| Title |
Influence of FA and FNA to Microbial Community in Sequencing Batch Ammonium Partial Nitrification System |
| DOI |
https://doi.org/10.15681/KSWE.2015.31.4.399 |
| Keywords |
Ammonia-oxidizing bacteria; Fluorescence in situ hybridization; Free ammonia; Free nitrous acid; Nitrite- oxidizing bacteria; Polymerase chain reaction-denaturing gradient gel electrophoresis |
| Abstract |
A sequencing batch reactor was operated under different pH conditions to see the influence of free ammonia (FA) and free nitrous acid (FNA) to microbial community on ammonium partial nitrification. Long-term influences of FA and FNA were evaluated by polymerase chain reaction-denaturing gradient gel electrophoresis and fluorescence in situ hybridization. Nitrite accumulation was successfully achieved at pH 8.2 and 6.3. The shifts in the microbial community were observed when influent ammonia concentration increased to 1 g NH4-N/L at pH 8.2, and then when pH was dropped to 6.3. Both Nitrosomonas and Nitrosospira were selected during the startup of the reactor, and eventually became dominant members as ammonia-oxidizing bacteria. The results of molecular microbiological analysis strongly suggested that the composition of microbial community was changed according to the method used to control nitrite-oxidizing bacteria. |