Rapid and effective antibiotics elimination from water by Fe-BTB MOF: An insight into adsorption mechanism

Tetracycline (TC) and sulfamethoxazole (SMZ) are common antibiotics utilized in human and veterinary medicines to overcome bacterial infections. However, due to their poor metabolism, they can easily be excreted into wastewater or sewage, leading to bioaccumulation and posing a risk to the local environment. This research studied the removal of SMZ and TC using a novel Fe-BTB MOF. The results showed that the Fe-BTB MOF achieved excellent adsorption capacities of 649 and 276 mg g−1 for SMZ and TC, respectively, within 1 h. The kinetics and equilibrium adsorption data correlated well with the pseudo-second-order and Sips models, respectively, suggesting favourable chemical adsorption for SMZ and TC over the MOF. Adsorption experiments, spectroscopic findings, and theoretical calculations suggest that π-π stacking, electrostatic, and hydrogen bond interactions played the main role in the adsorption mechanism. Fe-BTB regeneration was satisfactory for its use in treating antibiotic-contaminated wastewater, allowing its reuse for at least four cycles. Furthermore, water samples from different sources (tap, streams, sea, lake) were also used to confirm the excellent adsorptive performance of this Fe-BTB MOF in practical application.