Study Of Influencing Factors On Denitrification Performance Of Anaerobic Ammonia Oxidizing Bacteria

In order to meet the requirements of petroleum refining process,all kinds of catalysts are often needed.The production process of catalyst will produce a large amount of catalyst production wastewater,which is mainly characterized by high ammonium and low C/N ratio.The traditional biological denitrification technology is used to treat it,with the addition of carbon source,high treatment cost and unstable operation,which can not meet the latest sewage discharge standards.In recent years,the emergence of anaerobic ammonia oxidizing（anammox）has brought a new direction for wastewater denitrification process.There are many problems in practical application,due to anammox bacteria are sensitive to the living environment.In this paper,the tolerance and recovery of anammox bacteria to various factors were investigated by exploring the effects of different water quality factors（temperature,salinity,organic matters and substrate concentration）on the denitrification performance of anammox bioreactor.The harm of water quality factors on anammox bacteria and the relationship between environmental factors and anammox bacteria community structure was analyzed based o n the insight of microbial community structure.An effective method formed to guide the activity recovery of anammox bacteria and the harm early warning technology of bacteria to prevent the cliff decline of denitrification performance of anammox.The best denitrification performance was occurred at medium temperature,with the reduction of ammonium and nitrite were more than 90%.Anammox bacteria（candidatus brocadia）were the dominant bacteria and account for 38.77%.Under the high temperature（50°C）and high salt（5000 mg/L）condition,anammox bacteria showed serious discomfort and the denitrification performance decreased sharply,and the recovery periods were as long as 40 d and 30 d,respectively.The relative content of（candidatus brocadia）of anammox bacteria decreased sharply,and microorganism dead,even broken down by bacteria for anaerobic digestion process,which can be proved by the increased abundance of anaerolineaceae and limnobacter.Room temperature（20°C）and low salt（3000 mg/L）have a little effect on the denitrification performance of the bioreactor,the substrate removal rate was reduced to 55%and 50%respectively,but the anammox bacteria show a certain adaptability,and the species abundance increases slightly.With the addition of organic matter,the denitrification performance of the bioreactor gradually decreased,the anammox was no longer the main reaction,the relative content of nitrifying bacteria and denitrifying bacteria increased,and the activity of anammox bacteria was suppressed.however,after the removal of organic matter in the influent,the bioreactor returned to stable operation within 9 d,and the removal rate of ammonium and nitrite was more than 90%.High substrate concentration had little influence on anammox bacteria,on the contrary,the denitrification rate of bioreactor increased at high substrate concentration,and the relative content of anammox bacteria（candidatus kuenenia）in the bioreactor increased.Therefore,for the operation of the anammox bioreactor,the influence of temperature and salt should be pretreated to the acceptable range of anammox bacteria,which is suitable for the treatment of low-COD,and high-NH₄⁺wastewater.During operation,attention should be paid to the tolerance and recovery of anaerobic ammonia oxidation bacteria to maintain the stable operation of the bioreactor.