RESUMO
Start-up and process control of a pilot-scale anaerobic ammonium-oxidizing (Anammox) bioreactor were studied at ambient temperature. Inoculated with a mixture of nitrification-denitrification sludge, nitritation sludge, anaerobic floc sludge and anaerobic granular sludge, the pilot-scale Anammox bioreactor was successfully started up within 255 days at 5 degrees C-27 degrees C. The nitrogen removal rate reached 1.30 kg/(m3 x d). Three facets were taken into account to facilitate the process initiation. First, in terms of alkalization in Anammox, influent pH was kept at about 6.8. Besides, nitrite concentration was kept as low as 13-36 mg/L. Finally, 2% (volumetric ratio) of Anammox sludge from lab-scale bioreactors was supplemented to the pilot-scale one.