RELEASE OF U(VI) FROM SPENT BIOSORBENT IMMOBILIZED IN CEMENT CONCRETEBLOCKS

This paper deals with cementation as the method for the disposal of sp ent biosorbent, Ganoderma lucidum (a wood rotting macrofungi) after it is used for the removal of Uranium. Results on the uranium release du ring the curing of cement - concrete (CC) blocks indicated that placin g the spent sorbent at the centre of the blocks during their II. casti ng yields better immobilization of uranium as compared to the homogene ous mixing of the spent sorbent with the cement. Short term leach test s indicated that the uranium release was negligible in simulated seawa ter, 1.8% in 0.2 N sodium carbonate and 6.0% in 0.2 N HCl. The latter two leachates were used to represent the extreme environmental conditi ons. It was observed that the presence of the spent biosorbent up to 5 % by weight did not affect the compressive strength of CC blocks. Thus cementation technique is suitable for the immobilization of uranium l oaded biosorbent for its ultimate disposal.