[LUM#2] An Ocean to Drink

Turning seawater into drinking water using an environmentally friendly and cost-effective process—that is the challenge taken on by researchers and students at Polytech and Montpellier Engineering.

Access to drinking water is a major challenge for millions of people around the world. And global warming isn’t helping matters: according to UN experts, the planet is expected to face a 40% global water shortage by 2030. Yet water covers 70% of the Earth’s surface… in the form of seas and oceans. Undrinkable? Perhaps not.“Since the 1950s, we’ve known how to convert saltwater into freshwater using intensive desalination processes,” explains Marc Héran, a professor at Polytech and a researcher at the European Institute of Membranes (IEM). The problem: desalination plants consume enormous amounts of energy.“Most of that energy comes from oil, which is not sustainable from an ecological standpoint.”

Choosing Solar Energy

The solution? A solar-powered desalination unit. Called Dunetec, this innovative technology is being developed by researchers and students at Polytech in collaboration with Montpellier Engineering.“Using solar energy, we heat seawater to cause it to evaporate and then condense. The end result is fresh water,explains Jean Pierre Mericq, a researcher atIEM a professor at Polytech. It’s a simple principle but a real technological challenge:“We had to optimize the evaporation process to produce as much fresh water as possible while using a minimum of energy and taking up as little spaceas possible,” explains André Chrysochoos of the Mechanics and Civil Engineering Laboratory, who also teaches at Polytech.

A dozen students from various programs at the engineering school helped tackle the challenge.“This is a transdisciplinary project that requires expertise in the field of water, as well as in modeling, electronics, and information processing,” the instructors emphasize. This collaboration has resulted in a prototype that is currently being tested in Port-la-Nouvelle.

A Local Solution to a Global Shortage

Next step: offer this technology to regions with high levels of sunshine and access to the sea. The initial target areas are southern Spain and the Greek islands.“A desalination unit should be able to meet the drinking water needs of a village of 200 people,” explains Laurent Trémel, president of Montpellier Engineering, who highlights one of Dunetec’s advantages: ease of use.“Maintenance and upkeep can thus be handled independently by local communities.”

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