Study of Factors Influencing Ammonia Nitrification

NH_3-N,an important water quality index,is limited in discharge stringently.The ammonia concentration is very low,species of nitrifying bacteria and characteristic of nitrification kinetic may be different.The effects of factors such as temperature,pH and alkalinity on nitrification were discussed with enriched nitrobacteria.The results show that the influence of temperature on nitrification at low ammonia concentration was stronger than that at high concentration system.The alkaline condition is favorable to achieve complete nitrification of low ammonia concentration.The nitrification rate of high concentration ammonia is maximum at pH of 8 or(Alk/N) of 9.19,and that of low concentration ammonia achieve maximum at pH of 9 or(Alk/N) of 38.39.The three factors all had prominent effects on nitrification at high level.Whereas, Compared with temperature,pH and alkalinity were the main factors influencing ammonia nitrification at low ammonia concentration.