Water, water, everywhere, nor any drop to drink. This is the rhyme of the frustrated nomad who, while camping next to the ocean, is forced to head off early due to a lack of fresh H2O.
There are, of course, already a number of systems that can desalinate and purify seawater … but these all use filters which need to be regularly replaced.
Now, a new technology developed in the US looks set to make a splash on the Australian Big Lap.
Boffins at the prestigious Massachusetts Institute of Technology (MIT) have come up with a compact device that can do the job using just a tiny amount of electricity.
It works like this.
The seawater is pumped through a narrow channel between two electrically charged membranes … one positive, the other negative. As the water passes through the electrical field between the two membranes, particles such as salt molecules, viruses and bacteria are repelled into a side channel of water which is discharged and not used.
That leaves the main channel of water as being purified and relatively desalinated, but may still contain some salt ions. It then goes through an electrodialysis module to remove the last traces of salt. The water that ends up trickling out of the device’s output hose is reportedly perfectly fine to drink.
All good stuff.
The ICPWaterTech device is currently about the size of a small suitcase, weighs less than 10kg, and requires less power than a mobile phone charger, meaning that it could be powered by a portable solar panel or a battery.
In other words, it could easily fit into a grey nomad rig and not chew through too much precious power when you’re in the bush.
But now, the million dollar question.
How much clean water can it produce and how quickly? The leader of the MIT team, Professor Jongyoon Han, says the current version is capable of generating 300ml of drinking water per hour, requiring 20 watt hours of power per litre. And work is already under way to boost this rate of output.