Nanotechnology makes cheap, improved, water filters

Researchers have developed nano-scaled membranes that could potentially filter contaminants out of water faster and cheaper than current methods. Baoxia Mi, an assistant professor of environmental engineering at the university of California, Berkeley, is developing a water filter comprised of membranes made up of layers of graphene 100,000 times thinner than a strand of human hair.

"We made it from graphite, which is a material that we use in pencils for example, so it's cheap and relatively abundant. So we can use that and the process that we use to make from the graphite to the graphene oxide is actually quite scalable," said Mi.

By scalable, Mi means that these membranes could potentially be adapted to filter water from a household faucet, as well as large systems used to treat waste water on an industrial scale. The membranes are much like a maze for water molecules. The water enters the maze and passes through a series of layers separated by spaces specifically designed to remove different types of contaminants.

"In order to remove different targeted molecules, the most direct way of thinking about it is to control the spacing that we have between the layers," added Mi. Another advantage to these graphene oxide filters is the rate at which water can pass through them, which Mi says is up to five magnitudes higher than conventional filters thanks to the unique properties of the carbon base membranes.

The researchers are currently fine tuning their filters. They hope their work in the lab will ultimately lead to real world solutions to the ever growing concerns surrounding access to clean affordable water, especially in the developing world.