Research On The Domestic Sewage Treatment By The Double Mud Method And Multi-point Influent OAO Process

With the rapid development of social economy,the requirements of the water environment are getting higher and higher,the sewage discharge standards are becoming more and more stringent.Therefore,the research of high efficient decarbonization and nitrogen and phosphorus removal system is of great significance to the development of nitrogen and phosphorus removal process,and it has a broad application prospect.This experiment adopts double mud method and multi point influent OAO process,it is study on the pollutants removal during the cultivation of sludge acclimation,as well as,the effect of different influent flow ratio and dissolved oxygen of the Aerobic pool on the performance of the system.And the optimum influent flow ratio and dissolved oxygen concentration are obtained.Meanwhile,the change of microbial community in this system was studied under the optimum conditions.The main conclusions are as follows:(1)During the period of domestication,with the development of sludge culture,the removal rate of pollutants showed an upward trend.During the late period of domestication of inoculated sludge(twelfth days later),the removal rate of COD,ammonia nitrogen,TN and TP can reach more than 95%,more than 93%,more than52%,more than 55%,and the removal effect is good.(2)In the case of the influent flow distribution ratios are 1: 1,1.5: 1,2: 1,the system has good removal efficiency and stable removal rate for COD and ammonia nitrogen,and the effluent could meet the requirements of " Urban sewage treatment plant pollutant discharge standards "(GB18918-2002)of the first A standard.The change of the influent flow rate has no obvious influence on the removal of COD and ammonia nitrogen.The influence of different influent flow ratio on the removal efficiency of TN are greater.With the increase of influent flow ratio,the average removal of TN increases to more than 55%,and then it has a slight decline.When Q1/Q2=1.5:1,The average removal rate of TN was 55.94%,and the removal rate of TN was the highest.The influence of different influent flow ratio on the removal efficiency of TP was also obvious,and the fluctuation of TP removal rate is relatively large.With the increase of influent flow ratio,the average removal rate of TP firstly increased and then decreased.When Q1 / Q2 = 1.5: 1,TP removal rate is highest.Overall,when Q1 / Q2 = 1.5: 1,COD,ammonia nitrogen,TN,TP can achieve a higher removal rate.(3)Under the low dissolved oxygen condition,the removal rate of COD and ammonia nitrogen can reach more than 90%,and the effect on removal is very small.The effluent could meet the requirements of " Urban sewage treatment plant pollutant discharge standards "(GB18918-2002)of the first A standard.With the increase of dissolved oxygen,the removal rate of TN decreased.When dissolved oxygen is 1.0mg/L,the removal efficiency of TN is relatively good,and the average removal rate of TN was 54.08%.The removal rate of TP system fluctuates greatly.When dissolved oxygen is1.0mg/L,the average removal rate of TP was 47.94%.When dissolved oxygen was1.3mg/L,the average removal rate of TP was 41.80%.On the whole,the removal rate of TP was higher when dissolved oxygen was 1.0mg/L.Overall,when the dissolved oxygen is 1.0mg/L,COD,ammonia,TN,TP were able to achieve a higher removal rate.The actual operation can be appropriate to reduce the amount of aeration,and the Double mud method and Multi-point Influent OAO Process can achieve high efficiency nitrogen and phosphorus removal under the low energy consumption.(4)In the study,16 sDNA high throughput sequencing technique was used.It compared the microbial communities of the inoculated sludge with the microbial communities of the system of the Double mud method and Multi-point Influent OAO Process.The result shows: Proteobacteria and Bacteroides are predominant bacteria,especially the Betaproteobacteria and Gammaproteobacteria of Proteobacteria.