Organic sandwich-structured carbon fiber/SiO2/PES electrochemical membrane with significantly improved charge transfer efficiency and water permeability

Abstract

Electrochemical membrane separation has the potential for good degradation efficiency and mitigates membrane fouling. However, it is still a real challenge to further build stable organic substrate and improve its charge efficiency. In this study, an electric conductive and sandwich-structured carbon fiber/SiO2/polyether sulfone (CF/SiO2/PES) membrane showing good tetracycline (TC) removal at both acidic (pH = 3) and alkaline (pH = 9) conditions was fabricated by a facile phase conversion method. The CF/SiO2/PES membrane exhibited notably improved water permeability, augmented by 42 % higher with external voltage than that of the membrane without voltage assistance. Furthermore, the CF/SiO2/PES membrane performance in TC removal was systematically assessed under diverse conditions, encompassing TC concentration, pH values, and applied voltage. The membrane displayed a good removal efficiency of 93.6 % and 91.8 % for TC at acidic and alkaline conditions, respectively. Additionally, the degradation pathway of TC was proposed. Crucially, the CF/SiO2/PES membrane exhibited exceptional reusability and stability over eight consecutive runs. Mechanism study proved that the reactive species play a key role in the TC degradation during electro-filtration. The exceptional permeability, removal efficiency, and recyclability position the CF/SiO2/PES membrane as a promising solution for antibiotic wastewater treatment.