Covalent organic polymer/chitosan multifunctional granular aerogels for diclofenac sodium removal from water

[Display omitted] •Dual-functional (–COOH, –NH2) covalent organic polymer (COP) was synthesized.•Granular aerogels (CCN-AG-x, x = COP loading) were prepared from COP and chitosan.•CCN-AG-80 exhibited the best combination of surface area and mechanical strength.•CCN-AG-80 had low density, easy processability, & good solvent stability.•CCN-AG-80 featured high DFS adsorption capacity, fast kinetics, & recyclability. The adsorptive removal of pharmaceutical contaminants, such as diclofenac sodium (DFS), from water is of high environmental importance because of their adverse biological effects.Covalent organic polymers (COPs) show good DFS removal performance but are poorly suited for industrial applications because of their powder form. Herein, we synthesized an amine- and carboxyl group-rich aromatic COP (CCP-NH2) with a large surface area (1227 m2/g) and used it to prepare a series of granular CCP-NH2/chitosan aerogels (CCN-AG-x, where x = 0–90 wt% is the loading of CCP-NH2). The best-performing sample, CCN-AG-80, exhibited a high surface area and mechanical strength, low density, excellent stability in various solvents, and facile processability into different shapes. Moreover, CCN-AG-80 exhibited a high DFS adsorption capacity (501 mg/g), fast adsorption kinetics (