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 ge l. When ethanol was supplied inside the tubular gel as an electron donor, t heir distributions overlapped in the external region of the gel. By changin g the electron donor from ethanol to gaseous hydrogen, the distribution of P. denitrificans shifted to the inside of the tube and was separated from t hat of N. europaea. The separation resulted in an increase of the oxidation rate of ammonia by 25%.