Electrospun ZIF-67/PVDF composite membranes for efficient ciprofloxacin removal from wastewater

Cobalt 2-methylimidazole (ZIF-67) has been broadly explored for its applications in the treatment of antibiotics in wastewater. However, ZIF-67 in powder form is difficult to recover. In the study, ZIF-67 and Polyvinylidene Fluoride (PVDF) were blended via electrospinning to prepare ZIF-67/PVDF membrane for adsorption of ciprofloxacin (CIP). The ZIF-67/PVDF membrane demonstrated outstanding adsorption efficiency for CIP, with a maximum adsorption capability of 4087.5 microg cm^-2. The adsorption performance of ZIF-67/PVDF remains stable across a wide pH range and is unaffected by ionic interference. The ZIF-67/PVDF adsorbent follows pseudo-second-order kinetics and the Langmuir model. Furthermore, thermodynamic research indicates the adsorption of CIP is a spontaneous and exothermic process. It is proposed that the adsorption mechanism of CIP onto ZIF-67/PVDF involves electrostatic interactions, hydrogen bonding, π-π interactions, coordination bonding, and hydrophobic interactions.