Highly-efficient removal of Rhodamine B using a flow-through electrocatalytic filtration system: Characteristics, efficiency and mechanism

The objective of this research is to develop an effective electrocatalytic filtration system using Ti/SnO 2 -Sb membrane anodes for eliminating Rhodamine B (RhB) from wasteater. Compared to Ti/SnO 2 -Sb plate anode, the prepared Ti/SnO 2 -Sb membrane anodes featured smaller particle size, bigger electrocatalytic active surface area, lower charge transfer resistance, and higher potential for oxygen evolution. The electrocatalytic filtration system obtained RhB removal of 90.29% with EE/O of 5.51 kWh m −3 after 90 min of electrolysis when initial pH value was 5, current density was 10 mA cm −2 , initial RhB concentration was 50 mg L −1 , and membrane flux was 2.17 m 3 (m 2 ·h) −1 , respectively. The flow-through electrocatalytic filtration system was found to be limited by kinetics under a high membrane flux and dominated by an indirect radical oxidation. Finally, the possible RhB degradation pathways were proposed based on the detected intermediates and density functional theory calculations.