Design strategy of self-assembled BC@MIL-100(Fe) composite membrane for the efficient removal of diclofenac sodium from water.

Pharmaceuticals and personal care products (PPCPs) as typical emerging pollutant have attracted extensive attention due to the risks to human health and environment. As a kind of harmful PPCPs, diclofenac sodium (DCF) has been frequently detected in water environment, which needs to be removed effectively. Herein, we successfully fabricated network structure composite membranes consisting of one-dimensional (1D) well-defined core-shell bacterial cellulose (BC)@MIL-100 (Fe) nanofibers by a simple but effective step-by-step strategy. The BC@MIL-100(Fe) composite membrane has three-dimensional network utilizing bacterial cellulose nanofiber as template, which was observed as the MIL-100(Fe) grew on the nanofiber uniformly and obvious core-shell structure. Impressively, the BC@MIL-100(Fe) not only possessed favorable architecture but also behaved good properties to adsorb DCF from water. As we expected, the as-obtained BC@MIL-100(Fe) composite membrane exhibited convenient recycling, high chemical stability, and short equilibrium time (30 min) with high adsorption capacity (296 mg g). Strikingly, in low DCF concentration solution, BC@MIL-100(Fe) composite showed high adsorption efficiency in periodic test, which can still reach 70% after five successive adsorptions without desorption. The results demonstrated that the adsorption mechanism may involve π-π interaction, H-bond interaction, and electrostatic interaction. This work proposes the new finding to understand the removing of DCF from water environment.