Electrochemical detoxification of tetrabromobisphenol A-contaminated water using Ti/SnO2-Sb/PbO2-Ce anodic membrane

Degradation of refractory organics has been limited by their low mass-transport rates in conventional flow-by operated electrochemical reactors. This study explores for the first time the development of porous titanium (Ti)-based metal oxide anodic membrane for efficient flow-through degradation of recalcitrant tetrabromobisphenol A (TBBPA). For this purpose, a duplexed Ti/SnO 2 -Sb/PbO 2 -Ce anodic membrane was successfully prepared by sol-gel and electrodeposition methods. Ti/SnO 2 -Sb/PbO 2 -Ce exhibited improved mechanical and electrochemical stability, larger electrochemical surface area, higher oxygen evolution potential and lower charge transfer resistance, as compared to its mono-layered rival (Ti/SnO 2 -Sb). The switching from flow-by to flow-through operation resulted in an increased mass transfer rate constant and narrowed diffusion layer thickness of Ti/SnO 2 -Sb/PbO 2 -Ce. In the flow-through mode, Ti/SnO 2 -Sb/PbO 2 -Ce enabled the complete TBBPA removal at a relatively low electric energy (0.11 kWh m −3 ). The TBBPA removal was ascribed to the direct anodic oxidation and indirect anodic oxidation incurred by absorbed HO , free HO and 1 O 2 . The intermediate products, which were arisen from the attack of TBBPA by these reactive species, were identified. We further estimated their acute toxicities and bioaccumulation factors. This research proposed a robust electrochemical filtration approach for detoxification of TBBPA-contaminated water.