Study On Phoasshorus Removal Characteristics Of Polyphosphate Accumulating Organisms And Glycogen Accumulation Organisms And Their Subgroup

Compared with traditional biological phosphorus removal,the enhanced biological phosphorus removal process not only saves costs,but also achieves the purpose of simultaneous nitrogen and phosphorus removal.In view of the advantages of enhanced biological phosphorus removal and phosphorus removal microorganisms,this project selects the main influencing factors for the competition between polyphosphate bacteria and polysaccharide bacteria: carbon source,inlet C/P,inlet C/N,temperature and inlet p H The object,through the comparison of the batch test results in each group,examined the effects of these 5 factors on the nitrogen and phosphorus removal of the system.Based on 16 S r RNA for microbial diversity sequencing,the differences and identification of polyphosphate and polysaccharide bacteria and their subgroups under various factors were carried out.The purpose of this study was to reveal the mechanism of the effects of enhanced competition between polyphosphate and polysaccharide bacteria and their subgroups in biological phosphorus removal.In order to find the most suitable carbon source for the growth of polyphosphate bacteria,influent C/P,influent C/N,temperature and influent p H.Anaerobic/aerobic operation is used to acclimate the activated sludge to enrich the phosphorus accumulating bacteria and glycan bacteria and their subgroups.After30 consecutive days of start-up of the reactor and acclimation of the sludge,the system tended to a steady state.The system has a good removal effect of pollutants during the enrichment.Through comparative experiments using acetic acid,propionic acid and glucose as carbon sources,the results show that the system has good nitrogen and phosphorus removal efficiency,but the amount of released phosphorus is quite different,and the amount of released phosphorus is: acetic acid> propionic acid> glucose.When glucose was used as the carbon source,the anaerobic section removed more TN,but the relative abundance of Betaproteobacteria was the smallest.When using acetic acid as the carbon source,the relative abundance of Betaproteobacteria was thelargest,and propionic acid was somewhere in between.When propionic acid was used as the carbon source,the microbial community diversity was the lowest,but its community structure was similar to that of acetic acid.When acetic acid was used as the carbon source,the content of glycogen was the least,and the bacterial form in the sludge was rich.Influent TP concentration was in the range of 2mg/L～6ml/L.With the increase of TP content in the influent,the amount of phosphorus released during the anaerobic phase increased significantly,the TP removal rate increased slightly,the microbial community diversity gradually decreased,and the sludge Filamentous fungi gradually appear.When the influent C/P was 66.67,the TP removal rate was higher,but the removal effect on nitrogen was the worst,the glycogen content was the least,and the microbial community diversity was the lowest.Betaproteobacteria and Sphingobacteriia are dominant bacteria in the system.The relative abundance of Betaproteobacteria is the largest when C/P is 100,and its abundance gradually decreases as C/P continues to decrease.The concentration of TN in the water is in the range of 20mg/L～60mg/L.With the increase of the content of TN in the water,the nitrogen removal effect is always maintained,but the amount of phosphorus released during the anaerobic phase is significantly reduced,and the microbial community diversity is slightly Reduced,it is also more difficult to observe bacilli in the sludge.The relative abundance of Betaproteobacteria was the smallest when the C/P of the influent was 6.67,and the glycogen content was the highest.As the carbon to phosphorus ratio decreased,Betaproteobacteria and Sphingobacteriia were still the dominant bacteria,and the relative abundance of Alphaproteobacteria and Gammaproteobacteria was slightly reduced.Increasing temperature still has a good effect on the removal of COD,but the phosphorus removal ability and nitrogen removal capacity of the system decreased significantly,and the phosphorus absorption rate in the aerobic section was significantly weakened.The amount of phosphorus released in the anaerobic stage is:20℃>15℃>25℃>30℃>35℃.As the temperature gradually increased from 20℃ to35℃,the relative abundance of Betaproteobacteria gradually decreased.At 35℃,the glycogen content was the highest,and the relative abundance of Gammaproteobacteria was the largest,but the diversity of microbial communities was the lowest,and the relative abundance of Betaproteobacteria was also the smallest.When the p H value of the feedwater is 6.5 and 7,the system has a good effect of removing pollutants;when the p H value of the feedwater is 6,the glycogen content is the highest,but the removal effect of nitrogen is slightly reduced;when the p H value of the feedwater is At 7.5 and 8,the nitrogen and phosphorus removal efficiency of the system decreased sharply,and the phosphorus absorbing capacity of the aerobic section polyphosphate bacteria decreased significantly.The order of microbial community diversity is: p H=7>p H=6.5>p H=6>p H=7.5>p H=8.The relative abundance of Betaproteobacteria was the highest when the p H value of the influent was 7,and the relative abundance of Alphaproteobacteria and Gammaproteobacteria increased significantly with the increase of p H value,and filamentous bacteria appeared in the sludge.