Effect Of Sponge Iron On The Coupling Of Anaerobic Ammonia Oxidation And Denitrification

With the development of the economy,the nitrogen cycle has been gradually destroyed,and nitrogen pollution has become one of the most pressing problems in the world.Although the traditional denitrification process has a good removal effect on nitrogen in the water,it has high energy consumption and a large area.The anaerobic ammonia oxidation process,as a new process with high nitrogen removal efficiency and low energy consumption,has become a research hotspot for environmental protection workers.Since anammox bacteria are sensitive to external conditions,there are many factors that inhibit them.In this experiment,sponge iron fillers were added to study the start-up and coupling reactions of anaerobic ammonia oxidation,achieving the goal of simultaneous nitrogen and carbon removal.In the reactions of nitrogen and sponge iron larger dosage,smaller particle size is favorable for converting nitrogen under acidic conditions.Sponge iron can convert NO₃^--N in water into NH₄⁺-N and N₂.In the anaerobic ammonia oxidation start-up process,an Anaerobic Sequencing Batch Reactor?ASBR?was used.After 140 days of startup,the ASBR reached a steady state when the reactor water fed with sponge iron was effective and effective.The problem of NO₃^--N accumulation often appears during start-up of anaerobic ammonia oxidation reactors.In the study of the coupling reaction between anammox and denitrification,the optimum operating conditions for the coupling reaction were determined by orthogonal experiments:HRT for 48 h,pH 6.0,and temperature 35°C.Under optimal operating conditions,different DO,substrate concentrations and C/N on nitrogen removal,and the tolerance to phenol of anammox bacteria were studied.The results showed that the reactor with sponge iron is better than the reactor with no added sponge iron in TN removal.High-throughput sequencing was used to analyze the microbial species distribution of the microorganisms under different C/N conditions.More anammox bactria were found in the reactor with sponge iron,for example,the quantity of Candidatus Kuenenia was 11.83%higher than in the reactor without sponge iron.In this thesis,sponge iron was used as a filler to start the anaerobic ammonia oxidation reactor and the factors influencing anaerobic ammonia oxidation and denitrification coupling was investigated.t not only provides a new idea for the cultivation of anaerobic sludge,but also provides basic data and practical experience for the start-up of anaerobic ammonia oxidation reactor.