Water, water, every where, Nor any drop to drink.

Like the Ancient Mariner, billions of people worldwide have poor access to clean drinking water. Desalination – filtering the salt from seawater using membranes with very small pores – offers one potential solution, and desalination technology is widely used in some Middle East countries. Current desalination membranes work but improvements are always needed. A recent report in the journal Nature Nanotechnology describes how very thin layers of carbon known as graphene oxide create a tunable sieve to remove salts from water.

Closer to home, and closer to practical use, is a system created by UBC engineers that uses bacteria to improve the performance of a conventional membrane filter. The system removes contaminants and pathogens by using a bacterial coating (a bio film) on the membrane surface to produce drinking water. Salt stills gets past this membrane, but this system can reuse contaminated fresh water for drinking and cooking.