Gravity-driven Fe-doped CoTiO3/SiO2 fiber membrane with open catalytic network: Activation of peroxymonosulfate and efficient pollutants removal

Abstract

Constructing a robust catalytic membrane with simultaneous fast liquid transport and efficient organic pollutant degradation is appealing for efficient organic wastewater treatment. Herein, Fe-doped CoTiO3 grew uniformly on the SiO2 fiber membrane to form a catalytic membrane (FCTSM). Benefiting from the great water wettability, FCTSM facilitated fast water transport with low energy consumption and exhibited high physical separation performance (98.4% rejection of oil in the emulsion). The catalytic active sites were fully exposed on membrane surface, which could easily react with peroxymonosulfate and target pollutants. Under the gravity-driven permeation, FCTSM performed decent catalytic degradation property (e.g., 96.3% removal of nimesulide with the flux of 300 L/m2·h) in the presence of peroxymonosulfate. Electron paramagnetic resonance (EPR) spectra and quenching tests found that SO4•− and 1O2 were involved in pollutant degradation, and the possible degradation pathway of nimesulide was investigated. Besides, the toxicity analyses based on quantitative structure–activity relationship (QSAR) verified the reduced toxicity of degradation products. This work provides an insight into the design of multifunctional membranes and advances the potential applications of heterogeneous catalytic oxidation in environmental remediation.