Carbon Source Sewage Simultaneous Nitrogen And Phosphorus Removal Process Applied Research

In recent years,with the improvement of living standards and industrial and economic development,municipal wastewater have also taken place in a corresponding change,in which N,P concentrations increased,making it more difficult to meet the traditional process of biological nitrogen and phosphorus removal.At the same time,most of Chinese large and medium-sized municipal wastewater treatment plant are low standard,and the majority of them have non-functional,such as nitrogen and phosphorus removal characteristics.On the other hand,the national laws,regulations and the policy proposed the stricter nitrogen phosphorus emission standard to the large and medium-sized municipal wastewater treatment plant.So it is important to study the nitrogen and phosphorus removal simultaneously process for low-carbon sources of sewage.This paper studies the development and change of nitrogen and phosphorus removal simultaneously process,explores the contradictions and problems of nitrogen and phosphorus removal simultaneously in A²/O process and summed up the improvement of A²/O process.We use the improved A-A²/O process of one sewage treatment plant as a simulation object and use actual sewage water of the other sewage treatment plant as a pilot. The actual water quality tests:CODcr 244-641 mg/L,BOD₅ 145-355 mg/L,NH₄⁺-N 40.5-87.6 mg/L,TN 50-105 mg/L,TP 2.5-9 mg/L,BOD₅/TN≈3,BOD₅/TP≈35.It is called the low-carbon sources of municipal wastewater because of the BOD₅/TN＜4.We,using 100%of the sludge and mixture return flow,mainly study the impacts of DO, SRT,Running processes and influent way in reaches.And have following conclusions:1.For nitrogen and phosphorus removal simultaneously process of the low-carbon sources sewage,a higher DO can resist the impact of influent ammonia load to ensure that the effluent is less than 1mg / L.However,activated sludge is easy for the aging and autolysis.Reasonable DO will help us to improve nitrogen removal rate.2.SRT(12＜SRT＜20d) does not affect the rate of carbon and ammonia removal,but a higher SRT can resist the impact of influent TN load.the lower SRT,the higher TP removal rates. 3.As the water less carbon(C/N of 3),there are carbon competition in the Nitrogen and phosphorus removal simultaneously process.In the same process parameters,influencing factors and water quality,the effluent TN of inverted A²/O process is better than it of A²/O process.Effluent TN concentrations is generally low-5mg/L than the A²/O process,but the effluent total phosphorus concentration than the A²/O process is slightly higher.4.In addition to carbon,the removal of ammonia is not affected by 1/2 influent way in the A²/O process and inverted A²/O process.For the multi-point water A²/O process,the effluent TN can reduce 5 mg/L,but it has little help to the TP removal.It has little effect on TN removal,reduces the total nitrogen 2-3 mg/L and resists the impact of influent TN load for using multi-point water inverted A²/O process.Also we found that the TP removal rate increases more,and the effluent TP is 0.5-1.0 mg/L.This study has the role of reference and guidance for conventional secondary biological treatment process of sewage treatment plant upgrade,and provides the appropriate basis for the same types of sewage treatment plants.