PSS-Functionalized Fe3O4/ZIF-67 Nanocomposite: An Efficient Adsorbent for Rapid Removal of Microplastics From Wastewater

Microplastic pollution poses a significant threat to ecosystems and human health, necessitating efficient removal methods. In this study, a magnetic nanocomposite, Fe 3 O 4 /PSS/ZIF-67, was synthesized via a solvothermal method, utilizing poly(sodium p-styrenesulfonate) (PSS) to functionalize Fe 3 O 4 nanoparticles for the in situ growth of ZIF-67. Under ultrasound-assisted conditions, the adsorbent exhibited exceptional performance for polystyrene (PS) microplastics, achieving equilibrium within 15 min with a maximum adsorption capacity of 2816 mg/g. The adsorption process followed pseudo-first-order kinetics and the Langmuir isotherm model. Mechanistic analyses revealed that the removal was driven by synergistic effects of van der Waals forces, electrostatic interactions, hydrogen bonding, and π–π interactions. Furthermore, the Fe 3 O 4 /PSS/ZIF-67 demonstrated broad-spectrum removal capabilities for various microplastics (PP, PE, PET, PMMA, PVC, PA), organic dyes (AB 93, MB, MO, CR, CV, MG, R6G), heavy metal ions (Fe 3+ , Ni 2+ , Cu 2+ , Zn 2+ ), and antibiotics (TC, CIP), demonstrating its potential for wastewater treatment.