Investigation of nitritation achieved in a bio-ceramic reactor

A bio-ceramic reactor used for treatment of low concentration ammonia nitrogen wastewater was operated to study the properties and stability of nitritation. With influent hydraulic loading of 0.6 m³/(m²·h); gas/water ratio of (3-5):1; temperature of 20-25°C; COD loading of 106-316 mg/L and NH₄⁺-N loading of 42.78-73.62 mg/L, the average ammonia nitrogen removal efficiency of 80.91% was obtained, and the nitrite nitrogen accumulation rate was about 91%-99%. The results about bacteria counting at the different zones of the reactor and the change of several inorganic nitrogen compounds along the influent flow show that the stable nitrite accumulation can be achieved in the reactor at ambient temperature by controlling the dissolved oxygen.