Highly efficient removal of uranium(VI) from aqueous solutions by poly(acrylic acid-co-acrylamide) hydrogels

In this study, poly(acrylic acid-co-acrylamide) (PAAAM) hydrogels were used to remove uranium (VI) ions in wastewater and characterized by FTIR, SEM, EDX. The effects of pH value, coexistence of ionic strength, contact time, initial U (VI) ion concentration and adsorption temperature were also studied. Adsorption data fitted well with pseudo-second-order, intra-particle diffusion model and Langmuir isotherm mode, the maximum adsorption capacity of U(VI) was 713.24 mg g−1. Thermodynamic analysis shows that the adsorption of U(VI) is spontaneous endothermic. PAAAM hydrogel has excellent regeneration performance, after five time adsorption–desorption cycles, the adsorbent still maintained 99.24% adsorption capacity.