Experimental Research On Separating Organic Carbon From Municipal Wastewater By High-rate Activated Sludge System

In this study,Tianjin urban sewage was taken as the research object in the experimental study on the carbon separation of HRAS.The experiment mainly studies the characterization method of carbon separation of HRAS,the effect of HRAS on COD,TP and SS in urban sewage under different DO and SRT,the carbon separation,the characteristics of the sludge,the effect of pilot scale HRAS.The details are as follows:Firstly,the specific oxygen consumption rate and static adsorption rate of sludge were measured to establish the characterization method of biosorption performance.The results show that the linear goodness of the test curve is over 0.991,which quantifies the degree of biomineralized organic matter in sludge.The sludge reflects the rate and degree when sludge microorganisms adsorb and mineralize organic matter.The effects of different dissolved oxygen and sludge age time on the carbon separation of HRAS were investigated in the mall-scale HRAS reactor.The results show that it is favorable for HRAS when DO is 1.5 mg/L and SRT is 0.8 d.The removal rate of COD is 72%.The mineralization degree of organic matter is low.The operation state of carbon separation turn better.The removal rate of TP and SS is over 42% and 70%.The microbial diversity and community structure of HRAS were studied by highthroughput sequencing.The results show that the microbial diversity and the material abundance is small in HRAS.A few dominant bacteria reduce the uniformity.The nitrifying bacteria decrease.The species of sulfur bacteria with incomplete oxidation increase.Proteobacteria,Bacteroidetes and Firmicutes play biological functions.Finally,a pilot scale reaction platform of HRAS was built.After the start-up,pre operation and formal operation,COD is reduced to below 73 mg/L.The removal rate of COD is over 74.0%.The average removal rate of BOD is 79.5%.The removal efficiency of other pollutants is good.The sludge yield of HRAS system is greatly improved,and the effect of carbon separation is significant.Figure 31;Table 9;Reference 80...