Acrylonitrile-Structured Ternary Co-oligomers of 4-Isopropenylphenol, Phenol, and Formaldehyde as Sorbents for Recovery of Uranyl Ions from Aqueous Systems

Abstract

Triple co-oligomers of 4-isopropenylphenol, phenol and formaldehyde were synthesized and used for the first time as precursors in the structuring reaction in the presence of acrylonitrile and the initiator benzoyl peroxide. The yield of cross-linked copolymers is 84% (of theory). The use of hydrolyzed cross-linked copolymers is shown to be effective as sorbents for the extraction of UO22+ ions from model aqueous systems under batch conditions, and the degree of their sorption significantly depends on the medium pH, the initial concentration of UO22+ ions and the exposure time. The best results were achieved at pH 7 and 9, at which the degree of extraction of UO22+ ions from an aqueous solution with their initial concentration of 134 ± 0.5 mg L–1 is ~93.5% (room temperature, 24 h), while the sorption capacity of the cross-linked copolymer is ~210 mg g–1. The highest sorption capacity of the copolymer reaches 300 ± 30 mg g–1. The possibility of regeneration of the sorbent with mineral acid (НNO3, HCl) was revealed; the maximum degree of desorption of UO22+ ions is ~91%.