Bacteria immobilisation on hydroxyapatite surface for heavy metals removal

These systems were tested using solutions of Zn(II), Cd(II) and in solutions containing both metals. A synergistic effect between the strains and HAp, which is effective in removing the target heavy metals on its own, was observed, as the combination of HAp with the bacterial strains led to higher adsorption capacity for both elements.

Selected bacterial strains were immobilised on the surface of hydroxyapatite (Ca-10(PO4)(6)(OH)(2) - HAp) of natural origin (fish bones). The capacity of the material, alone and in combination with the bacterial strains to act as heavy metal removers from aqueous streams was assessed. Pseudomonas fluorescens (S3X), Micro bacterium oxydans (EC29) and Cupriavidus sp. (1C2) were chosen based on their resistance to heavy metals and capacity of adsorbing the metals.