrices to some extent. The Cr(III) ion concentration in bacteria immobilized on the acrylic hydrogel was approximately double of that found in the poly(vinyl alcohol) membrane. (C) 2001 Elsevier Science Ltd. All rights reserved.