Experimental Study On Treatment Of Landfill Leachate By Anaerobic Ammonia Oxidation

With the increase of municipal refuse production in China in recent years,Security Landfill as an economic and mature technology were increasingly used in the process of MSW disposal.However Landfill leachate which has tremendous endanger for environment will be produced in the process of sanitary landfill.Landfill leachate has the characteristics of high concentration of organic matter,imbalance of nutrient elements and high content of ammonia nitrogen,handling it has been a major problem all the time.The traditional treatment methods had some disadvantages,such as large power consumption and high processing cost,so it could not achieve an ideal result.The emergence of anaerobic ammonium oxidation technology provided a new way for treating landfill leachate.Its concise and efficient biological nitrogen removal pathway has attracted more and more attention in the industry,having high research value and broad application prospects.In the light of research hotspots about treatment of landfill leachate by anaerobic ammonium oxidation in recent years,under laboratory conditions,low carbon-nitrogen ratio high ammonium-nitrogen wastewater was uesd as object in this test,The test study on partial nitrosation process matching to anaerobic ammonium oxidation and anaerobic ammonium oxidation process respectively.Based on these studies,study on the nitrogen removal performance of partial nitrosification-anaerobic ammonium oxidation combined process was conducted.At last the actual landfill leachate was taken as the object of treatment,study on the denitrification performance of combination process,as to theoretical support for factory application of combination process.Experimental studies have shown that domestication and cultivation of nitrosation bacteria in the SBR reactor.Under the condition of intermittent aeration,nitrosation reactor was started-up successfully by 40 days commissioning test.By the way of increasing influent NH4+-N concentration,the stable running of nitrosation process under high ammonia nitrogen loads conditions was effectively achieved.The optimal process parameters of the nitrosation process was:temperature for around 30 ?,DO=1.Omg/L,aeration frequency for aeration 30min/stop aeration 30min,pH=7.5-8.0 and COD<150mg/L.Conducted at this condition,the NH4+-N removal rate NO2--N accumulation rate and COD removal rate were 93%90%and 82%respectively.For the influent NH4+-N concentration of 250mg/L,the preferable working sequence for partial nitrosation process was inflow(instant)-aeration(170min)-sedimentation(150min)-drainage(instant)-standby(160min).Using UASB reactor play experimental study for ANAMMOX,seeded with anaerobic digestion sludge from sewage treatment plant,ANAMMOX reactor was started-up successfully by 112 days commissioning test.During the stable running period,the removal rate of NH4+-N and NO2--N averages were 92.%and 94%respectively.Increasing the volume load of TN in the reactor through the method for increasing concentration of influent substrate,the load of TN was 0.232kg·m-3·d-1,TN removal rate was 87%.The optimal process parameters of anaerobic ammonia oxidation process were:HRT=24h,NO2--N/NH4+-N ratio for 1.1:1?1.5:1,temperature for around 30?,pH=8.0 and COD<150mg/L.By adding different kinds of organic matter in the system,the strongest inhibition to the activity of anaerobic ammonium oxidation bacteria was phenol,the weakest was glucose.When COD concentration is below 150mg/L,cooperative denitrification relations gradually formed between denitrifying bacteria and anaerobic ammonium oxidation bacteria in the system.Under preferable working condition with organic carbon,the average removal rate of NH4+-N NO2--N and TN reached 90%96%and 91%respectively,COD removal rate can be maintained at more than 85%.Through commissioning test ceaselessly for SBR nitrosation bacteria reactor and UASB anaerobic ammonia oxidation reactor in the first two stage,connectting the two reactors,study on composite system handled effect of low carbon-nitrogen ratio high ammonium-nitrogen wastewater for pollution factor respectively.The results showed that the average removal rates of NH4+-N TN and COD reached to 87.4%81.8%and 88.1%separately.For the treatment of landfill leachate,nitrogen removal effect of combined process is still relatively ideal,NH4+-N and TN removal rate can be stabilized at 87.4 and 81.8 separately,COD removal rate can be maintained at a high level,with an average of up to 88.1%,has achieved initial success.Partial nitrosification-anaerobic ammonium oxidation combined process can solve the problem of high operating cost and secondary pollution,the combined process can perform preferable nitrogen removal performance and reduce processing costs.So the economic benefit,social benefit and environmental benefit is great.