| Wastewater denitrification was one of the most active research fields in environmental science and engineering in recent years.From initial nitrification-denitrification to methanol/methane denitrification,to simultaneous nitrification-denitrification,to partial nitrification-denitrification,the denitrification technology was constantly innovating and developing,and the anaerobic ammonia oxidation(ANAMMOX),which was the subversive technology for wastewater denitrification treatment had created a precedent for the practical application of functional bacteria in complex sewage treatment systems.In this paper,we studied on the denitrification performance and microbial community in different process and operating conditions based on ANAMMOX technology.Firstly,the low-matrix and high-flow culture method was used to realize the rapid start of the ANAMMOX system in 13 days with the mixed sludge inoculated in the UASB reactor and the dissolved oxygen in the influent water controlled by chemical reduction method.The chemical reduction deoxidation method is a feasible method which is simpler in operation,less time-consuming,cost effective,and has almost no adverse effect on the microorganisms in system compared with the conventional aeration deoxidation method.Based on high-throughput sequencing technology,it was concluded that the relative abundance of Planctomycetes was the largest,accounting for 31.56%.Candidatus_Kuenenia was the main genus in Planctomycetes,accounting for 74.1 1%.In addition,some representative genus in ANAMMOX reactor,such as the SMI A02 and the Candidatus_Brocadia were detected.Secondly,the process of anaerobic ammonium oxidation coupled with sulfur-based denitrification to removal inorganic nitrogen totally was studied.In this part,more than 85%of NH4+-N and NO2--N were removed in the ANAMMOX system,and the conversion of nutritional conditions from SAD to SMD maximized the comprehensive benefits of systemic denitrification and economics.The nitrogen removal rate was as high as 97%,and the total effluent nitrogen was less than 10 mg/L,achieving the purpose of deep denitrification.The relative abundances of the main functional genus in the SAD stage were Thiobacillus and Sulfurimonas,which were 31.9%and 17.7%respectively.The abundances of the two genus were decreased,and Gemmobacter and Trichococcus played more and more important role in mixotrophic conditions.At last,the molecular ecological network analysis of SAD and SMD systems was carried out,and the similarities and differences of microbial interactions between the two systems were further studied.The influence of organic carbon sources on the system and the key species in SAD and SMD systems were clarified.Finally,high salt domestication of the ANAMMOX system was investigated in this part,and the nitrogen removal performance,microbial diversity and community structure of the system under different salinity gradients(0/2.5/5/7.5/10/15/20/30 g/L)were studied.The results showed that the change of salinity mass concentration had less effected on the removal rate of NH4+-N and the rate remained above 95%,When the salinity concentration reaches 30g/L,while the removal rate of NO2--N is greatly inhibited.When the salinity concentration was between 0-15 g/L,the removal rate of NO2--N was reduced from 95%to 90%and the removal rate was reduced from 90%to 70%at the range of 20-30 g/L.The Planctomycetes was the dominant bacteria which abundance increased from 28.98%to 45.21%.The abundance of Candidatus_Kuenenia increased from 26.9%to 34.7%,which was the dominant genus determining the nitrogen removal performance of the system in a high salt environment. |
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