Microwave-assisted preparation of ZnFe2O4@methyl cellulose as a new nano-biomagnetic photocatalyst for photodegradation of metronidazole

In the present study, ZnFe2O4@methyl cellulose (MC) nano-biomagnetic photocatalyst was rapidly prepared based on a microwave-assisted method. FTIR, FESEM, EDS, UV-DRS, XRD, and VSM were performed to characterize the structure of as-prepared ZnFe2O4@MC. The removal efficiency of Metronidazole (MNZ) degradation was 92.65 and 71.12 in synthetic and real samples under optimal conditions, respectively. The removal efficiency of TOC was also reported to be 77.87 under optimal conditions. The kinetic linear models showed that the photocatalytic degradation of MNZ follows either a pseudo-first-order kinetic or the Langmuir-Hinshelwood model. The correlation coefficients (R2) were 0.92, 0.97, 0.99, and 0.94, respectively at 5, 10, 20, and 30 mg/L. The equilibrium adsorption coefficient (KL � H) of the Langmuir-Hinshelwood model and the superficial reaction rate constant (Kc) were 0.633 Lmg�1 and 0.203 mg/L min�1, respectively. The participation of active species such as holes and hydroxyl and superoxide radicals was studied during MNZ photodegradation with organic and inorganic radical scavengers. Finally, the nano-biomagnetic catalyst could be reused for six further runs without remarkable changes in catalytic efficiencies. In this study, we present a new magnetic nanocomposite and a novel strategy for antibiotic removal from aqueous media. © 2020 Elsevier B.V