Biosorption of toxic, heavy, no-carrier-added radionuclides by calcium alginate beads

Studies on adsorption behavior of heavy radionuclides, present altogether in no-carrier-added state, e. g., Pb197-200, 197-200TI and Hg-197, have been carried out with calcium alginate beads. High lead (100%) and moderate thallium removal (similar to 65%) was achieved in pH range 2-7. 100% mercury removal was also achieved at pH 2 and 4. Effort has been made to recover all three radionuclides adsorbed in the calcium alginate beads using various chemicals, such as HCl, thiourea, sodium acetate, sodium oxalate and sodium nitrite. It was found that 0.1M HCl and 0.1M thiourea could remove at pH 1 80 - 90% of adsorbed Pb. Tl recovery was possible by all chemicals mentioned above. Hg was also recovered by all chemicals except HCl.