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Title: Removal of Radioactive Cations and Anions from Polluted Water using Ligand-Modified Colloid-Enhanced Ultrafiltration

Abstract

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 (UO 2 2+, Th 4+) and toxic heavy metals (Pb 2+, Cd 2+, Hg 2+) 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 thatmore » 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.« less

Authors:
 [1];  [1];  [2]
+ Show Author Affiliations
  1. Univ. of Oklahoma, Norman, OK (United States)
  2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
Research Org.:
Univ. of Oklahoma, Norman, OK (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
789796
Report Number(s):
DOE/ER/-14825
60041-OK
DOE Contract Number:
FG07-97ER14825
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
polluted water; radioactive cations and anions; ligand-modified; ultrafiltration; colloid-enhanced; radionuclides

Citation Formats

Scamehorn, John F, Taylor, Richard W, and Palmer, Cynthia E. Removal of Radioactive Cations and Anions from Polluted Water using Ligand-Modified Colloid-Enhanced Ultrafiltration. United States: N. p., 2001. Web. doi:10.2172/789796.
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Scamehorn, John F, Taylor, Richard W, & Palmer, Cynthia E. Removal of Radioactive Cations and Anions from Polluted Water using Ligand-Modified Colloid-Enhanced Ultrafiltration. United States. doi:10.2172/789796.
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Scamehorn, John F, Taylor, Richard W, and Palmer, Cynthia E. Mon . "Removal of Radioactive Cations and Anions from Polluted Water using Ligand-Modified Colloid-Enhanced Ultrafiltration". United States. doi:10.2172/789796. https://www.osti.gov/servlets/purl/789796.
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@article{osti_789796,
title = {Removal of Radioactive Cations and Anions from Polluted Water using Ligand-Modified Colloid-Enhanced Ultrafiltration},
author = {Scamehorn, John F and Taylor, Richard W and Palmer, Cynthia E},
abstractNote = {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.},
doi = {10.2172/789796},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Dec 17 00:00:00 EST 2001},
month = {Mon Dec 17 00:00:00 EST 2001}
}
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Technical Report:
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DOI:  10.2172/789796
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  • ; ;
    'The objectives of this project are to determine the feasibility of and develop optimum conditions for the use of colloid-enhanced ultrafiltration (CEUF) methods to remove and recover radionuclides and associated toxic non-radioactive contaminants from polluted water. The target metal ions are uranium, plutonium, thorium, strontium and lead along with chromium (as chromate). Anionic chelating agents, used in conjunction with polyelectrolyte colloids, provide a means to confer selectivity required for removal of the target cations. This project entails a comprehensive study of the effects of solution composition and filtration unit operating parameters on the separation efficiency and selectivity of ligand modifiedmore » colloid-enhanced ultrafiltration (LM-CEUF) processes. Problem areas identified by the Office of Environmental Management addressed by this project include removal of hazardous ionic materials from groundwater, aqueous waste solutions and mixed waste. Separation and concentration of the target ions will result in a substantial reduction in the volume of material requiring long-term storage. This report summarizes work after 8 months of a 3-year project.'« less

  • ; ;
    The objectives of this project are to determine the feasibility of and develop optimum conditions for the use of colloid-enhanced ultrafiltration (CEUF) methods to remove and recover radionuclides and associated toxic nonradioactive contaminants from polluted water. The target metal ions are uranium, plutonium, thorium, strontium and lead along with chromium (as chromate). Anionic or amphiphilic chelating agents, used in conjunction with polyelectrolyte colloids, provide a means to confer selectivity required for removal of the target cations. This project entails a comprehensive study of the effects of solution composition and filtration unit operating parameters on the separation efficiency and selectivity ofmore » ligand modified colloid-enhanced ultrafiltration (LM-CEUF) processes. Problem areas identified by the Office of Environmental Management addressed by this project include removal of hazardous ionic materials from ground water, mixed waste, and aqueous waste solutions produced during decontamination and decommissioning operations. Separation and concentration of the target ions will result in a substantial reduction in the volume of material requiring disposal or long-term storage.« less

  • ; ;
    The objectives of this project are to determine the feasibility of and develop optimum conditions for the use of colloid-enhanced ultrafiltration (CEUF) methods to remove and recover radionuclides and associated toxic non-radioactive contaminants from polluted water. The target metal ions are uranium, plutonium, thorium, strontium, cadmium, and lead along with chromium (as chromate). Anionic or amphiphilic chelating agents, used in conjunction with polyelectrolyte colloids, provide a means to confer selectivity required for removal of the target cations. This project entails a comprehensive study of the effects of solution composition and filtration unit operating parameters on the separation efficiency and selectivitymore » of ligand modified colloid-enhanced ultrafiltration (LM-CEUF) processes. Problem areas identified by the Office of Environmental Management addressed by this project include removal of hazardous ionic materials from ground water, mixed waste, and aqueous waste solutions produced during decontamination and decommissioning operations. Separation and concentration of the target ions will result in a substantial reduction in the volume of material requiring disposal or long-term storage.« less

  • ; ; ; ... - Langmuir; (United States)
    A mixture of a cationic polyelectrolyte, poly(diallyldimethylammonium chloride) or PDADMAC, and the anionic ligand diethylenetriaminepentaacetic acid (DTPA) can be added to aqueous streams as a water-soluble colloid to bind simultaneously divalent cations, such as Cu[sup 2+] and Pb[sup 2+], and anions, such as CrO[sub 4][sup 2[minus]]. At pH values greater than about 4, most of DTPA is attached electrostatically to the PDADMAC, so that the ligand remains in the retentate in ultrafiltration (UF) separations. Equilibrium dialysis studies show the effectiveness of the PDADMAC-DTPA mixture in binding ions of various types; the data also show that cations such as Ca[sup 2+],more » which do not bind to the ligand, are expelled and become concentrated in the permeate solution passing through the membrane. In equilibrium dialysis and UF experiments, with the PDADMAC-DTPA mixture added to a feed stream containing a mixture of Cu[sup 2+] and CrO[sub 4][sup 2[minus]], the bound cations and anions become highly concentrated in the retentate solution. 10 refs., 5 figs., 5 tabs.« less

  • ; ; ; ... - Separation Science and Technology; (United States)
    Ligand-modified micellar-enhanced ultrafiltration (LM-MEUF) is a membrane-based separation technique which can selectively remove specific ions from an aqueous solution containing several ions of like charge. In LM-MEUF, surfactant and amphiphilic ligand are added to the contaminated water. The surfactant forms aggregates called micelles, and the ligand is selected to complex the ion of interest and to solubilize strongly in the micelles. The result is micelles containing a high fraction of the ligand and the target ion. If the surfactant is chosen to have the same charge as the target ion, other ions in solution with this same charge will notmore » associate with the micelles, making the retention of ions by the micelles very selective. The solution is then passed through an ultrafiltration membrane with pore sizes small enough to block the passage of micelles. In this study, divalent copper is the target ion in a solution also containing divalent calcium. A cationic surfactant is used with N-n-dodecyl-iminodiacetic acid as the copper-specific ligand. Rejections of copper of up to 99.2% are observed, with no rejection of calcium, showing that LM-MEUF has almost perfect selectively, as well as high capacity in this case.« less