Image credit: University of LimerickAs researchers continue to look for new and better ways to meet clean water demands worldwide, a recent study appearing in the journal Nature Communications details a water filtration process using carbon dioxide that consumes 1,000 times less energy than traditional processes.

The study — led by Dr. Orest Shardt (University of Limerick, Ireland) together with Dr. Sangwoo Shin (now at University of Hawaii, Manoa) — shows that instead of expending energy to push water through porous membranes to trap and remove particles, the membraneless method exposes particles to CO₂.

"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 analyzed the capital and operating costs of a scaled-up process based on our device, the low pumping energy it requires, just 0.1 percent 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 optimize the operating conditions, design the flow channel and scale-up the process," he continued.

In addition to uses in the mining, food and beverage production, pharmaceutical manufacturing and water treatment industries, researchers also believe that the new method could be used to remove bacteria and viruses without chlorination or ultraviolet treatment.

"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 said.