Study On The Mechanism Of Bioaugmentation And Long Term Maintenance Of Microbial Communities In Urban Wastewater Treatment Under Low Temperature Conditions

Urban sewage,industrial wastewater and agricultural wastewater contain a large number of nitrogen and phosphorus elements,resulting in serious water pollution.Biological treatment method for nitrogen and phosphorus removal is a widely used nitrogen and phosphorus treatment method in sewage treatment plants.However,the low average winter water temperature in northern China will affect the effectiveness of biological nitrogen and phosphorus removal.Bioaugmentation technology is a method that is very suitable for improving the biological treatment efficiency of wastewater under low temperature conditions.It has the advantages of convenient operation,obvious treatment effect,and no need to change the original operating procedures.This paper concentrates an aerobic denitrification bacteria that produces PHA,and uses it as a autotroph intensifier in the ambient temperature bioaugmentation test.It compares with the heterotrophic bioaugmentation bacteria purchased in the market,and explores the impact of different bacterial agents on the biological treatment effect of sewage under ambient temperature conditions.Furthermore,biological augmentation experiments were conducted under low temperature conditions to explore the effects of different bacterial agents and dosage on the biological treatment efficiency of wastewater under low temperature conditions.In this paper,the aerobic denitrifying flora enriched by the Feast/Famine mode to produce PHA was studied to provide a sludge source for subsequent room temperature autotrophic biointensification.Compared with the effects of carbon-nitrogen separation and carbon-nitrogen coupling on the enrichment effect of aerobic denitrifying bacteria,through the monitoring of the water quality change,operation stability and PHA production capacity of the reactor,it was found that the microbial colonies enriched by the influent mode of carbon-nitrogen separation were stronger than those enriched by the carbon-nitrogen coupled influent mode,whether it was denitrification capacity,the operational stability of the reaction system or the PHA production capacity.In this paper,the autotrophic biofortification and heterotrophic enhancement effects of microorganisms were compared under normal temperature conditions,among which autotrophic biofortifiers were aerobic denitrifying bacteria enriched by carbon and nitrogen separation and influent water,because they could accumulate and synthesize PHA when the carbon source was abundant,so as to decompose and utilize cells when the carbon source was insufficient,so as to achieve the autotrophic enhancement effect.Heterotrophic biofortified bacteria use purchased microbial lyophilized fungi,which are nitrifying agents,denitrifying agents and compound agents mixed with the two.The strengthening effect of different biological agents and the dosage of different biological agents on the sewage treatment effect under normal temperature conditions were explored.In this paper,a bioenhancement test was carried out under low temperature conditions,and the strengthening effects of three heterotrophic bioreinforcement agents of microorganisms were compared,namely,nitrifying agents,denitrifying agents and compound agents were added for bioenhancement,and the low-temperature strengthening effect and strengthening maintenance time of different biological agents were explored,and it was concluded that nitrifying agents need to be added regularly every 20 days,and denitrifying agents need to be added regularly every 15 days,and the compound bacteria can be maintained for a long time.The effects of different dosage amounts on the effect of sewage treatment were compared,and it was concluded that when the dosage of nitrifying bacteria,denitrifying bacteria and compound bacteria was 5‰,1‰ and 1‰,it could not only achieve better effluent effect,but also save the cost of fungicides.