Study On Operating Conditions And Improving Process Of ANAMMOX-SBR

In recent years,although our country sewage treatment has increased a lot,the nitrogen pollution is still increasingly serious and it has brought great harm to both the ecological environment of water and the drinking water safety.Because of the long process,oxygen consumption,and external carbon source requirements and other characteristics,traditional biological nitrogen removal process always need high investment and running costs.So,efficient,rational and economic process of wastewater treatment process is needed to solve these problems.ANAMMOX process is now known as the most simple and economic method and it has ow oxygen demand,low cost and no additional carbon source is needed during this process.In this case,it will surely play an important role in future.In this issue,operating conditions and optimizing process of ANAMMOX-SBR were studied to explore the application value of this process.In this experiment,SBR were operated parallelly to treat artificial simulated sewage.Impact factors of anaerobic ammonium oxidation including HRT?influent pH value?DO?temperature?concentration of ammonia nitrogen and NO2--N/NH4+-N ratio were studied in the paper.Optimal operating conditions of the reactor have been concluded:HRT is 12h,pH is 7.5,DO<0.03mg/L,temperature is 32 ?,concentration of NH4+-N is 300 mg/L,concentration of NO2--N is 380 mg/L,ammonia nitrogen and nitrite nitrogen substrate ratio is around 1:1.3 and at these situation,both the removal rates can reach to 98%.Granulated sludge under the optimal conditions can be observed obviously in SEM and has a good appearance.In addition,through the continuous pH and ORP record of effluent under different conditions,we can conclude the feasibility of application of the two indicators to measure the performance of the reactor.The sludge which is under a steady state of ANAMMOX reactor is taken to do the batch experiments and the effect of chemical flocculation agents and MBFA9 on sludge characteristics and sedimentation is also studied to find the possible method to avoid sludge loss.This paper also explores the flocculant's influence in the nitrogen removal performance.Results showed that both the two flocculants have effect on the anaerobic growing conditions of ammonia-oxidizing bacteria and nitrogen removal efficiency,and in comparison,MBFA9 have less effect on the system than chemical flocculant.So this method can be thought feasible.Sludge at good condition is added to both non-woven membrane reactor and simple SBR.By comparing the treatment effect and characteristics of activated sludge in the reactor,the effect of non-woven membrane is studied.Under the steady-state,the NO2--N and NH4+-N removal rate of the two reactors can reach to 80%.But when it comes to the load test,SBR reactor shows a better stability.Sludge under good state in two reactors was observed under the scanning electron microscope and the one taken from the non-woven reactors shows more kinds of bacteria than the other.The results show that the reactor without non-woven is better for anaerobic ammonium oxidation.