Research And Application Of A/O Step-Feed Domestic Sewage Treatment Process

This paper mainly solves the problem of insufficient sewage treatment capacity in the main urban area of Karamay City.The second sewage treatment plant of Karamay City was expanded and reconstructed to achieve the total treatment water volume of 150000 m3/d and the effluent quality meeting the international class A discharge standard.According to the requirements of pollutant removal rate,the advantages and disadvantages of four secondary treatment processes,A/O Step-Feed domestic sewage treatment process,biological aerated filter,A2 O biological pool and MBR pool,are compared and selected.The applicability of liquid chlorine,chlorine dioxide,ozone,ultraviolet and potassium bisulfate composite bactericide is analyzed,and "multi-stage and multi-stage Ao biological pool" is finally selected The main treatment process of " A/O Step-Feed domestic sewage treatment process + denitrification deep bed filter + single potassium bisulfate disinfection".Through theoretical analysis,6 main characteristics of A/O Step-Feed domestic sewage treatment process are calculated and analyzed.The main results are as follows: A/O Step-Feed domestic sewage treatment process has high average sludge concentration,which is beneficial to improving the effect of p Hosp Horus and nitrogen removal.It is suitable for biological treatment of municipal wastewater with insufficient carbon source.At the same time,the process has obvious advantages of flexible adjustment and control in denitrification.There is no need for backflow of digestive solution,saving equipment investment and energy consumption of later sewage plant operation.At the same sludge age,the capacity of the multi-stage Ao process is only 75% of that of the conventional single-stage A/O process and A2 O process.A/O Step-Feed domestic sewage treatment process is conducive to the realization of short cut nitrification and denitrification.The process has the advantages of small land occupation,low operation cost,flexible control and efficient denitrification.Through the establishment of CFD sedimentation model and ASM2 D activated sludge model,the main design parameters of A/O Step-Feed domestic sewage treatment process are simulated and calculated by West software,and the main design and operation parameters are analyzed: reaction order n,the optimal residence time of each stage A/O biological section,water distribution ratio at all levels,the impact of changes in do of dissolved oxygen on the effluent effect of biological pool,and the design of process treatment unit is carried out Calculation,general layout and flow chart design.In the later stage of the commissioning and operation of the sewage plant,through the comparison of the water quality data of the sewage plant in May,August and November,the analysis of the removal rate is carried out,and the mutual verification with the simulation calculation results shows that the design and operation parameters in the analysis results are reasonable and effective.The final design of the sewage plant tail water discharge meets the requirements of the national level a discharge standard.