Isolation and denitrification characteristic of an aerobic denitrifier

Nitrification and denitrification are two main stagesof nitrogen removal process in wastewater treatment.Conventional systems for the treatment of nitrogen-containing wastes at least need two facilities.This isbecause they are based on the principle that nitrifica-tion is an aerobic process,whereas denitrification is re-stricted to anoxic conditions.Operation of the single re-actor system is simple and cost effective.Simultaneousnitrification and denitrification within biofilm can occuronly un…

Isolation and denitrification characteristic of an aerobic denitrifier

Aerobic denitrifiers were enriched by activated sludge cultivation method. By this way, 105 strains were isolated from the activated sludge and 25 strains were confirmed to be capable of obtaining energy by deoxidization of nitrate to nitrogen gas under aerobic condition. The characteristic of one denitrifier, Pseudomonas chloritidismutans strain, was particularly studied due to its higher nitrogen removal rate. It was found that Pseudomonas chloritidismutans can use nitrite, nitrate and oxygen for aerobic respiration in liquid medium, and the pH increased and ORP decreased by activated denitrifier. When they used nitrite or nitrate for respiration, nitrogen removal effect was high and nitrite could be reduced more efficiently than nitrate. Denitrification process was accomplished faster when both nitrite and nitrate existed in the medium compared to each of which existed alone. Particularly, at denitrifying activity, the nitrogen removal rate of strain was not affected by the DO concentration in the culture media.