Adsorption properties of magnetic sodium ferrosilicate/carboxymethyl chitosan composite with more functional groups and surface negative potential

The carboxymethyl chitosan and sodium ferrosilicate were successfully combined and magnetized by the hydrothermal method, and then citric acid was used as a dispersant to further modify the composite material, effectively avoiding the aggregation effect of the material. The composite material showed a large adsorption capacity (515.0 mg g −1 ) for methylene blue (MB). The composite materials were characterized by XRD, SEM, EDX, FTIR, VSM, BET, Zeta and other characterization methods. The results showed that the composite with citric acid as dispersant had a larger specific surface area and a richer pore structure, and the negative potential on the surface of the composite material made it more conducive for the adsorption of cationic dye MB. The Langmuir model and the pseudo second-order kinetic model were used to explain the process of composite material adsorption of MB. In addition, the composite material had good recycling and reuse characteristics, and had great application value in the field of wastewater treatment. • Combination and magnetization of carboxymethyl chitosan and sodium ferrosilicate by hydrothermal method. • The adsorbent has excellent adsorption performance and is easy to recover. • The influence of adsorbent dosage, pH and other factors on the adsorption effect was explored. • The modification of citric acid can effectively avoid the agglomeration of adsorbent.