Green preparation of Fe₃O₄/HA/CS magnetic nanoparticles for oil–water separation

Abstract

BACKGROUNDDemulsification using chitosan (CS)‐coated magnetic nanomaterials has garnered significant attention. However, traditional methods of for synthesizing chitosan (CS)‐coated magnetic nanomaterials are often contaminated, laborious, and time‐consuming. Moreover, they showed poor demulsification efficiency due to the occupation of free amino groups in CS by crosslinking agents.RESULTSCS‐coated Fe3O4 magnetic nanoparticles (MNPs) were synthesized using humic acid (HA) as a bridge. The Fe3O4/HA/CS MNPs are as recyclable demulsifiers for hexadecane‐water microemulsions. We assessed the impact of MNP dosage, separation time, and pH on demulsification efficiency. Compared with Fe3O4/HA and Fe3O4/CS MNPs, the demulsification efficiency of the Fe3O4/HA/CS MNPs was superior. The pseudo‐second‐order kinetic model and the Sips isotherm best describe the demulsification process. Combining with the influence factors of demulsification efficiency, the demulsification mechanism involves electrostatic interactions between MNPs and oil microparticles. The maximum adsorption capacity for oil by the Fe3O4/HA/CS MNPs was 91.73 mg/g.CONCLUSIONThis research presents a new method for connecting CS to MNPs with a high surface positive charge. As synthesized, Fe3O4/HA/CS MNPs is expected to serve as highly efficient and recyclable demulsifiers for emulsified oil wastewater.This article is protected by copyright. All rights reserved.