Abstract:

This paper introduces the heterotrophic nitrifier strain Y1 separated from activated sludge，with optimized nitrifying conditions of C/N 9.6，temperature 30℃，initial pH value 9.0 and shaking speed 250rpm，under which the 152.88mg/L NH+4-N get degraded to 4.02mg/L in 8 hours，without accumulation of intermediate products，such as nitrite and nitrate. It is also found that the bacterial strain Y1 acts as heterotrophic nitrification，but also have the ability to use NO-3-N as sole nitrogen source in aerobic conditions for denitrification，with rate of 99.05% as degradation within 40 hours for initial concentration of 196mg/L NO-3-N.