Efficient magnetic capture of PE microplastic from water by PEG modified FeO nanoparticles: Performance, kinetics, isotherms and influence factors.

Due to their resistance to degradation, wide distribution, easy diffusion and potential uptake by organisms, microplastics (MPs) pollution has become a major environmental concern. In this study, PEG-modified FeO magnetic nanoparticles demonstrated superior adsorption efficiency against polyethylene (PE) microspheres compared to other adsorbents (bare FeO, PEI/FeO and CA/FeO). The maximum adsorption capacity of PE was found to be 2203 mg/g by adsorption isotherm analysis. PEG/FeO maintained a high adsorption capacity even at low temperature (5°C, 2163 mg/g), while neutral pH was favorable for MP adsorption. The presence of anions (Cl, SO, HCO, NO) and of humic acids inhibited the adsorption of MPs. It is proposed that the adsorption process was mainly driven by intermolecular hydrogen bonding. Overall, the study demonstrated that PEG/FeO can potentially be used as an efficient control against MPs, thus improving the quality of the aquatic environment and of our water resources.