Water Desalination via Pressure-Driven Distillation with Chlorine-Resistant and Large-Area Polymeric Membranes

Pressure-driven distillation is a separation process in which hydraulic pressure is used to drive water vapor transport across an air-trapping porous hydrophobic membrane. Current development of pressure-driven distillation is limited by a lack of robust, large-area membranes. Here, we report desalination using pressure-driven vapor transport through scalable polymeric polytetrafluorethylene membranes. The membranes showed pressure-driven water flow with near-complete rejection of sodium chloride (greater than 99%) under hydraulic pressures of up to 10.3 bar. Membrane structure, surface chemistry, and desalination performance were found to be unaffected by doses of sodium hypochlorite up to 3000 ppm h. Flux decline due to biofouling from Pseudomonas aeruginosa bacterium was effectively mitigated using chlorine. Membranes also exhibited high temperature resilience with operation up to 60 °C. Overall, this work demonstrates the use of large-area polymeric materials in pressure-driven distillation and highlights key advantages in chlorine and heat tolerance.