Exploring the state-of-the-art in metal-organic Frameworks for antibiotic adsorption: A review of performance, mechanisms, and regeneration

The application of metal-organic frameworks (MOFs) towards the adsorption of antibiotics is a new and emerging area of study. The rise in use or misuse of antibiotic products has exacerbated their ongoing presence and persistence in the natural environment. Even at low concentrations, antibiotic residues exert pressure on bacterial populations, eventually leading to the emergence of resistant bacteria. Metal-organic frameworks, known for their high porosity, vast specific surface area, and ease of modification, have emerged to be a promising and sustainable antibiotic adsorbent. In an effort to advance the development of this adsorbent, this study provides a state-of-the-art review of recent research published from 2020 to the present, specifically examining the use of MOFs for removing antibiotics from aqueous solutions. Multiple MOF adsorbents were analyzed, with approximately 59% demonstrating significant adsorption capacity within the pH range of 6.0-8.0. In 75% of the instances, the adsorption system reached equilibrium in under 2 hr. Adsorption capacities compared well to other published works in the literature and exceeded conventional adsorbents in many instances. Notable cases of MOF performance were MIL-53(Al) adsorption of amoxicillin (AMX) and SA-g-P3AP@MOF(Fe)/Ag adsorption of neomycin where adsorption capacities of 758.5 and 625.0 mg/g were attained, respectively. The reusability of MOFs was extensively reported at the laboratory batch scale. Analysis of the reported studies revealed the most effective eluents were acetone, ethanol, and methanol, with mostly 3-5 cycles attainable without appreciable loss in efficiency. The recent literature confirmed that MOFs are highly efficient in the adsorption of antibiotics; however, there are some areas that warrant further development. It is intended that this work will bring recent trends to the forefront, identify knowledge gaps, and help guide future research proposals.