Ionic and Non-ionic Organic Porous Adsorbents for the Removal of Chloramphenicol and Ciprofloxacin from Water

Abstract

Nanoporous organic materials with varying pore sizes were utilized to remove antibiotics from surface and groundwater. These adsorbents belong to the group of Covalent Organic Frameworks (COFs), known for their high stability, porosity, and large surface area. Given their characteristics, which are well-suited for adsorption applications, these materials demonstrated relatively high capture capacities for emerging organic pollutants such as chloramphenicol (182 mg/g for RIO-55) and ciprofloxacin (79 mg/g for RIO-55) compared to other organic porous adsorbents. To conduct a comparative study on adsorption efficiency, both ionic and non-ionic materials were selected. Some ionic materials exhibited greater affinity for pharmaceutical compounds due to different adsorption mechanisms. Additionally, tests using a real water sample from the Tagus River confirmed the materials’ removal efficiency. A correlation was observed between the maximum adsorption capacity and the pore width of the COFs, suggesting that better fitting of these adsorbates into mesopores enhances adsorption performance.