A self-cleaning thermocatalytic membrane for bisphenol a abatement and fouling removal

Abstract

Thermocatalytic, ceramic microfiltration membranes for continuous micropollutants removal and simultaneous degradation of organic fouling were synthesized by integrating a Sr0.85Ce0.15FeO3 (SCF) perovskite in alumina membranes and tested for the bisphenol A (BPA) abatement under different experimental conditions. Scanning electron microscopy (SEM) and Energy Dispersive X-ray spectroscopy (EDX) characterization techniques were used to characterize the samples. The effect of water flux, BPA concentration and temperature on the BPA and fouling removal was investigated in detail. Up to 55 % of BPA was removed by filtration of a 9.6 mg L−1 BPA solution at 40 °C and a flux of 25 LMH. Degradation studies with BPA feed concentrations of 3.4, 5.5 and 9.6 mg L−1 showed higher degradation rate by the membrane with higher concentrations of BPA. Furthermore, the rate of BPA degradation increases with lower permeate flux, due to the longer retention time of pollutant in the membrane. Membranes were fouled with humic acid to study the thermocatalytic fouling removal. After fouling, membranes were rinsed to remove external, removable fouling, which was followed by 20–120 min of thermal treatment at 40 °C. This showed up to complete recovery of permeability by reduction of hydraulic resistance from the internal fouling in the membranes. No effect of heat treatment was observed for fouled non-functionalized membranes. Hence, the novel membrane studied in this article is a promising solution for simultaneous degradation of micropollutants and recovery of permeability during filtration, e.g. in wastewater treatment.