Experimental Study On Advanced Treatment Of Domestic Sewage By Short-cut Nitrification-ANAMMOX

The water nitrogen pollution of our country becomes more and more serious.The traditional denitrification process has a great deal of power consumption and complicated technological process.It needs additional organic carbon source and alkalinity.It also produce large amount of sludge,which is easy to cause secondary pollution.This process costs a lot and has a series of shortcomings.The discovery of ANAMMOX technology provides a simple and economical biological nitrogen removal pathway for wastewater treatment,so it attracts great attention of researcher and has a very high research value.Aiming at the problems and the research hotspots of ANAMMOX in recent years,based on wastewater of low NH4+-N,this paper studied the short-cut nitrification and ANAMMOX process to provide the theoretical basis and application technology for the combined process with low ammonia nitrogen wastewater under the laboratory condition.Firstly,two sets of the same short-cut nitrification devices were set up by continuous aeration and intermittent aeration and inoculated activated sludge with good nitrification performance.After a month of running and debugging,The short-cut nitrification devices were set up successfully.In addition,the influence factors(such as temperature,pH,DO concentration)of short-cut nitrification process were further studied.The results showed that:in the short-cut nitrification start-up stage,the intermittent aeration mode should be adopted,and the aeration rate of 0.3?0.4L·min-1,temperature of 30 ± 1 ? and pH 7.8?8.2 could be adjusted.When the temperature is 25?35 ? and the pH is between 7.5 and 8.5,nitrification is suitable for short-cut nitrification.Then,three sets of the same ANAMMOX reaction device were set up,and the inner packings were elastic filler,volcanic rock and ceramsite respectively.After about 150d of operation and debugging,three devices were started successfully,and stable operation.The denitrification performance of the ANAMMOX process can be improved by controlling the influent matrix concentration and HRT after the stable operation of plants.The TN removal rate and the volume loading average value can reach 85.25%and 0.463kg·m-3 d-1,respectively.In addition,the optimum process parameters of ANAMMOX were HRT= 24h,temperature about 30 ?,pH=8.0,and aeration rate of 0.3?0.4L/min through the study on influencing factors of ANAMMOX reaction.Finally,the first step is to control the reaction conditions of short-cut nitrification,so that the effluent can be matched ANAMMOX reaction.After that,the short-cut nitrification devices were connected with ANAMMOX devices,then devoted them into the advanced of the application of sewage treatment.In the two process docking process,should be selected short-range nitrification stage of effluent NO2--N/NH4+-N between 1.15?1.35,as the effluent of ANAMMOX.Because the volume loading of the short-term nitrification stage effluent in this experiment is low,so the volume loading can be increased by increasing the filtration rate to achieve docking of two process quickly.After 60 days of operation and debugging,the removal rates of TN and CODcr in the combined process were good,which were 87%and 89%.