Investigation On The Fish Detection Of The Denitrifying Phosphorus Removing Microorganism In Two-sludge Baffled Denitrifying Phosphorus System

Our country is facing the unprecedented water crisis as the economical rapid development with large population. Therefore, it is the most important problem to seek one economic, feasible water treatment technology for the wastewater treatment field. In recent years, the theory of denitrification phosphorus removal provides us new ideas and views. Moreover, it has the advantages of"one carbon dual purposes"and"energy conservation and environmental protection", which attracts more and more people's attention". According to current situation, the denitrifiction phosphorus bacteria (DPB) which have high efficiency, low energy consumption was selected as the study object in this subject. First of all, the denitrifiction phosphorus bacteria were cultured under anaerobic– anoxic approach in SBR reactor and identificated by fluoresence in situ hybridization (FISH) method. Then, the activated sludge with the function of denitrifiction phosphorus removing was operated together with oxygen biomebrane system in ABR reactor to start the two-sludge baffled denitrification phosphorus system, then the influence on the system's operation characteristics and the density of denitrification phosphorus removal bacteria caused by Influent quality and operation conditions of two-sludge baffled reactor (Hydraulic retention time and the nitration recycle flow ratio) was studied. The main results are as follows:1. The FISH detection showed that Rhodocclus sp. and relative microbial strains became the dominant bacteria gradually during the cultivation of DPB using nitrate as electron acceptor and occupied up to 29%(±3%)proportion, while Pseudomonas sp. were not detected.2. Influent quality had great influence both on the Rhodocclus sp. and relative microbial strains and the performance of the system. Influent quality that COD was 250 mg/L, CODcr/TN was 5.6, and the concentration of phosphate was about 5 mg/L was beneficial to the Rhodocclus sp. and relative microbial strains. The Rhodocclus sp. and relative microbial strains became the dominant bacteria, occuping up to 26%(±7%)proportion under the above influent quality condition, and the reactor showed good performance of nitrogen and phosphorus removal operating under above Influent quality.However, it was detrimental to the Rhodocclus sp. and relative microbial strains under the influent quality condition with high CODcr/TN or the low CODcr/TN. The quantity of the Rhodocclus sp. and relative microbial strains slowed down gradually, simultaneously the operation performance of the system slowed down gradually. The reactor showed good performance of nitrogen removal and bad performance of phosphorus removal under the influent quality condition with high CODcr/TN, while the reactor showed bad performance of nitrogen and phosphorus removal under the influent quality condition with low CODcr/TN.3. Hydraulic retention time had a little influence on the Rhodocclus sp. and relative microbial strains, while hydraulic retention time had great influence on the performance of the system, the short hydraulic retention time caused the effect of systems operation worsening.4. The nitration recycle flow ratio had remarkable influence on the Rhodocclus sp. and relative microbial strains and the performance of the system.The quantity of Rhodocclus sp. and relative microbial strains droped immediately under the high percentage of nitration reflow, simultaneously the performance of phosphorus removal droped immediately.