Abstract：To investigate the mechanism and pathways of nitrogen removal, four microelectrodes of NH4+, NO2-, NO3- and pH were used to explore the transform of nitrogen compounds inside the granules obtained from the anaerobic rotating biological contactor (AnRBC) under different operating conditions. The results show that when the substrate concentration is sufficient, the concentration of ammonia and nitrite are decreased simultaneously from the granular surface with characteristic reaction of Anammox. When the ammonia concentration is limited in the system, ammonia is consumed by Anammox in the outer layer(0-1 200 μm), while in the inner layer(1 200-2 500 μm), nitrogen removal is by denitrification of nitrite. When there is only NOx- in granules, the pathway of nitrogen removed shows characteristic of denitrification. There are at least two nitrogen removal pathway of Anammox and autotrophic denitrification in the AnRBC system.
2012, Vol. 33 
