Construction of magnetic sulfonic-functionalized hypercrosslinked polymers for efficient adsorption of azole fungicides from water

Azole fungicides are frequently used in agricultural practice, and can leach into surface water through farmland, leading to negative impacts to environment and human health. Herein, a novel magnetic sulfonic-functionalized hypercrosslinked polymer (MHCP-SO 3 H) was fabricated by crosslinking of the phenyl-functionalized magnetic nanoparticles via Friedel-Crafts alkylation strategy with a simple post-modification process. Significantly, Friedel-Crafts reaction is moderate and no extreme operating conditions are required. It is the first attempt that hypercrosslinked polymers were employed to achieve efficient adsorption of azole fungicides from water. Benefiting from the hypercrosslinked framework, high specific surface area, stable magnetic structure and abundant adsorption active sites, MHCP-SO 3 H exhibited fast separation (20 s), short adsorption equilibrium time (30 min), extraordinary reusability and outstanding adsorption capacity for azole fungicides, with the maximum adsorption capacities of 65.47 mg/g for tebuconazole and 63.28 mg/g for epoxiconazole, respectively. Furthermore, the adsorption process for azole fungicides on MHCP-SO 3 H conformed to pseudo-second-order kinetic model and Freundlich isotherm model. In particular, the interactions affecting the adsorption were discussed combining adsorption experiments with molecular docking study. pi- pi stacking, hydrogen bond, hydrophobic interaction and pore-filling effect were confirmed to be the main adsorption mechanisms. Our findings not only provide the feasible way as a facile, environmentally friendly and cheap strategy for synthesizing magnetic adsorbents, but also identify it as a promising approach in the field of removing environmental pollutants.