Effects of operating conditions on removal of microplastics (PET, PP, PS) from wastewater by electrocoagulation systems and kinetics of chromium removal in the presence of microplastics

The effects of operating parameters on microplastic (MP) removal and chromium removal kinetics in the presence of MPs were examined utilizing an Al/Fe-graphene-Electrocoagulation (EC) system. The best removal of all microplastics was achieved at pH 5.5, 0.1 M NaCl and 10 V for the Al/graphene electrode setting. In contrast, for the Fe/graphene electrode, the best removal was achieved at pH 7, 0.1 M NaCl and 14 V. Al-graphene electrode exhibited higher microplastic removal efficiency, achieving up to 96 % removal, compared to Fe-graphene electrode arrangement. Fe-graphene electrode demonstrated better chromium removal efficiency, achieving over 99 % removal. The kinetics of hexavalent chromium removal were best described by the second -order model for both Al/Fe-graphene electrode systems. From sludge characterization, the Fe anode shows a greater role in removing chromium than the Al electrode. This study highlights the potential of EC as an effective and versatile technology for the removal of microplastics and chromium from industrial wastewater under various operating conditions.