Study On The Upgrapding Technology Of Urban WWTP Based On Enhanced A~2O Technology

With the rapid development of urbanization, the continuous increase of sewage discharge quantity, water resources are polluted seriously resulting into the water crisis in terms of water quality. The direct way resolves the problem is make sewage become a kind of stability water resource by raising the treatment quantity of wastewater, increasing the treatment efficiency of sewage treatment plant. For meet the requirements of sewage as city’s second water resource, Domestic most of the early construction of WWTP face upgrading and reconstruction problems.Nowadays, the majority of the WWTPs in our country are using activated sludge process to dispose wasterwater. Activated sludge process including ordinary active sludge method, oxidation ditch and SBR, AO, A2O, UCT and so on, There are more then 50% of our WWTPs using A2O process. This process combines the anaerobic/ aerobic phosphorus removal process with anoxic/ aerobic nitrogen removal system, which can remove the organics, phosphorus and nitrogen in the water simultaneously. Nitrobacteria and denitrifying bacteria are in the process of the whole cycle is in a state of activation, dormancy and vivification alternately. The most of the northern area’s low temperature period up to more than six months. Because the low temperature will cause the bioactivity suppressed, it is necessary to increase the temperature correction factor. Although the tank was increased a lot, denitrification effect is unsatisfactory. This topic innovatively proposed "sewage treatment by activated sludge process stage to strengthen technology". From increasing biomass and improve Microbial living environment.Based on parallel test found enhanced A2O systems’average removal rate of CODcr、NH3-N、TN、TP is 85%、70%、62.6%@87.7%。Compared with the traditional A2O process, It’Increased to 14%,14.9%,10.3%,12.9%.Back flow of the liquid in denitrifying reduced from 400% to 200%, energy-saving effect is remarkable.Dynamics test results showed, the relationship dynamics equation of organic degradation can be used to calculate the organic matter degradation time, the nitration reaction time can use the relationship dynamics formula of nitration reaction time to make sure. The relationship dynamics formula of denitrification reaction time can be used to know the volume of systematic anoxia pond.The results of part can be used as the basis for guiding the engineering practiceFor a county of jilin province 14000 m3/d of A2O wastewater treatment plant, Based on parallel test found that compared with the traditional A2O process, enhanced A2O process, the CODcr, ammonia nitrogen, TN and TP removal efficiency than the original system value reached 10.1%,11.7%,13.1% and 12.7% respectively. The process has the advantages of easy to operate, conserve land, simple operation, applicable to the mentioned standard transformation of the activated sludge process of sewage treatment plant.This research adapted our national continuous development policy of setting up resource and saving water, especially it build a new road for comprehensive management of our city and for using recreating water to resume landscape, therefore it should have applying prospect, and promote increasingly development of our water disposal course.