China discovers unprecedented water and salt separation technology with purity up to 99.9%

According to Interesting Engineering, researchers in China have revealed a new, extremely efficient technology for separating oil and water mixtures.

The oil and water mixture will separate automatically if left for a long time. However, in industrial production processes, this process must be accelerated and is extremely difficult.

Recycling involves a variety of methods, including centrifugation, oil skimming, and chemical reactions. However, these traditional methods are often time-consuming, energy-intensive, and inefficient.

New technology Janus Channel of Membranes helps separate oil and water mixtures quickly.

Researchers at Zhejiang University, China, have developed a new technology, based on the membrane filtration method , called Janus Channel of Membranes (JCM) to solve the above difficulties.

JCM is named after the ancient Roman god Janus, who had two faces. The name symbolizes the technology's ability to separate oil and water simultaneously.

The new JCM technology uses two semi-permeable membranes : one hydrophilic and one hydrophobic. The membranes are separated by a trough that can be adjusted in width from 4 to 125 mm, to optimize the separation process, the team's research paper said.

Due to the narrow space between the two membranes, the recovery rate is very high, up to 97% for oil and 75% for water, with minimal impurities.

The small oil droplets collide and then merge, forming larger droplets that pass through the hydrophobic membrane and flow into an outer reservoir. At the same time, water molecules slide through the hydrophilic membrane and flow into another reservoir.

"When an oil and water emulsion has to circulate through the gap, water will pass through the hydrophilic membrane and the increased oil concentration in the emulsion will increase the oil permeation rate through the hydrophobic membrane ," the authors explain in the research paper.

While conventional separation technologies typically separate either oil or water from an emulsion, this new technology allows researchers to recover both components.

This simple but ingenious approach has shown remarkable results. In laboratory tests, the technology recovered nearly 97% of the oil and 75% of the water from the mixture. The oil and water separated were extremely pure, reaching 99.9%.

Interestingly, the technology has the potential to be scaled up to larger scale operations . Industries such as petrochemicals, metallurgy, food and pharmaceuticals generate large volumes of oily wastewater that is difficult to treat. Therefore, JCM has the potential to significantly improve the sustainability of wastewater treatment.