Study On The Treatment Of Wastewater From Refuse Transfer Station By A~2/O-MBR Process

Refuse transfer station is an important part of municipal waste collection andtreatment, the large amounts of pollutants such as leachate, kitchen waste and sewage inthe wastewater from refuse transfer station potentially threat the surrounding environmentand people’s health,and we must enable it to discharge into the municipal sewer network.The content of this study is to combine traditional biological denitrification andphosphorus removal process (A2/O) with membrane biological technology (MBR), whichformed A2/O-MBR process, applying this process to the treatment of wastewater fromrefuse transfer station, the main content and the results of the research are as follows:Firstly, by controlling the hydraulic retention time (HRT), dissolved oxygen (DO),sludge reflux ratio and other factors, A2/O-MBR process was studied to find out theoptimal operating parameters. The results showed that, the optimal operating parameterswas: HRT=12h, DO=2.0~4.0(mg/L), external reflux ratio was200%, internal refluxratio was200%. The average COD, NH3-N, TN, and TP reached4.1mg/L,1.2mg/L,9.4mg/L, and0.3mg/L respectively. The average removal efficiency reached97.7%,95.9%,77.3%, and91.0%respectively. The water quality was better than miscellaneous domesticwater quality standard (GB/T18920-2002).Secondly, the study explored the effect of A2/O-MBR to treat the simulatedwastewater from refuse transfer station, and analyzed the influencing factors. The resultsshowed that,(1) during the experiment, different dilution had little influence on theremoval of COD and TP. With increasing of the load, the removal of NH3-N and TNdecreased, but latter in the experiment, the removal of NH3-N gradually increased to89.25%, it can be considered that the system had good effect on the removal of NH3-N;(2)by adjusting the C/N and the intenal reflux ratio, it showed that the removal efficiency ofTN increased with the increase of intenal reflux ratio, it reached the maximum47.6%when the reflux ratio was400%. The removal efficiency of TN also increased with theincrease of C/N in the simulated wastewater, it reached the maximum71.7%when theC/N was10.2;(3) the water quality of COD and TP achieved the denmand of pollutionstandards of landfill municipal waste (GB l6889-2008). When the internal reflux ratio was 400%and C/N8, the quality of NH3-N and TN was slightly higher than the demand thatthe standard requires, but was able to dischargre into the municipal pipe network.This topic explored and researched the feasibility of the treatment of waste waterfrom refuse transfer station by A2/O-MBR process, which provided an energy-efficientway to treat the wastewater. Therefore, it had an important reference value to deal with thewastewater from refuse transfer station, which is short of land.