From seawater to drinking water, with the push of a button

Boston - Massachusetts Institute of Technology researchers have created a portable desalination unit that can remove particles and salts simultaneously to generate drinking water.

The user-friendly unit, which weighs less than 10 kilograms and does not require filters, can be powered by a small, portable solar panel.

The suitcase-sized device can be purchased online for around $50. It automatically generates drinking water that exceeds World Health Organisation quality standards.

The technology is packaged into a user-friendly device that runs with the push of one button. The device is the culmination of a 10 years research.

Unlike other portable desalination units that require water to pass through filters, this device utilises electrical power to remove particles from drinking water. Eliminating the need for replacement filters greatly reduces the long-term maintenance requirements.

This could enable the unit to be deployed in remote and severely resource-limited areas, such as communities on small islands or aboard seafaring cargo ships. It could also be used to aid refugees fleeing natural disasters or by soldiers carrying out long-term military operations.

Commercially available portable desalination units typically require high-pressure pumps to push water through filters, which are very difficult to miniaturise without compromising the energy-efficiency of the device.

The researchers designed the device for non-experts, with just one button to launch the automatic desalination and purification process. Once the salinity level and the number of particles decrease to specific thresholds, the device notifies the user that the water is drinkable.

The researchers also created a smartphone app that can control the unit wirelessly and report real-time data on power consumption and water salinity.

After running lab experiments using water with different salinity and cloudiness levels, they field-tested the device at Boston's Carson Beach.

They set the box near the shore and tossed the feed tube into the water. In about half an hour, the device had filled a plastic drinking cup with clear, drinkable water.

The resulting water exceeded WHO quality guidelines and the unit reduced the number of suspended solids by at least a factor of 10. Their prototype generates drinking water at a rate of 0.3 litres per hour and requires only 20 watts of power per litre.

MIT is pushing its research to scale up that production rate. One of the biggest challenges of designing the portable system was engineering an intuitive device that could be used by anyone.

The academics want to improve its energy efficiency and production rate through a startup he plans to launch to commercialise the technology.