Facile synthesis of low-cost magnetic biosorbent from peach gum polysaccharide for selective and efficient removal of cationic dyes

Magnetic biosorbents derived from renewable resource are emerging as a new class of adsorbing material for environmental cleanup because of their eco-friendly characteristic, easy availability and low cost. Herein, a novel magnetic peach gum bead (MPGB) biosorbent was successfully fabricated by a simple one-step reaction based on the simultaneous formation of magnetic nanoparticles and cross-linking of natural peach gum polysaccharide. Benefiting from the combined merits of peach gum and magnetic nanoparticles, the MPGB not only showed excellent adsorption performance for cationic dyes but also exhibited convenient magnetic separation capability. The influences of pH, ionic strength, initial dye concentration, contact time and temperature on the adsorption property of MPGB biosorbent were investigated by choosing methylene blue (MB) as a representative cationic dye. The Langmuir isotherm fitted the adsorption isotherm well with maximum adsorption capacity of 231.5 mg g−1. Kinetic data showed good correlation with pseudo-second-order model. Thermodynamic investigation revealed that the adsorption process was spontaneous and endothermic. Moreover, the MPGB exhibits nice reusability. Considering the facile fabrication process and excellent adsorption performance, the MPGBs hold great promise for using as biosorbent for environmental cleanup.