Selective Uptake and Recovery of Palladium by Biopolymer Microcapsules Enclosing Cyanex 302 Extractant

• Published in: Journal of nuclear science and technology Vol. 38; no. 5; pp. 342 - 348
• Main Authors: MIMURA, Hitoshi, OHTA, Hiroshi, AKIBA, Kenichi, ONODERA, Yoshio
• Format: Journal Article
• Language: English
• Published: Tokyo Taylor & Francis Group 01.05.2001; Atomic Energy Society of Japan
• Subjects: alginate; Applied sciences; biopolymer; Biopolymers; breakthrough curve; chromatographic separation; Column chromatography; Cyanex 302; distribution coefficient; Energy; Exact sciences and technology; extraction columns; Fuels; isotherm; Isotherms; Langmuir Blodgett films; microcapsule; Nuclear fuels; palladium; Pollution; Positive ions; Preparation and processing of nuclear fuels; Radioactive wastes; recovery; separation factor; uptake; Waste utilization; Wastes; Material recovery; Phosphinic acids; Ruthenium; Biopolymer; Microcapsule; High level radioactive waste; Nuclear fuel; Palladium; Solvent extraction; Reprocessing; Irradiated nuclear fuel
• ISSN: 0022-3131; 1881-1248
• DOI: 10.1080/18811248.2001.9715038

Selective uptake and recovery of platinum group metals are an important subject in the high level liquid waste treatment. An extractant having a strong affinity for palladium, bis(2,4,4-trimethylpentyl) monothiophosphinic acid (Cyanex 302, HA), was enclosed into microcapsules by utilizing highly immobilizing ability of biopolymer (alginate and alginic acid gel polymers). The uptake of Pd 2plus , Ru(NO) 3+ and Rh 3+ for granular microcapsules has been studied by batch and column methods. A relatively large distribution coefficient of Pd 2plus , K d,Pd , of above 10 4 cm 3 /g was obtained in the presence of 0.2-0.5 M HNO 3 and the separation factors of Pd/Ru and Pd/Rh were estimated to be above 10 2 . The uptake of Pd 2+ on microcapsules followed a Langmuir-type uptake isotherm and the maximum uptake capacity was estimated to be 0.72-0.96 mmol/g. These metal cations were chromatographically separated through the column packed with HA-alginate microcapsules.