Mass transfer and interfacial reaction mechanisms in a novel electro-catalytic membrane contactor for wastewater treatment by O3

•A novel membrane contactor coupling with electro-peroxone was constructed.•The removal rate of nitrobenzene was significantly improved in ECMCO process.•The mass transfer of O2 in ECMCO was promoted relative to conventional process.•ECMCO has great potential on the production of OH.•Porosity and thickness of the membrane critically affect the efficiency of ECMCO.