Electrochemical removal of polystyrene nanoplastics in a filter-press reactor using modified Ti-felt anodes: Comparison of flow-through and flow-by configurations

Ti-felt anodes, with high surface area, have been used as supports of Pt and SnO 2 -Sb-Pt electrocatalysts. Anodes have been applied in a filter-press electrochemical reactor for the electrooxidation of polystyrene nanoplastics (NPs) (100 mg·L −1 ). Two types of configurations have been used. In the first, the solution with NPs flows through the anode, taking advantage of its porosity (acting as a sort of membrane) to enhance the contact of NPs with the anode and the oxidative species generated. In the second configuration, the solution of NPs flows parallel to the anode, and the NPs flow parallel to it. Comparing both configurations at 25 mA·cm −2 , for the Ti Pt anode, the flow-through configuration decreases energy consumption by ~7-foldand treatment time by ~15-fold when compared to the flow-by configuration. For Ti-SnO 2 -Sb-Pt anode, ratios of ~6.5-fold and ~ 13-fold were obtained, respectively. Moreover, the effect of the current density (50, 25, 12.5, and 5 mA·cm −2 ) was studied. For the Ti Pt electrode, a treatment time of only 40 min was achieved at a current density of 25 mA·cm −2 with the F-T configuration, with a faradaic efficiency of 62.09%, and electrochemical energy per order (EEO) of21.91 kW·h·m −3 ·order −1 . In the case of the F B configuration at 25 mA·cm −2 the treatment time increases until 600 min, with a faradaic efficiency of 8.27% and EEO of 156.57 kW·h·m −3 ·order −1 . • Ti-felts are used as support for Pt and SnO 2 -Sb-Pt coatings to obtain anodes. • Anodes are used as reactive membrane electrodes in a filter-press reactor. • 100 nm polystyrene nanoplastics electrooxidation was performed (100 mg·L −1 ). • Flow-through (F-T) and flow-by (F B) configurations were tested. • Flow-through configurations decreased treatment time, and energy consumption.