The use of immobilised biomass to remove and recover radium from Elliot Lake uranium tailing streams

Return sludge from a municipal wastewater treatment plant was killed and subsequently immobilised in the form of particles of approximately 1 mm in diameter. The immobilised biomass particles were then tested for their capacity to adsorb selectively radium-226 from the waste waters of the uranium mining and milling operations in Elliot Lake, Ontario. Both the adsorption equilibrium and the kinetics of radium uptake were examined. The elution of the adsorbed radium from the biomass particles and the subsequent reuse of the particles for additional radium uptake were also looked at. This information has provided an improved understanding of the way the immobilised biomass functions as a radium adsorbent.