Carboxymethyl Cellulose/Polyacrylamide/Fe₃O₄ Magnetic Ion Imprinting Biosorbent for Removal and Recovery of La³

To use resources rationally, the recovery and recycling of rare earth (RE) from industrial sewage have attracted a lot of attention. Herein, a polymer adsorbent CMC/PAM/Fe₃O₄ (CPF) was synthesized from renewable carboxymethyl cellulose (CMC), polyacrylamide (PAM), and Fe₃O₄ by the template of La³⁺ using ion imprinting technology. The CPF was characterized with X-ray diffraction (XRD), IR, X-ray photoelectron spectroscopy (XPS), and scanning electron microscope (SEM), and results show that PAM and CMC can crosslink with each other and form copolymers with Fe₃O₄ particles dispersing in it. The adsorption properties for the template ions La³⁺ were fully studied. It is found that CPF exhibited good adsorption performance with an adsorption capacity of 34.6 mg·g^-1. Cycling experiments show that CPF still has high efficiency even after 5 cycles. Meanwhile, the desorption rate can reach more than 98%. The low wastage and high adsorption/desorption efficiency would enable CPF to be a good candidate adsorbent for removal/recovery of La³⁺ from industrial sewage.