An experimental project near Seville is developing an environmentally friendly and efficient way to purify sewage water. The traditional method of purifying waste water uses underground microorganisms, but researchers at iMETland have made a striking improvement by creating a way for the bacteria to create electricity. These so-called ‘electroactive bacteria’ can purify water up to ten times faster than conventional methods, providing clean water with no energy costs and no residual pollution.
The water is collected in a septic tank, and then it flows through a biofilter where the bacteria attach to the surface of a special material that has powerful conductivity. This creates a reaction where the electrons flow freely through the bacteria, and it allows them to decompose the organic matter quickly. One unit of the system can provide up to 25,000 litres per day, which is enough to cover the needs of a small community.
The project is run by the Centre for New Water Technologies (CENTA), a non-profit research institution, with similar projects being carried out in Mexico, Argentina and Denmark. Further research is underway to find the best materials for this potentially groundbreaking technology which can be used anywhere in the world and in any climate. It is expected that this discovery will be particularly helpful to purify water in developing countries, because it does not require a source of energy.