作者： Rongzhen Chen，Xialu Liao，Qingchun Ge

College of Environment and Resources, Fuzhou University, No.2 Xueyuan Road, Fujian 350116, China

摘要：The unavailability of a suitable draw solute constrains the advancement of forward osmosis (FO) technology. Here from a custom-built ionic liquid betainium bis(trifluoromethylsulfonyl)imide ([Hbet][Tf₂N]), a multinuclear zinc complex of [Zn₄(bet)₁₀(H₂O)₂][Tf₂N]₈ (Zn-Bet-Tf₂N) has been synthesized via a one-pot complexation reaction for electroplating wastewater treatment via FO processes. Possessing a large number of hydrophilic groups and an expanded structure, Zn-Bet-Tf₂N generates a sufficient osmotic pressure to drive the FO process and minimizes reverse solute diffusion. Zn-Bet-Tf₂N produces a water flux of 15.0 LMH even at a dilute concentration (0.2 mol/L) with negligible solute leakage during the FO process. The water permeation rates induced by Zn-Bet-Tf₂N increase by up to 50 % compared to those of the conventional NaCl, MgCl₂ and NH₄HCO₃ draw solutes in zinc-containing wastewater reclamation. Zn-Bet-Tf₂N is readily separated from water after FO through solvent extraction. With no energy input or by-products, the recycling of Zn-Bet-Tf₂N is more practical than that of other draw solutes ever reported. Reproducible results are obtained when the recycled Zn-Bet-Tf₂N is reused to FO processes. These findings suggest that the Zn-Bet-Tf₂N facilitated FO system can achieve high water recovery efficiency, high selectivity and sustainability in zinc-containing wastewater treatment.