Use of Nickel Sulphide–PMMA Composite Beads for Removal of ¹⁰⁶Ru from Alkaline Radioactive Liquid Waste

Abstract

Use of NiS coprecipitation was found to be very effective at a concentration level of 2500 ppm of Ni⁺² and 1300 ppm of S⁻² for the effective removal of ¹⁰⁶Ru from the effluent stream. However, the NiS precipitate increases the sludge volume. Efforts were made to form the composite material of NiS in combination with Poly methyl metha acrylate (PMMA) polymer beads. The NiS–PMMA composite beads were loaded in a column and its ruthenium uptake behavior was studied. The NiS–PMMA beads were found to be functioning satisfactorily in alkaline conditions. It has shown a K_d value of about 8000–9000. The NiS–PMMA composite material has also shown the potential for the uptake of ¹²⁵Sb. The effect of salt concentration on the K_d value is negligible. The equilibrium conditions are achieved in around 25–30 min in batch mode of operation. The composite material can be suitably used in the column mode of operation.

Keywords:

• ion exchange
• nickel sulphide
• polymethyl metha acrylates
• resorcinol formaldehyde (RF) resin
• ruthenium

ACKNOWLEDGEMENT

The authors extend their gratitude towards Shri. R.K. Mishra and Dr. J.G. Shah for providing analytical support for the physical characterization of the NiS powder material using XRD and SEM techniques. Authors are also thankful to Shri. R. D. Changrani, Chief Superintendent, NRGF (T), for his guidance and interest in the work.