Designing anti-fouling PVDF membranes by synergizing Cu2+ and sodium lignosulphonate additives

Membrane separation technology with high separation efficiency and low energy consumption are one of the keys to tackle the water-energy crisis. However, membrane fouling can reduce membrane life and performance, limiting its application. In this work, hydrophilic modifier sodium lignosulphonate (SLS) and antibacterial agent CuCl 2 were adopted as additives to modify PVDF membranes. The addition of SLS can optimize the structure of PVDF membranes and increase hydrophilicity, enhancing separation and anti-fouling performance. Moreover, the SLS can fix Cu 2+ effectively onto the membrane for improved antibacterial performance, as the leakage of Cu 2+ is reduced greatly, compared to Cu-PVDF membranes without SLS. The simulation based on density functional theory proved that the binding energy of SLS and Cu 2+ is 2.7 times of that of PVDF and Cu 2+ . Finally, the prepared anti-fouling Cu-SLS/PVDF membrane was applied in the separation of simulated Escherichia coli fermentation broth, exhibiting long-term antibacterial and anti-fouling property. This work provides a new idea for the preparation of long-term anti-fouling and antibacterial membrane, and has good potential in the recovery of fermentation broth.