Microcapsules containing ionic liquid [A336][P507] for La~(3+)/Sm~(3+)/Er~(3+)recovery from dilute aqueous solution

The efficacy of polysulfone microcapsules encapsulating ionic liquid trialkylmethylammonium]di(2-ethylhelxyl) orthophosphinate](A336]P507]) for the extraction of La~(3+), Sm~(3+) and Er~(3+) from dilute aqueous solutions was investigated. Microcapsules were synthesized using coaxial microfluidic method, and subsequently encapsulated with extractant A336]P507]. The kinetics data were fitted well by pseudo-second-order equation and Crank model, and the kinetics parameters were evaluated. The extraction rate had the order of Er~(3+)Sm~(3+)La~(3+). The isotherm data were analyzed by Langmuir model and shifted Langmuir model. The extraction capacities of La~(3+), Sm~(3+) and Er~(3+) were 58.4, 56.6 and 81.7 mg/g, respectively. The dependency of stripping performance on HNO3 concentration was measured. The regeneration of microcapsules was evaluated using cycling extraction experiments.