Abstract
A novel biological treatment system using Paracoccus denitrificans, which do not require organic compounds , was developed for denitrification. In this method, a porous carbon electrode was used as an electron donater source. Tetramethylhydroquinone was used as an electron transfer mediator between the electrode and respiratory chain of the bacterial cell. Nitrate is reduced to nitrogen gas by the biocatalytic reaction in anaerobic condition. The denitrification efficiency in batch- and flow type cells was compared. The respective denitrification rates, which were calculated on the basis of the nitrate reduction within the initial 24 h, were estimated 114 and 35 mg of N per hr for 1m2 of the electrode geometric area. It was found that the commercially available carbon felt is useful as an immobilization carrier of denitrifying bacteria to develop a large-scale nitrogen removal system.
