Analysis Of Water Quality Characteristics Along The A~2O Process In A Municipal Wastewater Treatment Plant And Research On The Plan For Improving Quality And Efficiency

With the basic achievement of the goal of centralized treatment of urban sewage in my coun-try and the successive release and implementation of stricter local drainage standards in various regions,it indicates that the improvement of the discharge standards of urban sewage treatment plants in my country will be an inevitable trend.This paper takes the first-phase A2O process of a sewage plant in Xi’an as the research object to conduct process optimization research to improve the effluent quality of the process and reduce energy consumption.This article first uses conventional indicators,three-dimensional fluorescence data and LC-OCD to analyze the wastewater quality of the process along the way.It is found that there are carbon sources intercepted by the primary sedimentation tank,the return sludge carries excessive nitrate nitrogen,and the return mixed liquid carries too much dissolved oxygen and insufficient carbon source in the anoxic tank.In response to the above problems,the quality improvement and efficiency plan proposed in this paper cancels the primary sedimentation tank in the original process,uses the anaerobic tank to enter the water at points to solve the problem of insufficient carbon source in the anoxic tank,and replaces the aerobic tank of the original process with the fourth The corridor is transformed into a non-aerated zone and the second aerobic tank.The mixed liquid is refluxed at the end of the non-aerated zone,and suspended fillers are added to the anaerobic tank,anoxic tank and the first aerobic tank to increase the abundance of microorgan-isms,add a sludge anoxic tank to reduce the nitrate nitrogen in the return sludge.Based on the process to improve quality and efficiency,a generalized model of the optimized process was established on the GPS-X simulation platform and the model was calibrated.Deter-mine the operating parameters of the process through single factor simulation,and finally select the best DO,R,r,segmented water inlet ratio,filler filling ratio,non-aeration zone and second aerobic tank volume ratio,and sludge anoxic tank retention time.The parameter values were 2.4 mg/L,160%,50%,20%,25%,6:4,30 min.The 89-day dynamic data simulation results show that BOD5,NH3-N,and TN in the effluent quality indicators of the optimized process stably meet the A standard in the "Shaanxi Province Yellow River Comprehensive Wastewater Discharge Standard"(DB61/224-2018).The effluent COD is mainly contributed by soluble inert organic matter,which cannot be treated by biological reactions,and should be supplemented with ad-vanced treatment in practical applications.Under the condition of no chemical phosphorus re-moval,the average removal rate of TP reaches 95.6%.Only when the influent TP load is high,there will be a small amount of excess.At the same time,the total energy consumption is reduced by 13.0%compared with the original process.Therefore,the process quality and efficiency im-provement program proposed in this paper strengthens the process’s nitrogen and phosphorus removal effect and reduces energy consumption,achieves the purpose of quality and efficiency improvement,and can provide reference and technical reference for the quality and efficiency improvement of the same type of process.