Removal and recovery of radionuclides and toxic metals from wastes, soils and materials
A process has been developed at Brookhaven National Laboratory (BNL) for the removal of metals and radionuclides from contaminated materials, soils, and waste sites (Figure 1). In this process, citric acid, a naturally occurring organic complexing agent, is used to extract metals such as Ba, Cd, Cr, Ni, Zn, and radionuclides Co, Sr, Th, and U from solid wastes by formation of water soluble, metal-citrate complexes. Citric acid forms different types of complexes with the transition metals and actinides, and may involve formation of a bidentate, tridentate, binuclear, or polynuclear complex species. The extract containing radionuclide/metal complex is then subjected to microbiological degradation followed by photochemical degradation under aerobic conditions. Several metal citrate complexes are biodegraded and the metals are recovered in a concentrated form with the bacterial biomass. Uranium forms binuclear complex with citric acid and is not biodegraded. The supernatant containing uranium citrate complex is separated and upon exposure to light, undergoes rapid degradation resulting in the formation of an insoluble, stable polymeric form of uranium. Uranium is recovered as a precipitate (uranium trioxide) in a concentrated form for recycling or for appropriate disposal. This treatment process, unlike others which use caustic reagents, does not create additional hazardous wastes for disposal and causes little damage to soil which can then be returned to normal use.
- Research Organization:
- Brookhaven National Lab., Upton, NY (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 10191371
- Report Number(s):
- BNL-49508; CONF-9310179-2; ON: DE94001893; TRN: 94:000064
- Resource Relation:
- Conference: CONEC `93: conference on environmental commerce,Chattanooga, TN (United States),17-20 Oct 1993; Other Information: PBD: Jul 1993
- Country of Publication:
- United States
- Language:
- English
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BIOREMEDIATION OF URANIUM CONTAMINATED SOILS AND WASTES.
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12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
SOILS
REMEDIAL ACTION
RADIONUCLIDE MIGRATION
METALS
CONTAMINATION
RADIOACTIVE WASTE FACILITIES
CITRIC ACID
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PHOTOSENSITIVITY
URANIUM
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WASTE MANAGEMENT