Distribution of Nitrosomonas europaea and Paracoccus denitrificans immobilized in tubular polymeric gel for nitrogen removal.

To improve the cooperative removal of nitrogen by Nitrosomonas europaea and Paracoccus denitrificans, we controlled their distribution in a tubular gel. When ethanol was supplied inside the tubular gel as an electron donor, their distributions overlapped in the external region of the gel. By changing the electron donor from ethanol to gaseous hydrogen, the distribution of P. denitrificans shifted to the inside of the tube and was separated from that of N. europaea. The separation resulted in an increase of the oxidation rate of ammonia by 25%.