Removal of Radioactive Cations and Anions from Polluted Water using Ligand-Modified Colloid-Enhanced Ultrafiltration
- Univ. of Oklahoma, Norman, OK (United States)
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
The purpose of this project was to develop, optimize, and evaluate new separation methods for removal of hazardous (radionuclides and toxic non-radioactive contaminants) metal ions from either ground water or aqueous waste solutions produced during Decontamination and Decommissioning operations at DOE sites. Separation and concentration of the target ions will result in a substantial reduction in the volume of material requiring disposal or long-term storage. The target metal ions studied were uranium, thorium, lead, cadmium, and mercury along with chromium (as chromate). The methods tested use membrane ultrafiltration in conjunction with water-soluble polymers or surfactants with added metal-selective chelating agents. Laboratory scale tests showed removal of 99.0-99.9% of each metal tested in a single separation stage. The methods developed for selective removal of radionuclides (UO22+, Th4+) and toxic heavy metals (Pb2+, Cd2+, Hg2+) are applicable to two DOE focus areas; decontamination of sites and equipment, and in remediation of contaminated groundwater. Colloid-enhanced ultrafiltration methods have potential to be substantially less expensive than alternative methods and can result in less waste. Results of studies with varying solution composition (concentration, acidity) and filtration parameters (pressure, flow rate) have increased our understanding of the fundamental processes that control the metal ion separation and colloid recovery steps of the overall process. Further laboratory studies are needed to improve the ligand/colloid recovery step and field demonstration of the technology is needed to prove the applicability of the integrated process. A number of graduate students, post-doctoral associates, and research associates have received training and research experience in the areas of separation science, colloid chemistry, and metal ion coordination chemistry of radionuclides and toxic metals. These scientists, some with positions in industry and academia, have the necessary background to address problems related to environmental remediation and. management. The results of this research show the technical feasibility of this separation technique to concentrate radionuclides and toxic metals. The technology developed during this project has wider applications and has been studied for removal of chromate or chlorinated phenolics from industrial wastewater. In several cases, field tests have shown that using colloid-based ultrafiltration is feasible on real-world polluted waters.
- Research Organization:
- Univ. of Oklahoma, Norman, OK (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- FG07-97ER14825
- OSTI ID:
- 789796
- Report Number(s):
- DOE/ER/-14825; 60041-OK
- Country of Publication:
- United States
- Language:
- English
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Removal of Radioactive Cations Anions from Polluted Water Using Ligand-Modified Colloid-Enhanced Ultrafiltration (60041-OK)
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