Study On Upgrading Process Of A Sewage Treatment Plant In Northwest China

With the Water Pollution Prevention and Control Action Plan issued by the state council and provinces and cities,China’s environmental governance requirements for key river basins have been strengthened,For the first time,the State Environmental Protection Administration has issued a circular on strict implementation of pollutant discharge standards for urban sewage treatment plants,“in order to prevent eutrophication of water bodies,when effluent from urban sewage treatment plants is discharged into the closed or semi-closed water areas,such as lakes and reservoirs,determined by the state and the province,the standard A shall be applied”.Most of China’s sewage treatment plants were built in the last century,when the standards needed to meet are very low,can not adapt to the current environmental development,so most of the current sewage treatment plants are in urgent need of upgrading.This paper makes a research on the upgrading project of a sewage treatment plant in northwest China,Through the status quo of the operation of the plant to investigate,This bid upgrading project is based on the designed water volume of the first phase of the sewage plant,combined with the monitoring results of the water quality in and out of the current situation of the plant,and considering that the plant covers a relatively tight area,mainly through the biochemical system,sludge system reform and secondary treatment after the addition of depth treatment system,so as to meet the effluent quality standards.NH₄⁺-N、TN、SS、TP are the key treatment projects in the upgrading project of a sewage treatment plant in northwest China,among them,NH₄⁺-N and TN can be removed mainly through the rational allocation,fine management and accurate control of functional areas in the biochemical system;low carbon nitrogen ratio is a common problem in most sewage treatment plants in China,chemical methods alone are difficult to remove large amounts of nitrogen,so phosphorus-sacrificing biological methods are an option for most wastewater treatment plants.Part of the transformation process of the engineering biochemical treatment is"from aeration mode to surface aeration carussel oxidation ditch to blast aeration A²/O",by adding suspended filler in aerobic zone,the microbial quantity of the system was improved,so as to enhance the nitrification capacity and denitrification capacity of the whole system,and a reasonable carbon source was added to the anoxic pool to change the situation of low inlet carbon and nitrogen.This project adopts the deep treatment process of"efficient sedimentation tank+v-type filter tank",supplemented by the addition of chemical agents,not only makes the TP in the effluent reach the standard,but also further removes the concentration of COD,BOD₅,TN and other pollutants in the sewage,so as to ensure the effluent quality meets the relevant standards.