Study On Domestic Wastewater Efficiency And Sludge Characteristics By Micro-Pressure Inner-Loop Bioreactor

As a new type of sewage treatment technology,the micro-pressure inner-loop multi-biological urban sewage treatment technology differed from the traditional sewage treatment process in structure and aeration mode,and formed a circulating flow state through a single side aeration device,Area to achieve the simultaneous effect of nitrogen and phosphorus removal.This experiment is based on the micro-pressure internal circulation reactor for the experimental study of the actual urban sewage,the set of test device to deal with the water volume of 290 m3/d,reached the scale of pilot test,the specific test process,including the start-up,commissioning and stable operation,And the removal of pollutants and sludge characteristics of the analysis,according to the results of the four months of operation to get the following main conclusions:?1?The experiment was carried out with sludge directly from the sewage plant,the influent was 12.10m3/h,the reflux ratio was 100%,the concentration of MLSS was about 4000mg/L,the ratio of gas to water was 3.5:1,HRT was 8h,The average removal efficiencies of COD,NH₄⁺-N,TP and SS were 82%,97%,88% and 78%,respectively.which achieved the expected treatment effect.Successful commissioning of the test system.?2?The process parameters were MLSS=4500⁵000mg/L,wastewater amount Q = 10m3/h,gas/water ratio=4.25:1,HRT=9.6h,reflux ratio R=100%,SRT=24d,DO concentration above 1.5 mg/L,and DO concentration between 0 and 0.1mg/L.In this condition,the COD,NH₄⁺-N,TN,TP and SS concentrations in the effluent of the pilot plant were 25mg/L,4.4mg/L,14.7mg/L,0.49mg/L and 30mg/L,Meet the "urban sewage treatment plant pollutant discharge standards"?GB18918-2002?of the emission standards,Among them COD,NH₄⁺-N,TN,TP have reached the level of A standard.?3?the pilot system reflects the high removal of organic matter and the ability to resist strong characteristics.Due to the low influent COD concentration,the microbial flora in the pilot plant was kept at a low organic loading state,and the activated sludge in this state reduced the COD concentration of the effluent to below 30 mg/L and had high organic removal ability.The removal rate of SS and COD in the pilot plant can reach more than 80%,indicating that the device has a strong anti-shock load capacity on the influent SS and COD concentration changes.but the running The process of changes in external factors will affect the effect of nitrogen and phosphorus removal.?4?When the water temperature of the pilot plant was above 12.5?,the extracellular polymer,SVI,dehydrogenase activity and specific oxygen consumption rate of the sludge can show that the activated sludge has a strong metabolic capacity and Better biological activity.With the decrease of water temperature from 12.5 ?,the rising trend of sludge SVI gradually slowed down,the extracellular polymer showed the trend of decreasing first,then rising again and then rising again,the decreasing trend of dehydrogenase activity tended to be flat,The rate of oxygen was in the descending speed to accelerate the state,indicating that the cooling effect on the microbial activity is strong.And the activity of sludge increased when the water temperature dropped from 10? to 9?.