On the Potential of a Poly(vinylidenefluoride-co-hexafluoropropylene) Polymer Inclusion Membrane Containing Aliquat® 336 and Dibutyl Phthalate for V(V) Extraction from Sulfate Solutions

Abstract

A polymer inclusion membrane (PIM) composed of 50 wt% base polymer poly(vinylidenefluoride-co-hexafluoropropylene), 40 wt% extractant Aliquat® 336, and 10 wt% dibutyl phthalate as plasticizer/modifier provided the efficient extraction of vanadium(V) (initial concentration 50 mg L−1) from 0.1 M sulfate solutions (pH 2.5). The average mass and thickness of the PIMs (diameter 3.5 cm) were 0.057 g and 46 μm, respectively. It was suggested that V(V) was extracted as VO2SO4− via an anion exchange mechanism. The maximum PIM capacity was estimated to be ~56 mg of V(V)/g for the PIM. Quantitative back-extraction was achieved with a 50 mL solution of 6 M H2SO4/1 v/v% of H2O2. It was assumed that the back-extraction process involved the oxidation of VO2+ to VO(O2)+ by H2O2. The newly developed PIM, with the optimized composition mentioned above, exhibited an excellent selectivity for V(V) in the presence of metallic species present in digests of spent alumina hydrodesulfurization catalysts. Co-extraction of Mo(VI) with V(V) was eliminated by its selective extraction at pH 1.1. Characterization of the optimized PIM was performed by contact angle measurements, atomic-force microscopy, energy dispersive X-ray spectroscopy, thermogravimetric analysis/derivatives thermogravimetric analysis and stress–strain measurements. Replacement of dibutyl phthalate with 2-nitrophenyloctyl ether improved the stability of the studied PIMs.

Membrane extraction of V(V) by an oleic acid plasticized poly(vinyl chloride)/Aliquat® 336 polymer inclusion membrane

“…Polyvinyl chloride base polymer, the extractant Aliquat® 336, and the plasticizer in various proportions with a total mass of 1 g were weighed into a glass jar. A volume of 11 ml THF was used to dissolve the membrane constituents 23 . After 2 h stirring of the mixture with a magnetic stirrer at room temperature, it was stirred for a further 2 h at 40°C until all components were thoroughly dissolved.…”

“…A volume of 11 ml THF was used to dissolve the membrane constituents. 23 After 2 h stirring of the mixture with a magnetic stirrer at room temperature, it was stirred for a further 2 h at 40 C until all components were thoroughly dissolved. The resulting solution was poured into a glass petri dish (internal diameter 7 cm).…”

“…It has been employed as a plasticizing agent for fabrication of the membrane La(III) ion-selective electrode. 22 We have recently involved with the application of a variety of polymer inclusion membranes for the extraction-recovery of V(V), 5,20,23 Cr(VI) 18 and Bi(III). [24][25][26] The PIMs composed of poly(vinylidenefluoride-cohexafluoropropylene)/trihexyltetradecylphosphonium chloride/2-nitrophenyloctyl ether (PVDF-HFP/ Cyphos ® IL101/NPOE), 20 and poly(vinylidenefluorideco-hexafluoropropylene)/tricaprylmethylammonium chloride/dibutyl phthalate (PVDF-HFP/Aliquat ® 336/DBP) 23 exhibited interesting results for the extraction-separation of V(V).…”

“…22 We have recently involved with the application of a variety of polymer inclusion membranes for the extraction-recovery of V(V), 5,20,23 Cr(VI) 18 and Bi(III). [24][25][26] The PIMs composed of poly(vinylidenefluoride-cohexafluoropropylene)/trihexyltetradecylphosphonium chloride/2-nitrophenyloctyl ether (PVDF-HFP/ Cyphos ® IL101/NPOE), 20 and poly(vinylidenefluorideco-hexafluoropropylene)/tricaprylmethylammonium chloride/dibutyl phthalate (PVDF-HFP/Aliquat ® 336/DBP) 23 exhibited interesting results for the extraction-separation of V(V). However, using a cost-effective base polymer than PVDF-HFP, on one hand, and a greener plasticizer, on the other hand, convinced us to follow the preparation of a PVCbased PIM containing Aliquat ® 336 as extractant and oleic acid as the green plasticizing agent.…”

Thorium Removal, Recovery and Recycling: A Membrane Challenge for Urban Mining

“…The analysis of the processes in which the minerals or waste containing thorium are processed shows that the classic technologies have material losses in the environment, which could be reduced with or through membrane techniques [ 232 , 233 , 234 , 235 , 236 , 237 , 238 , 239 , 240 , 241 , 242 , 243 , 244 , 245 , 246 , 247 , 248 , 249 , 250 , 251 , 252 , 253 , 254 , 255 ]. Thus, in the classical thorium recovery technologies, some disadvantages [ 1 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65…”