London scientists create filter to clean water for developing world

MARK BLUNDEN
AFP/Getty Images

A cheaper way of filtering contaminated water to make it safe to drink has been developed by London scientists.

The team based at Imperial College London believes the new type of plastic membrane will help provide clean drinking water in developing countries more easily and quickly.

The technology uses microscopic chains of chemicals, shaped like pasta twists, to sieve out toxins and pollutants through tiny water-attracting pores.

Its inventors say it is an improvement on the current ion-exchange technology which is more expensive and difficult to apply.

The membranes could also be used to prevent the draining of power from renewable fuel cells.

Research leader Dr Qilei Song, of Imperial’s chemical engineering department, said: “Our design hails a new generation of membranes for improving lives and also boosting

storage of renewable energy such as solar and wind power, which will help combat climate change.”

The team has successfully tested filtering small salt ions from water and removing organic molecules for municipal water treatment.

Dr Song said: “Such membranes could be used in water nanofiltration systems and produced at a much larger scale to provide drinking water in developing countries.”

They are also specific enough to filter out lithium ions from magnesium in salt water — a technique that could reduce the need for expensive mined lithium, which is the major source for lithium ion batteries.

Dr Song added: “Perhaps now we can get sustainable lithium from seawater or brine reservoirs instead of mining under the ground which would be less expensive, more environmentally friendly and help the development of electric vehicles and large-scale renewable energy storage.”

Co-first author Anqi Wang, also a PhD researcher at the department of chemical engineering, said: “The combination of fast ion transport and selectivity of these new ion-selective membranes makes them attractive for a wide range of industrial applications.”

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