The efficient removal of diclofenac and indomethacin with novel polyaniline-modified microcrystalline cellulose/covalent organic framework nanocomposites

Background: To address the problem of pharmaceuticals and personal care products (PPCPs) contamination, a novel polyaniline-modified microcrystalline cellulose/covalent organic framework nanocomposite (MCC/COF/ PANI) was synthesized for the removal of indomethacin (IDM) and diclofenac (DCF).Methods: MCC/COF/PANI was synthesized by solvothermal and in-situ polymerization methods.Significant findings: The MCC/COF/PANI obtained fast and good adsorbing performance for pollutants within 60 min. The maximum adsorption capacities of MCC/COF/PANI on IDM and DCF were 149.1 and 112.5 mg/g. The adsorption kinetics and isotherm of MCC/COF/PANI on IDM/DCF were fitted to the pseudo-second-order, Langmuir/Freundlich mode. Moreover, XPS, BET and FT-IR proved that the adsorption mechanism of MCC/ COF/PANI on pollutants mainly involved in the pore filling, pi-pi interaction, electrostatic interaction and hydrogen bonding. In addition, the MCC/COF/PANI showed good stability and reusability with high removal rates of IDM (76.8%) and DCF (76.6%) even after five adsorption-desorption cycles. Generally, the prepared MCC/COF/PANI nanocomposites had application in the removal of PPCPs from the water environment.