Fluorinated/sulfonated dual-functional three-component covalent organic polymer for adsorption of fluoroquinolones: Preparation, adsorption performance and mechanism

Due to the low performance of traditional water treatment methods, the effective removal of fluoroquinolone (FQs) is of great significance for environmental protection. Based on the structural characteristics of FQs, a fluorinated/sulfonated dual-functional three-component covalent organic polymer [COP, named TpBD-CF3(0.25)SO3H0.75) ] was deliberately designed via Schiff reaction, which attempted to realize high removal performance of FQs from different environmental water samples. The results of adsorption performance showed that TpBD- CF3(0.25)SO3H(0.75) could realize high removal performance of FQs via synergistic effect of electrostatic, hydrogen bonding, F-F affinity, pi-pi and hydrophobic interactions. The adsorbent exhibited fast adsorption rate (can reach adsorption equilibrium in 10 min) and high removal efficiency ( > 90 %) for the four concerned FQs, and their adsorption capacity ranged from 65 to 81 mg/g. The results of adsorption kinetics, thermodynamics and isotherm consistently showed that the adsorption of FQs was chemical adsorption. The removal efficiencies of FQs in different water samples were all above 90 % after treated by the adsorbent. The adsorbent has good reusability, and the removal efficiency decreased only by 1 %-4 % after four adsorption - desorption cycles. In addition, the adsorbent has the potential to be used for enrichment of trace FQs in aqueous samples.