Study Of Influencing Factors On Phosphorus Removal In AAO And Oxidation Ditch Anaerobic Pool

The test analysis in this paper has compared water quality and anaerobic phosphorus release of anaerobic reactor of the traditional AAO and the Carrousel 2000 oxidation ditch with the leading anaerobic pool before and after the suspension of suspended film.At the same time,anaerobic phosphorus release comparative analysis was performed on the different inflow TP concentration,the ratio of different suspended packing ratios,and whether there is activated sludge.Finally,high-throughput sequencing of biofilm microorganism and anaerobic activated sludge microorganism can be used to provide a reference for future research.Through the above research,the following results are obtained:（1）In continuous flow process test,the average outflow concentration of AAO and Oxidation Ditch systems can meet the grade B standard of the pollutant discharge standard of urban sewage treatment plant,and the average outflow concentration of COD,TN and NH₄⁺-N of two systems have reached the grade A standard.Before adding the suspended film suspension fillers,AAO process system has an average phosphorus release rate of 0.668 mg/L,and the average phosphorus release rate of the oxidation ditch process system is 0.639 mg/L.After adding the suspended film suspension filler,AAO process system has an average phosphorus release rate of-0.783 mg/L,and the average phosphorus release rate of the oxidation ditch process system is-0.783 mg/L.After adding hang membrane suspended filler,the anaerobic reactor of AAO and oxidation ditch are showing“anaerobic phosphorus absorbing”phenomenon,which is caused by adding suspended film suspension fillers.（2）By 18 groups of working condition experiment,it argues that there may be some microbials that can use phosphate in the mixture under anaerobic conditions and lead to TP concentration lowering in the mixture.From the experiment consequence,when filling ratio is stable and filling activated sludge,the average“anaerobic phosphorus absorbing”rate have not transformation law,when inflow TP concentration is same,the average“anaerobic phosphorus absorbing”rate is higher when filling ratio is higher under without activated sludge condition,and there is a significant difference between the non-filler and the filling group,the former is anaerobic phosphorus release,and the latter is“anaerobic phosphorus absorbing”under adding activated sludge condition.when inflow TP concentration and filling ratio are same,it is a significant difference whether there was no activated sludge,the average“anaerobic phosphorus absorbing”rate in working of without activated sludge is higher than working of adding activated sludge.（3）When suspended membrane packing and the anaerobic activated sludge are added simultaneously at the same filling ratios,the rate of COD degradation in the first180 min increased along with the increase of inflow TP concentration whether there was no activated sludge.When only the suspended membrane is added and the TP concentration in the water is the same,the rate of COD degradation in the first 180 min is negatively correlated with the average“anaerobic phosphorus absorbing”rate.The average“anaerobic phosphorus absorbing”rate increases along with the increase of inflow TP concentration,while on this condition the rate of COD degradation decreases.When the TP concentration and filling ratio of suspended membrane are the same,the rate of COD degradation in the first 180 min is higher in scenario with activated sludge,but the average“anaerobic phosphorus absorbing”rate is higher in the scenario without activated sludge,they are negatively correlated.（4）Through detecting the TP concentration in the air at the top of the anaerobic reactor of suspended membrane packing,it is revealed that during the anaerobic reaction with suspended fillers,the phosphide in the mixture is released into the gas phase in the form of gaseous phosphorus substances with the help of biochemical reaction of some microorganisms.Thus the phosphide is separated from the mixed liquor,and this is a major cause of anaerobic“phosphorus absorption”.（5）High-throughput sequencing analysis results show that the population structure of biofilm microbes is similar to that of activated sludge microbes,but there is also some differece.A few microbial species only have a large proportion in biofilm,such as Tolumonas,Desulfomicrobium,Sulfurospirillum.Through high throughput sequencing and subsequent analysis,it is believed that Clostridium,Lactococcus,Desulfomicrobium,Sulfurospirillum,Obscuribacterales,Micropruina may be the key microorganism of anaerobic phosphorus removal.