The Enhancement Effect and Mechanism of Natural Clay on the Removal of Polyethylene Microplastics by Electrocoagulation

ABSTRACT This study introduces a novel strategy to enhance the removal of polyethylene microplastics (PE‐MPs) from wastewater by integrating natural clay minerals into the electrocoagulation (EC) process. The innovation lies in leveraging clay as a synergistic agent to address the inherent challenge of poor floc sedimentation. Experimental results demonstrated that all tested clays significantly improved PE‐MP removal, with montmorillonite (0.5 g/L) exhibiting the highest performance. By reducing the absolute zeta potential from −22.67 to +9.85 mV within 3 min of addition, montmorillonite promoted charge neutralization and facilitated the formation of larger, denser flocs via a “net capture and sweeping” mechanism. Under optimal conditions, this synergistic process achieved a high PE‐MP removal efficiency of 84.4%. Kinetic and isotherm analysis revealed that the adsorption process followed pseudo‐first‐order kinetics and the Langmuir monolayer adsorption model. This study confirms that the integration of low‐cost natural clay with EC is a highly efficient and promising technology for microplastic remediation.