In order to further explore the mechanism of denitrifying phosphorus removal,the growth characteristics and denitrifying phosphorus removal characteristics of a typical denitrifying phosphate accumulating bacteria(DPB...In order to further explore the mechanism of denitrifying phosphorus removal,the growth characteristics and denitrifying phosphorus removal characteristics of a typical denitrifying phosphate accumulating bacteria(DPB) which was isolated by previous experiment were studied.The effect of different electron acceptors on the efficiency of nitrogen and phosphorus removal was investigated by pure bacteria and reactor statics simulation tests.The growth curve of the DPB was typical,and its incubation period was less than 1 h and the logarithmic phase about 14 h.The result showed that the stain could utilize both nitrite and nitrate as different electron acceptors to take up phosphorus.And there was a good linear correlation between P removal and NO-3-N removal during phosphorus removal process.The sensitivity to nitrite of the strain was low.The effect of electron acceptors on phosphorus removal was not significant.The efficiency of removal for phosphorus and the nitrate was both above 60%,and that for nitrite was 100%.展开更多
Denitrifying phosphorus accumulating organ- isms （DPAOs） using nitrite as an electron acceptor can reduce more energy. However, nitrite has been reported to have an inhibition on denitrifying phosphorus removal. In ...Denitrifying phosphorus accumulating organ- isms （DPAOs） using nitrite as an electron acceptor can reduce more energy. However, nitrite has been reported to have an inhibition on denitrifying phosphorus removal. In this study, the step-feed strategy was proposed to achieve low nitrite concentration, which can avoid or relieve nitrite inhibition. The results showed that denitrification rate, phosphorus uptake rate and the ratio of the phosphorus uptaken to nitrite denitrified （anoxic P/N ratio） increased when the nitrite concentration was 15 rag. L-1 after step- feeding nitrite. The maximum denitrification rate and phosphorus uptake rate was 12.73 mg NO2-N.g MLSS- 1· h- 1 and 18.75 mg PO34--P- g MLSS- 1. h- 1, respec- tively. These rates were higher than that using nitrate （15 mg. L-l） as an electron acceptor. The maximum anoxic P/N ratio was 1.55 mg PO43- -Pmg NO2-N-1. When the nitrite concentration increased from 15 to 20 mg NO2 -N ~ L-I after addition of nitrite, the anoxic phosphorus uptake was inhibited by 64.85%, and the denitrification by DPAOs was inhibited by 61.25%. Denitrification rate by DPAOs decreased gradually when nitrite （about 20 mg · L-1） was added in the step-feed SBR. These results indicated that the step-feed strategy can be used to achieve denitrifying phosphorus removal using nitrite as an electron acceptor, and nitrite concentration should be maintained at low level （ 〈 15 mg. L-1 in this study）.展开更多
文摘In order to further explore the mechanism of denitrifying phosphorus removal,the growth characteristics and denitrifying phosphorus removal characteristics of a typical denitrifying phosphate accumulating bacteria(DPB) which was isolated by previous experiment were studied.The effect of different electron acceptors on the efficiency of nitrogen and phosphorus removal was investigated by pure bacteria and reactor statics simulation tests.The growth curve of the DPB was typical,and its incubation period was less than 1 h and the logarithmic phase about 14 h.The result showed that the stain could utilize both nitrite and nitrate as different electron acceptors to take up phosphorus.And there was a good linear correlation between P removal and NO-3-N removal during phosphorus removal process.The sensitivity to nitrite of the strain was low.The effect of electron acceptors on phosphorus removal was not significant.The efficiency of removal for phosphorus and the nitrate was both above 60%,and that for nitrite was 100%.
文摘Denitrifying phosphorus accumulating organ- isms （DPAOs） using nitrite as an electron acceptor can reduce more energy. However, nitrite has been reported to have an inhibition on denitrifying phosphorus removal. In this study, the step-feed strategy was proposed to achieve low nitrite concentration, which can avoid or relieve nitrite inhibition. The results showed that denitrification rate, phosphorus uptake rate and the ratio of the phosphorus uptaken to nitrite denitrified （anoxic P/N ratio） increased when the nitrite concentration was 15 rag. L-1 after step- feeding nitrite. The maximum denitrification rate and phosphorus uptake rate was 12.73 mg NO2-N.g MLSS- 1· h- 1 and 18.75 mg PO34--P- g MLSS- 1. h- 1, respec- tively. These rates were higher than that using nitrate （15 mg. L-l） as an electron acceptor. The maximum anoxic P/N ratio was 1.55 mg PO43- -Pmg NO2-N-1. When the nitrite concentration increased from 15 to 20 mg NO2 -N ~ L-I after addition of nitrite, the anoxic phosphorus uptake was inhibited by 64.85%, and the denitrification by DPAOs was inhibited by 61.25%. Denitrification rate by DPAOs decreased gradually when nitrite （about 20 mg · L-1） was added in the step-feed SBR. These results indicated that the step-feed strategy can be used to achieve denitrifying phosphorus removal using nitrite as an electron acceptor, and nitrite concentration should be maintained at low level （ 〈 15 mg. L-1 in this study）.
