Comparative evaluation of actinide ion uptake by polymer inclusion membranes containing TODGA as the carrier extractant

• Published in: Journal of hazardous materials 2014-06, Vol.275, p.146-153
• Main Authors: Mahanty, B.N., Raut, D.R., Mohapatra, P.K., Das, D.K., Behere, P.G., Afzal, Md
• Format: Article
• Language: English
• Subjects: Actinides; Actinoid Series Elements - chemistry; Applied sciences; Carriers; Cellulose - analogs & derivatives; Cellulose - chemistry; Diglycolamide; Exact sciences and technology; Glycolates - chemistry; Inclusions; Membranes; Membranes, Artificial; Nitric acid; Nitrobenzenes - chemistry; Plasticizers - chemistry; Pollution; Polymer inclusion membrane; Powder injection molding; TODGA; Transport; Uptakes
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2014.04.059

•PIMs containing TODGA were used for actinide ion uptake and transport.•The trend of uptake was: Am3+>Pu4+>Th4+>UO22+.•The transport trend was similar though significant amount was held in the PIM.•The diffusion coefficients were lower than those obtained with SLM. Polymer inclusion membranes (PIM) containing TODGA (N,N,N′,N′-tetra-n-octyl diglycolamide) were evaluated for the separation of actinide ions such as Am3+, Pu4+, UO22+ and Th4+ from acidic feeds. The PIMs were prepared using cellulose triacetate (CTA) as the polymer matrix and 2-nitrophenyloctyl ether (NPOE) as the plasticizer along with the diglycolamide carrier extractants and were characterized by conventional techniques such as XRD, thermal analysis and AFM. The PIM composition was optimized by a series of studies which involved variation in the CTA, NPOE and carrier concentration which suggested 58% TODGA, 30% NPOE and 12% CTA to be optimum. The uptake studies were carried out using feed solutions containing varying concentrations of nitric acid and showed the trend: Am3+>Pu4+>Th4+>UO22+. Transport studies were carried out in a two-compartment cell where nitric acid concentration the feed was varied (1–3M) while the receiver compartment contained alpha-hydroxy-iso-butyric acid (AHIBA). The actinide ion transport efficiencies with TODGA containing PIMs followed the same trend as seen in the uptake studies. The AFM patterns of the PIMs changed when loaded with Eu3+ carrier (used as a surrogate for Am3+) while the regenerated membranes have displayed comparable morphologies. Diffusion coefficient values were experimentally obtained from the transport studies and were found to be 8.89×10−8cm2/s for Am3+ transport.