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 181.8mg g−1. The pseudo-second-order model (R...