Engineers at the Korea Institute of Civil Engineering and Building Technology (KICT) have developed a desalination technique that makes seawater apt for consumption in just minutes.
The technology uses a nanofiber membrane distillation process that could desalinate water with 99.99% efficiency. The team believe that commercializing this technology could help meet the world’s drinking water needs in the future, since only 2.5% of the water on Earth is freshwater.
Reverse osmosis is the most common method currently used in desalination of seawater, used in around 20,000 facilities globally. Reverse osmosis has a high energy consumption and also leaves harmful byproducts which usually end back into seawater.
The engineers at KICT have developed co-axial electrospun nanofiber membranes fabricated by an electrospinning nano-technology. It can prevent challenges and wetting issues and also improve the long-term stability of the membrane distillation process.
The engineers used poly (vinylidene fluoride-co-hexafluoropropylene) as the core and silica aerogel mixed with a low concentration of the polymer as the casing to produce a composite membrane with a superhydrophobic surface. This allows them to produce a filter that had a higher surface roughness and lower thermal conductivity. During the tests, the team was able to maintain stable membrane distillation for 30 days. During those 30 days, the nanofiber membrane obtained by electrospinning maintained a percentage of 99.99% in the rejection of salt. That’s a far longer runtime than other electrospun nanofiber membranes in previous studies that operated for less than 50 hours with high water vapor flux.
“The co-axial electrospun nanofiber membrane has strong potential for the treatment of seawater solutions without suffering from wetting issues and maybe the appropriate membrane for pilot-scale and real-scale membrane distillation applications,” says Dr. Yunchul Woo, lead researcher on the study.