Technetium(VII) transport across supported liquid membranes (SLMs) containing 2-nitrophenyl octyl ether (NPOE)
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J. Chen
Technetium is one of key issues in the treatment of radioactive liquid waste because of its long half-life in combination with high fission yield and its geochemical mobility. For the removal of Tc(VII) from water and concentrated alkaline solutions, 2-nitrophenyl octyl ether (NPOE) is a very effective extractant. In this paper we describe the application of supported liquid membranes (SLMs) impregnated with NPOE for the removal of Tc(VII) from these solutions by using 1.5 M HNO3 receiving phase solutions. Transport of Tc(VII) across a SLM was evaluated with a mechanistic model using a permeability coefficient P to describe the rate of transport. SLM transport of Tc(VII) with NPOE is completely membrane diffusion limited and that there are no aqueous resistances. The membrane diffusion coefficient Dm was calculated to be Dm=6.4×10-13 m2/s. Permeability is highest for transport from pure water source solution, with P = 3.2×10-4 cm/s. From NaOH solutions the permeability decreases slightly. For acidic source phase the permeability is even lower due to the poor extraction yields of Tc(VII) from acidic solutions into NPOE. Counter current transport of H+ does not affect the extraction and permeability. The Tc(VII)-NPOE system is very robust, only small quantities of NPOE are needed, and the membrane distribution and permeability coefficients are sufficiently large for practical applications.
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- Uranyl(VI) carbonate complex formation: Validation of the Ca2UO2(CO3)3(aq.) species
- The migration of radionuclides 237Np, 238Pu and 241Am in a weak loess aquifer: A field column experiment
- Technetium(VII) transport across supported liquid membranes (SLMs) containing 2-nitrophenyl octyl ether (NPOE)
- Radiotracer study of the electrophoretic behavior of Eu and its complexes with humic acid
- Electroosmotic effects in the determination of ion mobilities of carrier-free radionuclides in free aqueous electrolyte solutions
Articles in the same Issue
- Determination of cumulative yields of fission products from 238U by 5.0 MeV neutrons
- Plutonium(IV) peroxide formation in nitric medium and kinetics Pu(VI) reduction by hydrogen peroxide
- Thermodynamics of the PuO2+-Na+-OH--Cl--ClO4--H2O system: use of NpO2+ Pitzer parameters for PuO2+
- Interaction of aerobic soil bacteria with plutonium(VI)
- Complexation behaviour of neptunium with humic acid
- Uranyl(VI) carbonate complex formation: Validation of the Ca2UO2(CO3)3(aq.) species
- The migration of radionuclides 237Np, 238Pu and 241Am in a weak loess aquifer: A field column experiment
- Technetium(VII) transport across supported liquid membranes (SLMs) containing 2-nitrophenyl octyl ether (NPOE)
- Radiotracer study of the electrophoretic behavior of Eu and its complexes with humic acid
- Electroosmotic effects in the determination of ion mobilities of carrier-free radionuclides in free aqueous electrolyte solutions
