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Denitrification of Water using Electrochemical Biofilms


SUMMARY From the standpoint of the conservation of environment and water resource, nitrogen removal from wastewater and nitrate polluted ground water is one of the most important problems in the European Community. The pollution is an environmental problem as well as a health hazard because of the use of groundwater and river water for drinking water production.
Biological treatment is the most common method of nitrate removal from wastewater using an anoxic filter after conventional biological treatment or an anoxic stage in activated sludge treatment. The major disadvantages of such systems are that the microorganisms are difficult to maintain, it is a slow and often incomplete process, and an external carbon source is required.
Autotrophic microorganisms are known to reduce nitrate to nitrogen while oxidising hydrogen gas. Studies have been carried out using these microorganisms and providing an external stream of hydrogen gas. Although promising, this method has been shown to be slow and have problems of incomplete denitrification. It is possible to attach autotrophic microorganisms as a biofilm to an electrode surface and the hydrogen produced by the electrolysis of water is used for the reduction of nitrate to nitrogen gas. In theory, this would be a more rapid and efficient nitrate removal method than any other to date. Small scale studies on bio-electrochemical denitrification carried out in Japan and US show intitial promise.
This study is to assess the possibility of using such an autotrophic biofilm attached to an electrode for the reduction of nitrate and to assess the extent of reduction, practicalities of the method and economics involved. If the project is successful it is envisaged to develop a bioreactor for use in wastewater and drinking water treatment.


United Kingdom

Participants (2)

Inter Euro Technology Limited Tradingas the Faraday Centre
Dun Eoghain
41 Chapelstown
Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek
501,Laan Van Westenenk
7300 AH Apeldoorn