A team led by a University of Limerick researcher has made a major breakthrough in water filtration that lets it use 1,000 times less energy than conventional methods.
With climate change expected to increase areas of land unsuitable for human habitation – either through coastal flooding or drought – the need to discover cheap and easy ways to filter water has never been greater.
A new process for water filtration using carbon dioxide, consumes one thousand times less energy than conventional methods.
The scientific research was published by a group of researchers, including the University of Limerick’s Dr Orest Shardt and Dr Sangwoo Shin from the University of Hawaii, last week.
Currently, water filtration technologies, such as microfiltration or ultrafiltration, use porous membranes to remove suspended particles and solutes.
These processes trap and remove suspended particles, such as fine silt, by forcing the suspension through a porous material with gaps that are smaller than the particles.
However, energy must be wasted to overcome the friction of pushing the water through these small passages, making it expensive for industries to pump and maintain these filtration systems.
Publishing their findings in the journal Nature Communications, the researchers demonstrated their own method, which is an alternative, membraneless system that works by exposing the colloidal suspension (a materials-heavy solution) to CO2.
“We are at the early stages of developing this concept. Eventually, this new method could be used to clean water for human consumption or to treat effluent from industrial facilities,” Dr Shardt stated.
“The demonstration device is made from a standard silicone polymer, a material that is commonly used in microfluidics research and similar to what is used in household sealants. While we have not yet analysed the capital and operating costs of a scaled-up process based on our device, the low pumping energy it requires, just 0.1% that of conventional filtration methods, suggests that the process deserves further research,” said Dr Shardt.
“What we need to do now is to study the effects of various compounds, such as salts and dissolved organic matter that are present in natural and industrial water to understand what impact they will have on the process. This could affect how we optimise the operating conditions, design the flow channel, and scale-up the process,” he continued.
This research was conducted last year by Shardt and Shin when they were post-doctoral researchers at Princeton University.
To read the research paper, published in Nature Communications, visit here.