Facile design of green engineered cellulose/metal hybrid macrogels for efficient trace phosphate removal

Cellulose/metal hybrid macrogels were prepared by immobilizing uniformly dispersed thiolate-modified Fe2O3 nanoparticles into a cellulose matrix. The structure and properties of the hybrid macrogels were characterized using SEM, EDS, water contact angle, XRD, FTIR, XPS, and adsorption tests. The hybrid macrogels exhibited good stability, convenient operation, and high selectivity for trace phosphate removal, with a remaining phosphorus concentration of only 0.15 mg L-1 in 200 min (5 mg L-1 initial concentration). The influences of pH, ionic strength, and competitive anions were also investigated. The hybrid macrogels could be recovered by simple and rapid magnetic separation and regenerated in NaOH solution. During 5 cycles of the adsorption-elution-regeneration stability test, the hybrid macrogels still retained 80% adsorption capacity of trace phosphate. In this work, utilization of natural polymer was, combined with green and sustainable technology to develop economically sustainable, eco-friendly, and cost-effective cellulose/metal hybrid macrogels for the application of trace phosphate removal from water.