The Influence Factors Of Nitrogen Removal Of Artificial Municipal Waste-Water Based On Anammox

Anaerobic ammonia oxidation（ANAMMOX）is a process that more economical and green than traditional nitrogen removal.Based on the characteristics of municipal wastewater,a lab scale anaerobic moving biofilm reactor（AMBBR）was constructed to treat simulated municipal wastewater.The effects of three elements of low concentration,organic matter and low temperature and different starting conditions on the nitrogen removal performance of the reactor were investigated.Meanwhile,the microbial community composition and abundance in different reactors under different conditions were analyzed by high-thought sequencing analysis,and analyzed the way of nitrogen removal based on biochemical stoichiometry,which provides data support for the optimization of anaerobic ammonia oxidation process.The main results are as follows:（1）Changed the initial concentration from 39.7 mg NH₄⁺-N/L to 12.8 mg NH₄⁺-N/L and then recovered to 24.8mg NH₄⁺-N/L,the average removal of NH₄⁺-N,NO₂^--N and TN were 95.3%to 65.2%to 85.3%,95.7%to 96.6%to 97.7%and 38.3%to 62.6%to 81.2%,respectively.The low concentration of nitrogen decreased the efficiency of nitrogen removal,but it recovered with the increase of concentration.（2）The stability of the system was affected by adding 100 mg/L organic matter,but the average removal efficiency of NH₄⁺-N and TN increased after stable operation.The addition of proper organic matter promoted anammox reaction.（3）Decreased the temperature from 35±1℃to 31±1℃,the removal efficiency of nitrogen has no significant change.After reducing to 25±1℃,the system was affected by low temperature and the removal efficiency of nitrogen is significantly reduced.The removal efficiency of nitrogen can be recovered when adapted the low temperature.（4）The starting speed under low concentration of ammonia nitrogen was the fastest and the next was low temperature;the removal rate of NO₂^--N was faster than that of NH₄⁺-N.After stable operation,the nitrogen removal efficiency increased to more than 80%in the short term under the low concentration of ammonia nitrogen and organic matter,but the recovery of nitrogen removal efficiency with the low temperature conditions was slower.（5）Themaindominantbacteria（phylum）includedProteobacteria,Bacteroidetes,Acidobacteria,Firmicutes,Actinobacteria,Planctomycetes and Chloroflexi.The abundance of Planctomycetes（ANAMMOX bacteria）decreased with the decrease of concentration,but its abundance continued to increased after the concentration was restored,and the addition of organic substances promoted the significant growth of Planctomycetes in the biological carrier,and low temperature restricted the growth of Planctomycetes and resulted in the decrease of its abundance.（6）The nitrogen removal pathway included in the reactor:anaerobic ammonia oxidation,nitrification,nitrite oxidation and denitrification,and the anaerobic ammonia oxidation process has always been the dominant removal pathway.