Selection Design And Commisoning Of The Upgrade And Transformation Process For The Third Sewage Treatment In Weihai

In recent years,with the rapid economic and social development in Weihai,more and more attention has been paid to sewage treatment.The discharge of sewage has increased rapidly,resulting in the pollution of urban river courses,but the original Sewage Treatment was designed to comply with the First Class B emission standard.As a result,supporting sewer lines and Sewage Treatment are in urgent need of construction.Based on the field investigation in Weihai,this paper puts forward the necessity of the third Sewage Treatment extension and technological transformation project in Weihai,and analyzes the present situation of urban drainage:The average SS was 174.2 mg/L,the average COD was 340.13 mg/L,and the average ammonia nitrogen was 25.12 mg/L,TP w as 8.57 mg/L,BOD₅was 281.56 mg/L.Through the water quality monitoring of Weihai No.3 sewage treatment plant,this paper finds out the variation law of organic matter in Weihai sewage by sampling analysis,which provides an important basis for process selection.Through comprehensive comparison and selection of technology,economy and operation maintenance,LHPs,a patented technology of von roll BHU company in Germany,has been found to have excellent performance in treating SS and nitrogen and phosphorus with high efficiency inclined tube sedimentation tank+biological aerated filter.The results show that the average SS,COD,NH₄⁺-N,TP and BOD₅ of the effluent are 24 mg/L,19 mg/L,3.6 mg/L,0.33mg/L and 12.7 mg/L respectively.This result indicates that the LHPS high-efficiency sedimentation tank+BAF process can meet the first-class standard of effluent water quality in the area of great environmental change in Weihai.Therefore,it is recommended as the first choice for the third Sewage Treatment upgrading process in Weihai.The effluent SS,nitrogen and phosphorus of the original treatment process of the third Sewage Treatment in Weihai Bay exceeded the standard.According to the pilot-scale test,LHPS+biofilter can improve the treatment efficie ncy of the corresponding index.Through planning,design and calculation of the unit treatment structure,the upgrade and reconstruction of the Sewage Treatment has been completed,and through the operation and debugging,the average SS of the effluent water quality was 24 mg/L,the average COD was 12 mg/L,and the average ammonia nitrogen was 4.7 mg/L,the TP average value is 0.47 mg/L,the BOD₅ average value is 3.8 mg/L,which meets the First Class A emission standard.After upgrading and transformation,the water treated by the upgraded Sewage Treatment reaches 80,000 t/d.As for cost,the total construction cost is about 114.67 million yuan,and the sewage treatment cost per ton is 0.4225yuan/t.