A team of researchers of LEQUIA led by Dr. Jesús Colprim has developed a system able to treat groundwater polluted with different nitrate levels, at low energy cost and without producing additional waste products. The technology has led to the submission of a European patent and the publication of papers in international high impact scientific journals such as Environmental Science and Technology and Bioresource Technology. It is based on the capacity of some bacteria to reduce nitrates to nitrogen gas.
Main innovations are working with exoelectric (electrically active) bacteria, so that it is not necessary to add organic matter, and adjusting the electrode potential with an electronic device (a potentiostat) fed with a photovoltaic panel. This allows solving the main limitation of such systems: treating groundwater polluted with different nitrate levels at a reasonable cost.
The technology is applicable to both groundwater and wastewater, and it can be developed at industrial scale. Tests were carried out with groundwater from wells in the town of Navata (Alt Empordà, Girona): waters with nitrate levels higher than 150 mg/l were successfully treated.