NOPR Collection:

Synthetic, analytical and kinetic studies on a cadmium selective phase of zirconium (IV) tungstophosphate cation exchanger

Sat, 01 Nov 1997 00:00:00 GMT

Title: Synthetic, analytical and kinetic studies on a cadmium selective phase of zirconium (IV) tungstophosphate cation exchanger Authors: Varshney, K G; Khan, Asif Ali; Niwas, Ram; Parashar, P K; Nasim, K T Abstract: A new phase of zirconium (IV) tungstophosphate cation exchanger has been synthesized and characterized with the help of ion exchange, IR, TGA and DTA studies. The ion exchange and distribution studies indicate that the material is highly selective for cadmium. On this basis some binary separations such as Cd(II)-Zn(II), Cd(II)-HG(II) and Cd(II)-Sr(II) have been performed on its column. Kinetics of exchange of alkaline earth metal ions on this material has also been studied to understand its exchange behaviour. Page(s): 317-323

Use of type-II strong base anion exchange resins for ion exchange chromatographic separation of isotopes of boron

Sat, 01 Nov 1997 00:00:00 GMT

Title: Use of type-II strong base anion exchange resins for ion exchange chromatographic separation of isotopes of boron Authors: Sharma, B K; Rajamani, P; Mathur, P K Abstract: The optimum conditions for the regeneration of strong base anion exchange resins of type-I and type-II were determined for cost - effective separation of isotopes of boron by ion exchange chromatography. The possibility of using unspent alkali content of the effluent was also exploited. Removal of carbonate impurity from Rayon grade caustic lye (used as regenerant after dilution) and recycling of Ba(OH)₂ was studied to avoid waste disposal problems. The determination of (i) ion exchange capacity of Duolite-162 resin for hydroxyl - chloride and hydroxyl - borate exchanges, (ii) isotopic exchange separation factor by batch method and (iii) effect of concentration of boric acid (in presence and absence of mannitol) on isotopic exchange separation factor to test the suitability of the type-II resin for this process are discussed. Page(s): 308-316

Empirical modelling of U(IV) third phase formation in 30% TBP/n-dodecane system

Sat, 01 Nov 1997 00:00:00 GMT

Title: Empirical modelling of U(IV) third phase formation in 30% TBP/n-dodecane system Authors: Kumar, Shekhar Kumar; Koganti, S B Abstract: Formation of second organic phase due to limiting solubility of tetravalent actinide solvates in organic solvent has been studied in a qualitative manner by several researchers. Quantitative relations for interactions among various solutes for second organic phase formation were not reported in open literature. In this contribution, an empirical model for U(IV) third phase formation in biphasic U(NO₃)₄-H₂O-HNO₃-30% TBP/n-dodecane system has been reported. Empirical models were also developed for correlating various third phase characteristics like temperature dependency of third phase formation, volume and concentration of constituents-U (IV) and TBP. Performance of the reported models has been compared with models previously reported. Page(s): 303-307

Investigations of leachability characteristics of metal contaminants from plating and galvanising solid wastes by TCLP

Sat, 01 Nov 1997 00:00:00 GMT

Title: Investigations of leachability characteristics of metal contaminants from plating and galvanising solid wastes by TCLP Authors: Singh, I B; Mudgal, M; Mishra, Alka; Dawar, Divya; Chakradhar, B Abstract: In the present investigation, Toxicity Characteristics· Leaching Procedure (TCLP) has been employed to investigate the leachability characteristics of metal contaminants from plating and galvanising wastes. Atomic absorption spectroscopy (AAS) analysis of extracts of Cr-plating waste indicates that leachability of Cr, Fe, Pb and Mn in secondary extract is high as compared to primary extract. Occurrence of notably high concentration of Zn and Fe in primary extract of galvanising waste suggests their immediate leachability in s6il. Toxicity due to Pb and Mn of plating and galvanising waste is expected to be quite high in immediate and long-term duration because of their significant leachability in primary and secondary extract. With an increase of temperature from 30 to 60°C, the leachability of Cr from plating waste and Zn from galvanising waste increases significantly while a slight increase of leachability of Fe, Pb and Mn is noticed in both wastes. Page(s): 298-302