Highly Efficient Removal of Uranium(VI) From Aqueous Solution Using the Polyethyleneimine Modified Magnetic Chitosan

In this study, Polyethyleneimine modified magnetic chitosan (MCS-PEI) was synthesized by grafting polyethyleneimine onto chitosan and adding magnetic Fe3O4 with sodium polyphosphate as crosslinking agent. The structure of the prepared material was characterized by FT-IR, SEM, EDS, XRD and XPS, which showed MCS-PEI was successfully synthesized. After a series of single factor experiments, the adsorption data fitted well with the Langmuir model (R2 = 0.99), being the maximum adsorption capacity equal 181.8 mg g−1. The pseudo-second-order model (R2 = 0.997) and Dubinin-Radushkevich model (R2 = 0.9598) indicated that the adsorption process was chemical adsorption. And thermodynamic studies showed that the adsorption was spontaneous and exothermic. The adsorption rate decreased by no more than 4% after the four adsorption–desorption experiments. This work illustrates that MCS-PEI is an environmental friendly, efficient and low-cost adsorbent.