Investigation of the dye and antibiotic removal efficiency of some metal-organic framework (MOF) compounds

In this study, MIL-53(Al), Co/UiO-66 and ZIF-67 metal-organic frameworks (MOFs) were synthesized, and their effectiveness in the removal of indigo carmine and ciprofloxacin was investigated. The adsorption efficiency of each MOF for indigo carmine and ciprofloxacin was studied under three different synthesis parameters, and the optimum conditions were determined. XRD and FTIR analyses confirmed the successful synthesis of each MOF, while N2 adsorption-desorption measurements showed that the BET surface areas varied depending on the synthesis conditions. The morphological properties of MIL-53(Al), Co/UiO-66 and ZIF-67 were investigated by FESEM analysis, and the distinct structural features of each MOF were observed. In adsorption studies, the optimum conditions for indigo carmine removal were determined. Kinetic model studies revealed that all MOFs fit the pseudo-second order kinetic model for indigo carmine adsorption and isotherm model studies showed that the Langmuir isotherm model provided the best fit for all MOFs. The maximum adsorption capacities for indigo carmine were calculated as 156 mg g-1, 357.1 mg g-1 and 370 mg g-1 for MIL-53(Al), Co/UiO-66 and ZIF-67, respectively. In the removal of ciprofloxacin, the kinetic model studies of MIL-53(Al), Co/UiO-66 and ZIF-67 were found to better fit the pseudo-second order kinetic model. Isotherm model studies for ciprofloxacin showed that MIL-53(Al) and ZIF-67 fit the Langmuir model and Co/UiO-66 fit the Freundlich model. The maximum adsorption capacities for ciprofloxacin were calculated as 188.7 mg g-1, 45.17 mg g-1 and 322.6 mg g-1 for MIL-53(Al), Co/UiO-66 and ZIF-67, respectively. The effect of NaCl salt concentrations on each adsorption process was investigated. Reusability studies demonstrated that MIL-53(Al), Co/UiO-66, and ZIF-67 exhibited sustainable adsorption performance for both indigo carmine and ciprofloxacin. All three MOFs showed high adsorption efficiencies, making them strong candidates for the removal of indigo carmine dye and ciprofloxacin antibiotic pollutants. Additionally, they are water-resistant, making them advantages for wastewater treatment applications.