J.V. Sonawane

Pseudo-Emulsion Based Hollow Fiber Strip Dispersion Technique (PEHFSD): Optimization, Modelling and Application of PEHFSD for Recovery of U(VI) from Process Effluent

Abstract Pseudo emulsion based hollow fiber strip dispersion technique (PEHFSD) is the first of its kind ever explored in radioactive environment for the extraction of uranium from acidic process streams. Permeation of U(VI) was investigated as a function of various experimental variables such as hydrodynamic conditions (flow rates of pseudo-emulsion and feed phase), concentration of U(VI) in the feed phase, concentration of tri-n-butylphosphate (TBP), HNO3 concentration in feed phase, O/A ratio and 0.01 M HNO3 as stripping agent in pseudo-emulsion phase. The mass transfer coefficient was calculated from the experimental results and a model has been presented for determining mass transfer characteristics. PEHFSD has been demonstrated for separation/recovery of uranium from oxalate supernatant waste generated during plutonium precipitation by oxalic acid. PEHFSD and HFSLM (hollow fiber supported liquid membrane) performance has been compared in order to analyze the efficiency of the technique.

Pseudo-emulsion based hollow fibre strip dispersion (PEHFSD) technique for permeation of Cr(VI) using Cyanex-923 as carrier

Pseudo-emulsion based hollow fibre strip dispersion (PEHFSD) technique is investigated for the permeation-separation of chromium from hydrochloric acid media. The permeation of Cr(VI) is investigated in relation to various experimental variables: hydrodynamic conditions, the concentration of Cr(VI) and HCl in the feed phase, Cyanex-923 concentration, hydrazine sulphate as the stripping agent in the pseudo-emulsion phase. The performance of the PEHFSD was analyzed and optimum conditions are suggested for chromium separation from simulated industrial waste in a hydrochloric acid media.

Application of Hollow Fiber Contactor in Nondispersive Solvent Extraction of Pu(IV) by TBP

Abstract Data on dispersion‐free solvent extraction (DFSX) of Pu(IV) from acidic nitrate media using microporous hydrophobic polypropylene hollow fiber membrane contactor with tri‐n‐butylphosphate (TBP) employing as an extractant are being presented. The DFSX operation was carried out with various concentration of TBP in n‐dodecane by passing acidic feed containing Pu (IV) through the tube side at the flow rate of 5.83 cm3 s−1 and organic extractant through the shell side at the flow rate of 1.53 cm3s−1. Extraction studies were performed under different hydrodynamic conditions and the overall mass‐transfer coefficient was evaluated with countercurrent flow condition. It was possible to extract and concentrate Pu(IV) from aqueous phase by employing this technique. For back extracting the Pu, uranous nitrate and hydroxylamine hydrochloride solution as strippants were examined, which flowed through the tube side (flow rate: 6.11 cm3 s−1) and the loaded organic was passed through the shell side with the flow rate of 1.66 cm3s−1. Results revealed that ∼80% of Pu(IV) from oxalate supernatant waste could be extracted by utilizing this technique.

Separation of Uranium and Plutonium from Aqueous Acidic Wastes Using a Hollow Fiber Supported Liquid Membrane

Abstract The use of microporous hydrophobic polypropylene, as a hollow fiber supported liquid membrane (HFSLM) was considered for removal of actinides such as uranium (U) and plutonium (Pu) from nuclear process effluents. The 1.09 M extractant, tri‐n‐butyl phosphate (TBP) diluted with n‐dodecane was used as carrier. The study includes the hydrodynamic and chemical parameters. Modeling was performed using chemical parameters and rate controlling steps were identified. It was possible to remove U(VI) and Pu(IV) from process effluent more than 99% in presence of fission products. The optimum effective feed linear flow velocity was found to be 0.88 cm sec−1. The stripping reagent 0.1 M hydroxylamine hydrochloride (NH2OH · HCl) in 0.5 M HNO3 was used. The permeation of metal ions increased with increasing effective surface area and model for higher concentration of metal ion was able to describe the transport mechanism of U(VI).