Efficient degradation of antibiotics by photo-Fenton reactive ceramic membrane with high flux by a facile spraying method under visible LED light

The traditional treatment of antibiotics confronts high energy consumption but low removal efficiency. In this study, a photo-Fenton ceramic membrane (PF-CM) was prepared by an innovative and facile approach of spray printing method with nano hematite (α-Fe2O3) for the removal of tetracycline hydrochloride (TC) as a model antibiotic. The SEM, TEM, XPS, and UV–Vis DRS were used to characterize the PF catalyst of α-Fe2O3. The as-prepared α-Fe2O3 was loaded to a flat ceramic membrane (CM) by a spray printing and low-temperature sintering method to form a photo-Fenton reactive membrane (α-Fe2O3-CM). A new α-Fe2O3-CM fixed bed water treatment system with visible LED light was fabricated for the removal of TC by comprehensive consideration of degradation rate and permeates flux. The reusability and stability of the α-Fe2O3-CM were also investigated. To reveal the reactive radicals involved in the PF-CM process for a deeper insight into the degradation mechanisms, quenching experiments and EPR analysis were performed. The SEM/EDS images indicated that the α-Fe2O3 was loaded tightly onto the α-Fe2O3-CM, and pure water permeates flux of the α-Fe2O3-CM could reach as high as 55.8 kg/(m2·h·kPa). The α-Fe2O3-CM fixed-bed treatment system is suited for TC treatment, and the removal efficiency could reach 82% even when the TC concentration is as low as 20 mg/L. Moreover, α-Fe2O3-CM could retain long-term stability and exhibit a self-cleaning function in antibiotic wastewater treatment for five cycles, which was further confirmed by SEM/EDS images and iron dissolution experiments. The quenching experiments and EPR analysis revealed that reactive radicals involved in the PF-CM process were h+, ·O2−, and, ·OH responsible for TC degradation. This research also provides a utilization proposal for scale-up α-Fe2O3-CM for water and wastewater treatment.