[Performance stability of CANON reactor and temperature impact]

In order to study long-term effect of completely autotrophic nitrogen removal over nitrite (CANON) reactor, performance stability was investigated by using synthetic inorganic ammonia-rich wastewater as raw water with a continuous flow CANON reactor. Both performances of short-cut nitrification and ANAMMOX were stable for more than one year. Under the condition that inner temperature at 35 degrees C +/- 1 degrees C, pH 7.39 and 8.01, and hydraulic retention time 3.7-5.1 h, the average total nitrogen removal load was 1.8 kg x (m3 x d)(-1), and the average and maximum total nitrogen removal efficiency were 65.09% and 81.65% respectively. Under sudden low temperature conditions, both ANAMMOX bacteria and AOB were inhibited, however, the ANAMMOX bacteria were inhibited more, which caused highly accumulated nitrite. When temperature increased to 35 degrees C as normal, the performance of CANON reactor recovered soon, which means low temperature impact will have no significant influence on stability. When the temperature reached more than 50 degrees C, the activity of ANAMMOX bacteria was completely destroyed, so high temperature must be avoided, though AOB can recovered to normal in one week.