La(OH)3 loaded magnetic nanocomposites derived from sugarcane bagasse cellulose for phosphate adsorption: Characterization, performance and mechanism

Abstract

The magnetic nanomaterials Mg-Al-La LDH/Fe3O4/C were prepared using Fe3O4/C as a precursor by hydrothermal and co-precipitation method, and served as adsorbents for the efficient uptake of phosphorus from aqueous solutions. The effects of adsorbent dosage, pH and co-existing ions on the adsorption of phosphate were studied. The adsorption performance of the material was described by the adsorption kinetic model, isothermal model and thermodynamic model. When the pH value of the solution is in 4–7, it shows a high phosphate removal rate (>98.7%). The maximum phosphate removal rate (99.43%) was obtained at pH=6. The phosphate adsorption process by Mg-Al-La LDH/Fe3O4/C was best described by the Langmuir isotherm model and pseudo-second-order reaction kinetics. The maximum adsorption capacity for phosphate was evaluated as 106.21 mg/g. The optimization of phosphate adsorption was carried out by response surface design. The adsorption mechanism of Mg-Al-La LDH/Fe3O4/C for phosphate could be explained by ion exchange, electrostatic attraction and ligand exchange. Experiments have proved that Mg-Al-La LDH/Fe3O4/C nanocomposite can be used as a potential material for adsorbing phosphate in polluted water.