Electrodenitrification of Water Using the Enzyme Nitrate Reductase

Nitrate is a worldwide contaminant that causes environmental (eutrophication) and human health (methemoglobinemia, cancers) concerns. Very few techniques are available to eliminate it from natural environment and they suffer from major drawbacks, such as production of unwanted byproducts (toxins or brine). This project develops a new approach that could overcome these disadvantages and demonstrates the feasibility of using an enzyme and a mediator to transfer the electrons from different types of electrode to nitrate. The main advantage of this system is the production of a gaseous product, which is probably nitrogen gas, an environmentally safe gas. The results are promising since no special conditions are required to run the system. Indeed, the reduction takes place in an air atmosphere, at room temperature and the two electrodes do not need to be separated. This study will interest anyone who works on nitrate removal from aqueous environments but also on any contaminant that can be reduced or oxidized since the technique may be adapted. This work was awarded most outstanding thesis of the year 2001 from the University of Northern Iowa.