Katharine Sanderson | May 21, 2012 | guardian.co.uk | Shared as an educational material
We’re a thirsty species. Humans can’t survive without fresh, clean, drinking water, yet we sprang to life on a planet where 97.5% of water is useless to us.
What’s left for us to drink is becoming more and more polluted by agriculture, industry and poor water-management. By 2030, 3.9 billion people (47% of the predicted population) won’t have access to clean water.
There is a tiny solution to this large problem: nanomaterials can strip water of toxic metals and dangerous organic molecules, or turn salt water into fresh water. There are also plenty of other nanotech solutions in development.
“Nanotechnologies that have the best chance are ones we can integrate into existing systems,” says Mamadou Diallo, an environmental engineer at the California Institute of Technology. That means, for example, membranes enhanced with nanoparticles that can slot seamlessly into water treatment plants.
The Nametech project, which is co-funded by the European Commission and the University of Applied Sciences Northwestern Switzerland, is enhancing filters already used in water treatment plants with nanoparticles that do specific jobs.
“We’re adding a wide range of nanoparticles,” says project manager Thomas Wintgens of the University of Applied Sciences Northwestern Switzerland in Muttenz. These include:
• Biomagentite, an iron mineral, to get rid of chlorinated organic molecules and some toxic metals.
• Silver to kill bacteria.
• Nanoparticles of titanium dioxide to break down common organic contaminants such as hormones, pharmaceuticals, or manure – all they need to operate is some light to shine on them when they are in the water.
• Titanium dioxide, which is already widely used in paints and sunscreens so, in principle, the technology is cheap.
Nametech is running a small pilot plant to test the membranes. Each 20cm module can process around a cubic metre of water every hour. But, like other new technologies, it needs to be proven beyond the lab.
Rob Lammertink of the University of Twente, the Netherlands, says there is interest from industry for nanotechnology water treatments, but it is still early days. He heads the nanotechnology in water group of a large consortium, NanoNextNL, and predicts that, perhaps in five or 10 years, nanotech water treatments might be used on a large scale.