| With the development of industrialization and urbanization,the content of nitrogen in the water increases seriously,and it has a great impact on human life and the natural environment.With the treatment of low C/N ratio,high concentration of ammonia-nitrogen wastewater,traditional process of nitrification and denitrification treatment costs are too high,and efficiency is too low.So development of efficient and low power consumption of the new force is in emergency.Anammox biological process has the advantage of energy saving,covering small area,no addition of organic carbon sources,less sludge production,no secondary pollution.It has wide application markets in this field.But it also has many difficult problems to make Anammox biological process expand the actual works.We used a 15 L cylindrical ASBR reactor in this topic,and the sludge was anaerobic sludge which was from the wastewater treatment plant.We studied on the morphological changes and operational characteristics of sludge between anammox process.Experimental studies had found that at pH 7.8,temperature at 33 degrees Celsius,the reactor experienced a lag phase,activity level and activity of the sludge stabilization phase three phase.Finally,we used 115 days to start up ASBR successfully.Firstly the sludge changed from black to brown,eventually it became pink.In the load stage,when the influent ammonia nitrogen and nitrite nitrogen were 100 mg/L and 135 mg/L,ammonia nitrogen and nitrite nitrogen removal rate were 90%and 94%respectively,total nitrogen removal rate was 75%,total nitrogen removal rate was 0.19 kg/m3 · d,water quality and other indicators could be in the optimum state.Based on the successful start-up of anammox reactor,this experiment explored some factors such as pH,IC,substrate concentration and metal ions which may effect anammox bacteria.Experimental studies had found that when pH was 8,IC was 156 mg/L,nitrite nitrogen/ammonia nitrogen in the water was 0.8-2.04,anaerobic ammonia oxidation activity could reach its maximum.The right amount of metal ion short term could help to promote the growth of anaerobic ammonium oxidizing bacteria metabolism.When the concentration of Fe3+ was 6 mg/L,the concentration of Cu2+ was lmg/L,the concentration of Zn2+ was 4 mg/L,their efficiencys of nitrogen removal by anaerobic ammonium oxidation increased 22%,16.5%and 7.2%compared with the control group.And in optimal condition of metal ions for long trial found that group of copper and zinc ions were in the medium-term phenomenon of inhibition,mixed group did not find great inhibiting or growth,only iron group had maintained a good role.Compared to control group,it increased 21.9%in efficiency of nitrogen removal by anaerobic ammonium oxidation.We used mature anammox sludge in ASBR reactor and self-cultivation of anaerobic sludge to do two groups of shake flask test.We found anammox bacteria and denitrifying bacteria could occur under certain conditions the synergy.And anammox bacteria can occur under certain conditions of anaerobic ammonium oxidation and denitrification in two responses.When the C/N ratio was less than 0.5,both sets of tests were dominated by anaerobic ammonium oxidation reactions.When the C/N ratio were 1.0 and 1.5,two sets of tests of anaerobic ammonium oxidation and denitrification in coupling reactions worked best.Total nitrogen and COD removal efficiency was also great.When the C/N ratio were 2.0 and 2.5,denitrification became the dominant reaction and anaerobic ammonia oxidation activity was inhibited.When the C/N ratio was 3.0,denitrification became the dominant reaction.Total nitrogen and COD removal efficiency is poor,and the water quality deteriorated seriously. |
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