Search Results

You are looking at 1 - 7 of 7 items for

  • Author or Editor: R. Bhanushali x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract  

As a part of treatment of low level active waste, co-precipitation of plutonium (Pu) and americium (Am), with thorium oxalate, from oxalate supernatants generated during plutonium oxalate precipitation has been investigated. A simple method for the simultaneous removal of both Pu and Am from oxalate supernatants could be developed. This simple process achieves incorporation of these alpha active nuclides into small volumes of solid matrix from large volumes of aqueous waste.

Restricted access

Abstract  

Synthetic inorganic exchangers exhibit good thermal and radiation stability. Thorium oxalate precipitate shows potential for co-precipitation of plutonium and americium from oxalate supernatant generated during plutonium oxalate precipitation. In the present study, efforts were made to prepare thorium oxalate precipitate to be used for column operation. Distribution ratios were determined to optimize conditions for sorption of plutonium and americium on thorium oxalate from nitric acid + oxalic acid solutions with composition similar to that of oxalate supernatant. Column experiments were also performed to evaluate the sorption capacity of thorium oxalate for plutonium and americium from the same medium. The result showed that, thorium oxalate prepared in 1.75M HNO3 at 70 °C is suitable for column operations. These studies showed that plutonium and americium could be simultaneously removed from aqueous solutions with composition similar to plutonium oxalate waste using glass column packed with thorium oxalate and these nuclides could be recovered by eluting with 3M HNO3.

Restricted access

Abstract  

A new ion exchange material prepared by impregnating Aliquat-336 on silica-gel has been investigated for the recovery of plutonium from nitric-oxalic acid solutions. The distribution ratio of Pu(IV) was studied at various concentrations of nitric and oxalic acids. The presence of Al(III) and Fe(III) in the solution, enhances the uptake of Pu(IV). Pu(IV) breakthrough capacities (btc) have been determined using 2.5 ml bed of the ion exchange material column in the absence and the presence of Al(III) and Fe(III) nitrate. The elution behavior of Pu(IV) was also studied using nitric acid solutions containing reducing agents. More than 90% of plutonium could be recovered from nitric-oxalic acid solutions.

Restricted access

Abstract  

Porous zirconia spherical particles have been prepared by internal gelation process. During preparation of these spherical particles, a cationic surfactant, cetrimide was added in the feed broth to increase the surface area and porosity of the particles. The sorption behavior of plutonium was investigated on this material from different complexing aqueous media from the recovery point of view. Distribution ratio studies have been carried out to investigate the effect of varying concentrations of oxalic acid, phosphoric acid, sulphuric acid, nitric acid, sodium carbonate and sodium bicarbonate to optimize the conditions of sorption of plutonium on this ion exchange material.

Restricted access

Abstract  

Sorption of Pu(IV) on alumina microspheres prepared by the sol-gel procedure has been investigated for the recovery of plutonium from nitric acid-oxalic acid solutions. Distribution ratio for Pu(IV) between alumina microspheres and nitric acid-oxalic acid have been determined. The influence of the mode of preparation and heat treatment of these microspheres, on the sorption of Pu(IV) have been investigated. Pu(IV) breakthrough capacities have been determined using a 5 ml bed of alumina with solutions of Pu(IV) in 1M HNO3+0.05M H2C2O4 and 0.5M HNO3+0.05M H2C2O4. The elution behavior of Pu(IV) loaded on these microspheres were studied using nitric acid solutions containing different oxidising and reducing agents. Investigations were also carried out to fix the activity in the alumina matrix by heat treatment.

Restricted access

Abstract  

Spherical beads of titania were prepared by a sol-gel route. During the preparation a cationic surfactant was added in the feed broth to modify the surface characteristics of the microspheres. The absorption behavior of Pu(IV) from carbonate medium on these microspheres was studied by batch experiments. Loading and elution behavior of Pu(IV) on a bed of titania microspheres was studied and the practical capacity was determined.

Restricted access