SBR中不同曝气方式下CANON工艺的启动与运行

摘要

In the operation of completely autotrophic nitrogen removal over nitrite ( CANON) process, a recently developed new type of nitrogen removal, the improper control of DO can easily lead to the decline or even collapse of the nitrogen removal rate. The key to the stable operation of the CANON process is reasonable control of dissolved oxygen inside the reactor. Given controversies of the present findings on the startup and long running of CANON in different aeration modes, the startup and performance of CANON process were tested in SBR with two different aeration strategies—intermittent aeration (R1) and the continuous aeration (R2).Results showed that the CANON was successfully developed in both R1and R2 within 21 d and 27 d. After extended aeration damage, CANON of R1and R2 fully recovered within 25 d and 33 d on conditions of HRT change and run cycle increase. The final TN removal rates of R1 and R2 were 84.32% and 73.62%.The results further showed that both alternating nitritation/anammox and simultaneous nitritation/anammox contributed to N-removal in SBR, and their contributions in R1 accounted for 58.54% and 24.7% (86 d). The bioactivity of ammonia oxidizing bacteria (AOB) and anaerobic ammonia oxidizing bacteria ( AnAOB) in R1 was higher than that of R2, while the bioactivity of nitrite oxidizing bacteria ( NOB ) showed a contrary result. Intermittent aeration is an effective means to obtain stably high TN removal.%全程自养脱氮工艺(CANON)是近年来发展起来的一种新型脱氮工艺,在CANON的运行过程中,DO的控制不当很容易引起系统脱氮率下降,甚至崩溃.合理控制反应器内部溶解氧是CANON工艺稳定运行的关键.目前,关于不同曝气方式下CANON启动与运行的研究结果还存在争议,为此,本实验在序批式反应器SBR中分别采用间歇曝气SBR(R1)和连续曝气SBR(R2),研究不同曝气方式下启动CANON及其遭到延时曝气破坏后的恢复.结果表明:R1和R2分别在第21天、27天成功启动CANON.进行延时曝气破坏后,在只改变HRT与增加运行周期的条件下,R1和R2分别经过25 d、33 d成功恢复CANON.最终R1和R2的总氮去除率分别为84.32%、73.62%.在SBR中可以通过同时亚硝化/厌氧氨氧化和交替亚硝化/厌氧氨氧化两种途径提高总氮去除率,R1中两者所占比例分别为24.7%、58.54%(第86天).R1内亚硝化菌(AOB)和厌氧氨氧化菌(AnAOB)具有较高的活性,硝化细菌(NOB)被抑制或淘洗得较为彻底.间歇曝气在节省运行时间的同时可以稳定实现较高的总氮去除率.