The effect of tannic acid –based coating on performance of Ro membrane for metronidazole removal from aqueous solution

The current study focused on the surface modification of commercial polyamide thin film composite (TFC) membrane via a green method. For this purpose, the tannic acid–Cu(II) complex was applied as an antifouling and antioxidant coating on the surface of the TFC membrane. The structure and surface properties of the modified membrane had been characterized by Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-Ray (EDX), Atomic Force Microscopy (AFM), and Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy. The obtained results confirmed the successful formation of complex coating and its impact on the structure of the modified membrane. The separation performance of the modified membrane was determined via metronidazole (MNZ) removal from an aqueous solution. Regarding the results, surface modification of TFC membrane enhanced rejection from 87.5 to 94.19%, while permeability decreases from 1.173 to 1.034 LMHbar. The antifouling property of the modified membrane was also investigated via BSA solution filtration. The tannic acid-Cu(II) coated TFC membrane exhibited excellent enhancement for antifouling parameters when compared with the unmodified TFC membrane.