Synthesis of sodium alginate (SA)/ polyvinyl alcohol (PVA)/ polyethylene oxide (PEO)/ ZSM-5 zeolite hybrid nanostructure adsorbent by casting method for uranium (Ⅵ) adsorption from aqueous solutions

摘要

In this article, sodium alginate/polyvinyl alcohol/polyethylene oxide/ZSM-5 zeolite (SA/PVA/PEO/ZSM-5) nanohybrid adsorbent was produced with the casting technique and adsorption of uranium ions from aqueous solutions was scrutinized with it. The effects of several batches adsorption parameters such as zeolite content, acidity, adsorbent content, contact time, initial concentration, and temperature were investigated. The kinetic data were analyzed with various kinetic models. The results demonstrated that experimental data were fitted well by the double-exponential kinetic model. The equilibrium data were described thanks to the Freundlich, Langmuir, and Dubinin-Radushkevich isotherm models. The maximum adsorption capacity of uranium ions was found to be 92.76 mg g-1 at a pH of 5.0 and a temperature of 45 ?C. The obtained thermodynamic and DubininRadushkevich parameters indicated that the physical sorption of uranium onto the SA/PVA/PEO/ZSM-5 adsorbent was dominant. Furthermore, the SA/PVA/PEO/ZSM-5 nanohybrid adsorbent was regenerated by HCl/HNO3, and then after five steps of adsorption-desorption cycles, the adsorption capacity was changed less than 20%.