Effective Removal of Antibacterial Drugs from Aqueous Solutions Using Porous Metal–Organic Frameworks

Effective removal of antibacterial drugs attracts more and more attentions with the rapid development of pharmacy industry, while still facing large challenge in removal efficiency to date. Herein, porous MIL-101 and SO3H-MIL-101 were systematically studied for their adsorption performances toward two common antibacterial drugs, gemifioxacin mesylate (GEM) and moxifloxacin hydrochloride (MOX). It was found that SO3H-MIL-101 can exhibit high adsorption capacities of 528 mg g−1 and 447 mg g−1 for GEM and MOX at natural pH respectively, superior to those of MIL-101 and other common MOFs-based adsorbents. The adsorption kinetics study indicates that the adsorption onto SO3H-MIL-101 follows pseudo-second-order model. Furthermore, it was found that the adsorption capacity of SO3H-MIL-101 increased at pH range of 2.0–7.0 and decreased at pH range of 7.0–10.0. Further study indicates that the two MOFs can be easily regenerated even after four cycles. Mechanism analysis demonstrates that surface potentials of the MOFs play critical effects on the adsorption processes for the amphipathic drugs and the introduction of –SO3H groups can effectively regulate the adsorption performance of the MOF. This work may provide an effective approach to modify the adsorption behaviour of the MOFs.