A strategy for effective cesium adsorption from aqueous solution by polypentacyanoferrate-grafted polypropylene fabric under γ-ray irradiation

Abstract For both cesium resources and human health, it is crucial to develop novel materials for effective separation of cesium from aqueous solutions. We report herein a new approach to separate cesium from aqueous solutions using poly(pentacyanoferrate)-functionalized polypropylene nonwoven fabric. To obtain the adsorbent, poly(4-vinyl pyridine) (P4VP) was first grafted onto polypropylene nonwoven fabric under γ-ray irradiation, and then reacted with sodium pentacyanoaminoferrate. Adsorption kinetically follows a pseudo-second-order model and achieves equilibrium within 24 min at pH 7.0 and 298.15 K. To the best of our knowledge, it is the fastest adsorption of cesium ions from aqueous solution till now. The maximum adsorption capacity calculated from Langmuir equation was 47.4 mg/g with high selectivity. Adsorption mechanism involves the formation of coordination and covalent bond between cesium and cyano group. In addition, the adsorbent could be regenerated effectively after four cycles with 0.1 M NaOH as a desorbing agent. It is noticed that the covalent combination of functional ligands with nonwoven fabric may improve the practical operability in comparison with nano-adsorbents. This work indicates that the functional fabric may be a promising adsorbent to achieve effective removal of cesium ions from aqueous solutions.