Electrocoagulation-Based Removal of Polypropylene Microplastics from Water: Process Optimization and Characterization of Fe3O4-C Flocs

Abstract

Microplastics (MPs) have emerged as a serious threat to humans and aquatic life owing to its persistence and widespread contamination. Among several treatment technologies, electrocoagulation (EC) has garnered significant interest as a reliable, effective and eco friendly technique for the removal of MPs from water. This study investigates the removal of polypropylene (PP) MPs using EC process with Fe electrodes and examines the valorization of generated EC sludge into functional materials (Fe3O4/C) with potential as anode material in Li ion batteries. The process optimization was done through Central Composite Design under Response Surface Methodology (RSM), evaluating current density, electrolysis time, pH and NaCl concentration as operating variables. An ANN model was developed to predict the process performance and compare its predictive capability with RSM. The EC sludge was carbonized under air and inert conditions and the resultant composites were characterized by FTIR, XRD, FE-SEM, EDS, XPS, DLS and Raman, which proved that carbonized Fe3O4/PP flocs under Ar retained Fe3O4 with improved structural characteristics. Overall, this study demonstrates EC removing MPs effectively along with generated sludge being converted into value-added materials, thereby, supporting sustainable wastewater treatment and waste to value approach.