Bacterial denitrification of waste water stimulated by constant electric field

The present paper considers the effect of constant electric field on the denitrification performance of the bacterium Pseudomonas denitrificans. It is shown that when constant electric field is applied on a denitrifying culture, the reduction of nitrate to elemental nitrogen runs faster than at a traditional microbial process due to the lack of a long lag-phase as it is in the case of traditional microbial dentrification. The process rate and the microbial specific activity are sensitive to the constant cathode potential if the latter is close to the one of an electro-chemical reduction process. However, evidence from the current yield in the experiments described here and from a comparison with data for electrochemical reduction without bacteria shows that a simple electrochemical process cannot explain the observed effect.