Water desalination is extremely important due to the rising imbalance between freshwater usage and availability. To extract fresh water from the oceans, distillation and filtration approaches are used, e.g., membrane distillation (MD) and reverse/forward osmosis (RO and FO). However, current methods are energy-intensive and high throughput is often difficult to achieve.
Zhiping Lai, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia, Ping Sheng, Hong Kong University of Science and Technology, China, and colleagues have developed a nanoporous carbon composite membrane that can achieve 100 % desalination and a high throughput. The membrane is composed of a porous ceramic support made of yttrium-stabilized zirconia and a carbon fiber layer with gaps through which water can be transported.
The researchers demonstrated that the rapid transport of water vapor through the nano-sized carbon pores is facilitated by the exceptionally smooth carbon surface, which lowers the transport resistance, accompanied by Knudsen diffusion paths at the nanoscale. The membrane was used in MD, RO, and FO processes and showed freshwater fluxes that were up to 20 times higher than current technologies.
- High-flux water desalination with interfacial salt sieving effect in nanoporous carbon composite membranes,
Wei Chen, Shuyu Chen, Tengfei Liang, Qiang Zhang, Zhongli Fan, Hang Yin, Kuo-Wei Huang, Xixiang Zhang, Zhiping Lai, Ping Sheng,
Nat. Nanotechnol. 2018.