污泥比例强化CANON系统抵御快速降温效能及机理

Mechanism and efficiency of the CANON system against rapid cooling enhanced by flocculent sludge ratios

探究了3种不同颗粒及絮状污泥比例(高颗粒系统10:1~30:1;等量系统1:1~1:1.5;高絮状系统1:10~1:30)的单级自养脱氮系统(CANON)抵御快速降温的效能和机制.结果表明,CANON系统在30℃稳定运行后快速降温至10℃时,各系统的总氮去除负荷(NRR)均大幅下降,但等量系统的NRR始终高于其他系统.各系统的功能菌活性均与温度呈现出正相关关系,AAOB活性的下降幅度大于AOB和NOB的幅度,但等量系统中AAOB活性的下降幅度小于其他系统;快速降温不影响颗粒与絮状污泥功能菌的空间异质性和活性分布情况,但等量系统的空间异质性最为显著,能够较好的发挥颗粒和絮状污泥各自的作用,抵御快速降温的能力优于其他系统.

This study explored the efficiency and mechanism of a single-stage autotrophic nitrogen removal system(CANON)with three different particle and flocculent sludge ratios(high particle system 10:1~30:1,equivalent system 1:1~1:1.5,high flocculent system 1:10~1:30)to resist rapid cooling.During cooling of the CANON system to 10℃after stable operation at 30℃,the total nitrogen removal rate(NRR)of each system decreased significantly;however,the NRR of the same system was always higher than that of other systems.The activity of functional bacteria in each system was a positively correlated with temperature,and the declining range of aerobic ammonia-oxidizing bacteria(AAOB)activity was higher than that of the ammonia-oxidizing bacteria(AOB)and nitrite-oxidizing bacteria(NOB),but the declining range of the AAOB activity in the same system was lower than that of other systems.Therefore,rapid cooling did not affect the spatial heterogeneity and activity distribution of granular and functional flocculent sludge bacteria.However,the spatial heterogeneity of the equivalent system demonstrated the highest significance,thus indicating that this system could better serve the roles of particles and floc sludge.Furthermore,its ability to resist rapid cooling was also better than that of the other systems.