Oil and water are difficult to separate without leaving some impurities
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Mixtures of oil and water have long posed a challenge when it comes to efficient separation methods. However, a recent development by Hao-Cheng Yang and his team at Zhejiang University in China offers a promising solution. Through the use of two membranes – one hydrophobic and one hydrophilic – the team has successfully managed to achieve a purity greater than 99.9 per cent in separating oil and water mixtures.
Traditionally, methods such as centrifugation, mechanical skimming, and chemical treatments have been employed to separate oil and water mixtures. While semipermeable membranes offer a simple solution, they often leave behind impurities, leading to a less than ideal separation process.
Yang and his team’s approach involves pumping the mixture into a thin channel between the two membranes. This confined space allows for better accumulation and removal of oil droplets by the hydrophobic membrane, while simultaneously enabling the hydrophilic membrane to pass water through. The result is a continuous and efficient separation process that ensures both clean oil and water are recovered.
According to Yang, the key to their success lies in the feedback loop created by the changing concentration of components in the mixture. As the channel width is narrowed, the total oil recovery increases significantly, reaching up to 97 per cent, while water recovery also sees a substantial improvement, going up to 75 per cent. The purity of the recovered oil and water exceeds 99.9 per cent, with minimal waste left behind.
With such promising results, Yang and his team are now exploring opportunities to scale up their method for industrial applications. The simplicity and efficiency of the process make it a viable solution for dealing with industrial waste in a cost-effective and environmentally friendly manner.
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