Study On The Upgrading Process Design Of A Wastewater Treatment Plant In Lu'an City,Anhui Province

In this paper,the actual operation technology of Chengbei sewage treatment plant in Lu'an City of Anhui Province is taken as the object of study.The biological process oxidation ditch is used to treat domestic sewage.The plant was built in 1999 with a design capacity of 80,000 tons/day.The effluent could meet “Sewage treatment plant pollutant discharge standards”(GB18918-2002)in the secondary standards.With the continuous expansion of urban areas,sewage pollutant concentration will be greatly improved,seriously affecting the existing process effluent quality,especially nitrogen and phosphorus pollutant indicators.Therefore,the plant is necessary to carry out technological upgrading.Through the investigation and analysis of the current situation of the city drainage and the operation of the sewage treatment plant,and the detection of the water and sewage indicators of the sewage plant,it is found that the plant can still run normally and the water quality index can meet the original design standard.The measured influent water quality is COD202 0.1mg / L,BOD92.4mg / L,SS127.67 mg / L,ammonia nitrogen 9.8mg / L,is still in the design of water quality range.According to the actual operation status of the water plant,this paper analyzes the existing problems in water quality,technology,equipment and operation,and puts forward the corresponding transformation plan.First,the original oxidation ditch process to transform,increase the multi-point water,increase the denitrification of the carbon source concentration,enhanced denitrification denitrification;the second is to increase the secondary treatment of deep effluent treatment process;third is to replace the original sewage plant There are some equipment to increase the depth of sludge integrated dewatering equipment;Fourth,upgrade the original control of the sewage plant software and hardware systems.After the biochemical treatment,deep treatment process,the depth of sludge dewatering process,disinfection technology,chemical phosphorus removal agent,deodorant process and other aspects of the preferred choice to determine the micro-flocculation + activated sand filter + UV disinfection process,integrated sludge Depth dewatering technology,poly aluminum chloride post-precipitation of the dosing method,reactive oxygen ion deodorization technology.After the transformation,the water quality of the effluent was statistically studiedand found that the removal efficiency of organic pollutants,nitrogen and phosphorus and suspended solids were increased to some extent,COD removal rate increased to 89%,BOD removal rate reached above 91%.The ammonia nitrogen content in the effluent was below 0.5 mg/L,the removal rate of total phosphorus was more than 90%,and the effluent SS concentration was stable at 5mg/L.The following indicators meet the A standard.