Selection And Application Evaluation Of Improvementtechnologies Of Domestic Sewage Treatment Plant In Small Towns

In view of the situation and demand of water environment treatment,China’s urban sewage discharge standards had undergone a rapid development process from comprehensive discharge standards to industrial discharge standards,from national standards to local standards.Overall,the pollutant control indicators were increasing and the requirements were constantly stringent.This process of gradual improvement of requirements was driven by standards,which also promoted the rapid development of sewage treatment facilities in China.Sewage treatment plants had become the main force of total pollution reduction in China in the past ten years.This study found that the effluent quality of the 6 town sewage treatment plants can only meet the“Emission Standards for Pollutants in Urban Sewage Treatment Plants”after the background investigation of the sewage treatment plants in the six towns of A County,the investigation of the status quo of sewage pipes and the site survey.The first-class B standard does not meet the first-class A standard that meets the requirements of the county.Through site survey and water quality testing,it is found that both B and D towns are aerated biological filters,C and G towns are oxidation ditch,and E and F towns are A²/O biological pools;TN,NH3-N,TP,BOD₅ in influent water quality The content of CODcr is higher;the ammonia nitrogen and TN in the treated effluent can not meet the first-class A standard,indicating that the denitrification capacity of the sewage treatment plant before transformation is insufficient.The C/N ratio in the sewage of each town sewage treatment plant is less than 4except for F town,indicating that the biological nitrogen removal carbon source is insufficient.The process evaluation and water quality analysis of the sewage treatment plant in 6towns of A County after the transformation,and the comparative analysis from the technical qualitative and quantitative perspectives.It was found that the biological aerated filter+BAF biological treatment process was reasonable after upgrading B and D towns;the combined oxidation ditch and BAF biological treatment process was adopted after upgrading C,E,F and G towns.It is reasonable.Through the water quality test of the sewage treatment plants in6 towns of A County,it was found that the effluent quality of all sewage treatment plants after upgrading and upgrading meets the Grade A standard of the“Emission Standards for Pollutants in Urban Wastewater Treatment Plants”.It shows that the process improvement of each treatment plant is feasible and the engineering transformation is successful.This provides an effective reference for the upgrading of urban sewage treatment plants in China.