Determination of autotrophs kinetics parameters and its affecting factors in nitrification system

The expression of autotrophs growth kinetics indicates that autotrophs maximum growth rate can be determined by analyzing the varying trend of nitrate nitrogen concentration with time changing under conditions of lower initiative nitrate nitrogen concentration and autotrophs concentration. The batch activated sludge method was used to determine autotrophs maximum growth rate. In addition, affecting factors were also investigated. The results show that autotrophs maximum growth rates varied from 0.32 d-1 to 0.54 d-1 and the average rate was 0.45 d-1 at 20°C. The factors, such as temperature, dissolved oxygen concentration, autotrophs concentration, initiative ammonia concentration and organic substance had remarkable influences on autotrophs maximum growth rate.