The Startup Of ANAMMOX System And The Microbial Community Structure Analysis

Anaerobic ammonium oxidation(ANAMMOX)proeess is a new type biological nitrogen-removal technology with higher nitrogen removal loading and low cost,which is the domestic and international research hot point at present.But a main drawback of the application of anammox process is a long start-up period due to slow growth rates of anammox bacteria and strict survival conditions.A effective method of the rapid enrichment of anammox bacteria is improving the system retention capability for anammox bacteria.Accordingly,this thesis used UASB system loading with two different carriers to study the impact of different carriers on the enrichment of anammox bacteria, to investigate the nitrogen-removal performance of anammox system startup,and to analysis the variation characteristics of microbial community.The main results of this thesis are as follows:(1)The comparison of the anammox system Startup with UASB reactor loading with two different carriers indicated that the startup time of the UASB reactor(R1) loading with activated carbon-based polythene carrier is shorter than the UASB reactor(R2) loading with normal polythene carrier, although they all successfully startup the anammox system.The R1 reactor successfully startup the anammox system in the 86 d,and the R2 reactor take 100 d.The reason is that the activated carbon-based polythene carrier has bigger specific surface area than the normal polythene carrier,and activated carbon has many micropores,which are in favour of the biofilm formation and the enrichment of anammox bacteria.The largest nitrogen loading rate and the largest nitrogen removal rate of the R1 reactor is respectively 2155.67mgN·L-1·d-1 and 1855.43 mg N·L-1·d-1,and the largest nitrogen loading rate and the largest nitrogen removal rate of the R2 reactor is respectively 2121.99mgN·L-1·d-1 and 1815.12mgN·L-1·d-1.(2)Analysis substrate purification efficiency on different height in R1 reactor indicated that the ANAMMOX mainly focus on the 37 cm range at the bottom of the reactor during the anammox system startup and operation process.The substrate removal variation curve with height appear a significant difference between the high influent ammonia nitrogen concentration(the influent ammonia nitrogen concentration is greater than 350mg/L) and the low influent ammonia nitrogen concentration(the influent ammonia nitrogen concentration is less than 200mg/L). It might be because the higher FNA concentration at the bottom of the reactor inhibits the activity of anammox bacteria,when the the influent ammonia nitrogen concentration is greater than 350mg/L.(3)Analysis the microbial community structureon different height in R1 reactor indicated that the microbial community structure diversity of four different height sludge from the height of 7cm to the height of 37 cm in the reactor is approximate in every operation stage, respectively,and the microbial community structure diversity on different height in reactor is reducing with the reactor operation time longer and the improvement of the influent substrate concentration.Jettenia and Brocadia which are the anammox bacteria at a genus level were detected in the reactor during the 3 operation stages.The enrichment of the Jettenia and the Brocadia mainly focus on the height of 37 cm in the reactor with the reactor operation time longer and the improvement of the influent substrate concentration.(4)Analysis the microbial community structure succession of the different operation stages in the UASB anammox System indicated that the microbial community structure diversity in the reactor is reducing during the anammox startup with UASB reactor.Jettenia,Brocadia and Kuenenia which are the anammox bacteria at a genus level were detected in the reactor.