Preparation method and application of algae magnetic cationic exchange resin

The invention relates to a method for preparing a magnetic biomass cationic exchange resin from algae plants mainly. The method comprises the following steps: performing centrifugal treatment on collected algae, drying by a freeze drying mode, grinding the dried algae into powder, and mixing the algae powder with a Fe /Fe mixed solution, thereby obtaining an intermediate reactant; adding an ammonia water solution, stirring, mixing for reacting in an anaerobic environment for 1-8 hours, washing the mixture by deionized water, performing suction filtration and vacuum drying, and screening and grading to remove iron oxides and other impurities, thereby obtaining the algae magnetic cationic exchange resin. The method has the advantages that the raw materials are readily available and are low in cost, the solid-liquid separation is convenient, the mechanical strength of the algae resin is greatly improved, the wear resistance of the resin is enhanced, and as no organic matter is dissolved out, secondary pollution to a water body is avoided.