High adsorption for ofloxacin and reusability by the use of ZIF-8 for wastewater treatment

In this study, by the application of the strong interaction between a metal-organic framework material and ofloxacin, ZIF-8 was proposed as an absorbent to remove ofloxacin from wastewater. The results demonstrated that ZIF-8 could remove 96.3 +/- 1.1% of ofloxacin from the ofloxacin solution of 100 mg/L, and the maximum equilibrium adsorption capacity reached 194.1 +/- 0.4 mg/g, which is superior to that of an adsorbent based on physical adsorption. The high specific surface area and strong interaction between ofloxacin and ZIF-8, including strong hydrogen bonding, complexation of unsaturated metals, and electrostatic interactions, contributed to the adsorption process. Moreover, the adsorption efficiency reached 80.2% after four adsorption cycles. The pseudo -second-order kinetics and Langmuir adsorption model can describe the adsorption of ofloxacin by ZIF-8. Therefore, ZIF-8 is a promising material for the treatment of wastewater containing ofloxacin.