Adsorption of UO22+ from aqueous solution onto copolymers of styrene and maleic anhydride

The copolymers of styrene and maleic anhydride resin (PSt/MA) was synthesized by free radical polymerization and characterized by means of FTIR. It is shown that the PSt/MA copolymer has rather strong coordination ability to UO2 (2+) ions by chelation with the carboxylate group, and the microstructures of the U(VI)-PSt/MA complexes can be well controlled. The influence factors on UO2 (2+) ions were also investigated and described in detail, such as contact time, solid/liquid ratio, pH value, ethanol content, and initial concentration. It was found that the maximum adsorption quantity of UO2 (2+) was 831 mg/g. Experiments show that PSt/MA can recover UO2 (2+) ions with high adsorption selectively from a simulated industry solution containing Ca2+ and Mg2+ as impurities. The adsorption kinetic data were best described by the pseudo-second-order equation, indicating that the chemical adsorption was the rate-limiting step. And there are very good correlation coefficients of linearized equations for Langmuir model, which indicated that the sorption isotherm of the PSt/MA for UO2 (2+) can be fitted to the Langmuir model. After five times of repeated tests for the hydrogel it still remained its excellent adsorption.