Biofilm Anaerobic Ammonia Oxidation Treatment In High Concentration Of Nitrogen Wastewater

Anaerobic ammonium oxidation(ANAMMOX)biological denitrification process has become a research hotspot for scholars at home and abroad because of its remarkable advantages of saving oxygen consumption,low sludge yield and high matrix removal rate.However,in the activated sludge method,the anaerobic ammonium oxidizing bacteria are difficult to intercept,and are easily lost,and the shortcomings of the influent water quality are difficult to achieve in large-scale engineering applications.To this end,this experiment used an upflow anaerobic biofilm reactor to investigate the effect of biofilm optimal reaction matrix ratio,matrix concentration,impact load and other factors on the efficiency of anaerobic ammonium oxidation process.In this study,a stable anammox treatment system was established in an anaerobic biofilm reactor.Then,the effect of substrate ratio on the denitrification efficiency of anammox biofilm was investigated by changing the inlet matrix ratio.On this basis,the nitrogen concentration of inlet matrix was increased to investigate the influence of different inlet matrix concentrations on the nitrogen removal effect of anammox biofilm method.Then,the impact load test of biofilm was carried out.Microscopical observation and macro-genome sequencing were used to observe the structure and morphology of macroscopical bacterial micelles and biofilm and analyze the distribution characteristics of bacterial species.Obtain the following conclusions:(1)Experiment with the influent matrix ratio(NH4+-N:NO2--N)of 1:1.32,1:1.20,1:1.108,respectively,by comparing the comprehensive denitrification performance of two biofilm systems It was investigated that the anaerobic ammonium oxidation reaction of the two biofilm systems was the best when the matrix ratio was 1:1.20.At this time,the average removal rates of ammonia nitrogen and nitrous oxide by curtain filler were 96.42%and 99.17%,respectively.The average removal rates of ammonia and nitrous oxide were 96.84%and 99.20%,respectively.(2)When the nitrogen concentration of the influent matrix was increased,the nitrogen removal performance of the two biofilm fillers increased in the middle and middle stages during the increase of the total nitrogen influent concentration from 314.61 mg/L to 1262.56 mg/L.The state of no obvious inhibition is much better than that of activated sludge anaerobic ammonium oxidation.At this time,the average removal rates of total nitrogen of the two fillers are 91.33%and 91.29%,respectively,and the average removal rate of ammonia nitrogen is finally stabilized to 97.31%.97.65%,the average removal rate of nitrosamine was stable to 97.60%,96.12%.According to the removal of matrix ammonia nitrogen and nitrous oxide,the optimal matrix ratio of anaerobic ammonium oxidation was 1:1.20.It was verified by impact load test that the anaerobic ammonium oxidation biofilm system has strong impact load resistance and recovery ability,and the beam filler performs better.(3)The biofilm still has higher activity,and the anammox ammonia oxidizing bacteria are obviously increased.Microscopic observation of the structural composition of the two fillers,the composition of the bundle filler is conducive to the stable attachment and proliferation of anaerobic ammonium oxidizing bacteria.The results of the metagenomic flux sequencing test showed that the dominant strains of the two kinds of filler biofilms were anammox bacteria,accounting for 25.9%and 35.89%of the curtain filler and the beam filler,respectively,and the tolerance to nitrous oxide.Candidatus Kuenenia has the highest performance.