Study On The Effect Of Sidestream Phosphorus Recovery Process On Main Biological Phosphorus Removal Efficiency

In current sewage treatment process,the problem of excessive phosphorus?P?load in the effluent is frequent,which makes the eutrophication of the receiving water body serious,but at the same time,P is a non-renewable resource that needs to be recycled.The sidestream P recovery process can effectively solve the problem of P load over standards and realize the recycling of P resources in wastewater.Studies have shown that excessive stripping of P from the mainstream system can cause the collapse of the entire biological P removal system,resulting in the suspension of the sustainable recycling chain of P resources.Therefore,in order to scientifically and effectively realize the sidestream P recovery process,it is necessary to understand the influence of the sidestream operation on the biological P removal system and explore the operating conditions applicable to the sidestream P recovery.In this project,the SBR reactor was operated by anaerobic/aerobic alternate model,and the experimentally configured sewage was used as the influent.The experiment of recovering P from the anaerobic phosphorus-rich supernatant was carried out within 30 d,and the second cycle of each day was used as the lateral flow cycle.In the sidestream process,the effects of different chemical agents,oxygen-containing carbon sources,carbon source limitation on biological phosphorus removal characteristics,phosphorus recovery potential and microbial flora structure level were investigated,and combined with extracellular polymerization.The reason for the phosphorus storage function of the material?EPS?is further analyzed.The results indicates that:when the short term stripping ratio reaches 100%,113%¹41%of influent P recovery can be achieved,and COD and NH₄⁺removal are not affected.The TP removal of the system is maintained above 95%,and which will fluctuate after the sidestream is terminated,but it can be recovered.The concentration of EPS will increase during sidestream,but the concentration of P stored in it may increase or decrease,which depended by sidestream operations—NaAc/Glc and C/N/P.When C/N/P=100/20/10,EPS_TP decreased by 45.84%;C/N/P=200/20/10,EPS_TP increased by 35.7%.When C/P?30,the operation mode of 1/4 cycle sidestream can effectively recover its P loss,improve its biological phosphorus uptake capacity,and maintain stable P release rate.The sidestream P recovery operation will impact the mainstream sludge microbial system,leading to changes in the level of biological colony structure and biodiversity.The relative abundance of Rhodocyclaceae,which plays a leading role in the biological phosphorus removal process,will decrease by72.12%⁸6.07%in the lateral flow process,which is obviously affected by sidestream process.After sidestream process is terminated,its proportion recovery depends on biological colony structure before sidestream and influent conditions.In this study,when the sludge influent conditions were C/N/P=100/20/10 and NaAc/Glc=3/1,the enrichment degree and recovery rate of Rhodocyclaceae were the highest.