RETRACTION: Visible-light-drivenmitigation of antibiotic oxytetracycline and disinfection of Escherichia coli using magnetic recyclable Ag-modified zinc ferrite/diatomite ternary hybridmaterial (Retraction of Vol 94, Pg 2537, 2019)

BACKGROUND The pharmaceutical residues in water are considered globally to be typical hazardous pollutants. Many technologies have been reported to eliminate these residues, such as photocatalysis, which has usually been applied in a suspension system with powdery photocatalyst. The disadvantage of this system, hindering its practical application, is its low recyclability. Ferrite-based photocatalysts have been synthesized to resolve this problem. In this work, silver (Ag)-modified zinc ferrite (ZnFe2O4) nanoparticles were immobilized onto porous mineral diatomite. The physicochemical properties of this composite were studied systematically, and its photocatalytic efficiency was investigated via the degradation of antibiotic oxytetracycline (OTC) and disinfection of bacteria Escherichia coli under visible light. RESULTS The degradation rate increased after the catalyst was immobilized onto diatomite, due to the adsorption and degradation synergistic effect. The Ag cluster improved the visible-light-driven photoactivity of ZnFe2O4, and its optimal percentage was determined. The best catalyst dosage during the degradation process also was obtained. The optimal catalyst exhibited its removal rate of OTC (10 mg L-1 aqueous solution) as 90.5% in 2.5 h, and disinfection rate of E. coli as 87.2% in 2 h, under visible light irradiation. Moreover, the photocatalysis mechanism was illustrated. CONCLUSION This composite could be recovered simply from the water body via an external magnet, and indicated no obvious decrease of photoactivity after being recycled five times for photodegradation or photodisinfection tests. This nanocomposite showed good potential for application in wastewater remediation process, thanks to its high photocatalytic efficiency under visible light, as well as its good reusability and stability. (c) 2019 Society of Chemical Industry