Study of adsorption performance and adsorption mechanism for U(VI) ion on modified polyacrylonitrile fibers

The modified polyacrylonitrile fibers (ACPAN fibers) was synthesized by oximation reaction and alkaline hydrolysis. ACPAN fibers was characterized by means of SEM, FTIR, XPS and elementary analysis. The effects of contact time, solid–liquid ratio, pH, ionic strength, initial concentration and temperature on U(VI) adsorption onto ACPAN fibers was studied and the adsorption mechanism was also discussed. The experimental data fitted well pseudo-second-order kinetics model and Freundlich and D–R models, and thermodynamic process was an endothermic and spontaneous reaction. The maximum adsorption capacity was 163 mg/g, and U(VI) and ACPAN fibers possible formed more stable penta-coordination complexation. This paper highlighted ACPAN fibers as a good adsorbent to remove efficiently and economically uranyl from radioactive wastewater.