| Abstract |
| The purpose of this study was determined nitrification and denitrification in a small scale sewage treatment plant implicated aerated up-flow Biobead(R) process. The plant constructed to treat sewage produced from an Army Camp in Korea. The existed process retrofitted to BNR process by changing recycle line from third Biobead reactor to pseudo anaerobic/anoxic reactor. The Biobead(R) process consisted of three aerated up-flow Biobead(R) reactors have been operated over 200 days. In all aerated up-flow Biobead(R) reactors, nitrification observed. The highest NH4+-N removal rate obtained at Biobead #2 and was 1.056 kg/m3 (packed media volume)/day. However, the highest conversion rate was observed in Biobead #3 reactor and was 414.9 g NO3- -N/m3 (packed media volume)/day. After retrofitting the recycle line, it was conformed that denitrification with internal carbon was carried out in pseudo anaerobic/anoxic reactor, but the T-N removal efficiency was low and 54.4%. Therefore, it was illustrated the all existed plants implicated the aerated up-flow Biobead(R) process could be upgrading to BNR process by changing recycle lines. Nitrification was observed all reactors and the highest was observed in Biobead #3. The activity was sharply decreased at below 15℃. Considering MPN test and FISH (16S sRNA), it was determined that heterotrophic biofilm was well formed in Biobead #1 and in Biobead #3, nitrifying biofilm was fully formed. Furthermore, the results of FISH were fully illustrated higher NO3--N conversion rate in Biobead #2 and #3. Especially, the relative fraction of Nitrosomonas europaea (NSM156) among nitrifying biofilm fully formed in Biobead #3 was 90.1%. |
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| Key Words |
| aerated up-flow Biobead(R) reactor, BNR, nitrifying biofilm, nitrogen removal |
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