Study On Autotrophic Ammonium Removal With Airlift Reactor

Anaerobic ammonium oxidation process and related technology is increasingly being used in nitric wastewater treatment field. The main principle of the process is parts of the ammonium in the wastewater is first oxidized to nitrite by ammonium oxidizing bacteria (AOB),and then the anaerobic ammonium oxidation bacteria (Anammox) convert the remaining ammonium and nitrite to nitrogen gas. Compared to traditional nitrogen removal process, Partial Nitrification-ANAMMOX process has advantages such as low energy consumption, gh efficiency and green environment protection.Two stage nitrogen removel process such as PN-ANAMMOX and SHARON-ANAMMOX had a broad prospect of application.However,two stage process needs more energy consumption and space,more and more researchers investigated one stage process recently,such as Netherlandish scholars CANON process and Janapese scholars SNAP process. That two process above-mentioned achieves high nitrogen removel,there still remains problems such as bacteria erosion and reaction condition is different to control.An internal airlift loop reactor was designed for one-stage Partial Nitrification-ANAMMOX nitrogen removal process. Synthetic waste water was used, K1 carriers was used for AOB and Vilence carriers was used for ANAMMOX. Ammonium concentration nitrite concentration.By measuring ammonium concentration nitrite concentration and nitrate concentration,this study investigated Partial Nitrification- ANAMMOX nitrogen removal performances.The main contents of the dissertation are as follows:①sequencing batch reactor (SBR) was used to culture biofilm of AOB with Kl carriers.When the influent ammonium concentration was 200mg/L, the effluent concentration of ammonium and nitrate was respectivelylower than 10mg/L and 20mg/L. Well-grown AOB could be observed with scanning electron microscope.②Partial Nitrification-ANAMMOX process was set-up and running with the airlift reactor. The reactor was operated for 240 days, the temperature was 35℃, pH value was 7.5～8.0. Intermittent aeration was used in the reactor, the structure of inner cylinder and outer cylinder realized the septation of anaerobic zone and aerobic zone, the average DO of inner cylinder and outer cylinder was0.8～2.2mg/L and1.5～3.5mg/L,which provided suitable grown condition for AOB and ANAMMOX.③The influent ammonium concentration was 50～200mg/L, total nitrogen loading was 21～280g N/m3d, nitrogen removal efficiency constantly improved in the system,total nitrogen rate was from less 30% to 75% in 120 day. That means that nitrification and ANAMMOX bacteria could synergistic grown in different parts in a single reactor and got excellent nitrogen removal efficiencies.⑤ The influence of impact loading such as C/N ratio and temperature to stable running of reactor was studied. The results showed that when the C/N ratio was more than 1, heterotrophic bacteria in the reactor inhibited the Partial Nitrification-ANAMMOX process.When the room temperature was 13-26℃,the removal rate of total nitrogen had declined in some extent but still keep a high level.