Adsorptive removal of technetium-99 using macroporous poly(GMA-co-EGDMA) modified with diethylene triamine

摘要

The possibility of sorption of technetium-99 in the form of pertechnetate anion (TcO_4~-) and the sorption kinetics for removing TcO_4~- from aqueous solution by chelating polymers based on glycidyl methacrylate (GMA) were investigated. Two samples of macroporous crosslinked poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) (PGME), with different amount of the crosslinker (ethylene glycol dimethacrylate, EGDMA), were synthesized by suspension copolymerization and functionalized with diethylene triamine (deta). We propose that nonspecific sorption of pertechnetate anion via electrostatic interactions takes place at the protonated amino groups of macroporous crosslinked copolymer. The results of batch experiments performed at pH 1-14 showed fast sorption kinetics for removing TcO_4~- by amino-functionalized PGME-deta in a wide range of pH, that is, from 1.0 to 9.0. Almost complete removal of TcO _4~- (91-98%) was reached within 180 min in the stated pH range (1.0-9.0), with the sorption half-times of under 25 min. The partitioning coefficients of linear adsorption isotherms, with 180-min equilibrium time, reach the high values of 2130 mL g~(-1) and 1698 mL g~(-1) for the two samples of synthesized PGME-deta.