采用稳定运行的CANON颗粒污泥,探究不同DO浓度对CANON工艺脱氮性能的影响.结果表明,当DO小于0.46mg/L时,CANON反应器可在连续曝气方式下运行.随着DO从0mg/L升高至0.46mg/L,系统脱氮速率从0提高到50.88mg N/(L·h);当DO大于0.46mg/L时,CANON反应器必须以间歇曝气方式运行;随着DO从0.46mg/L升高至2.8mg/L,系统脱氮速率从50.88mg N/(L·h)降低为41.84mg N/(L·h).CANON反应器在DO为0.46mg/L时脱氮速率最高,达到50.88mg N/(L·h),污泥脱氮负荷为0.45kg N/(kg MLSS·d).CANON颗粒污泥大小及结构对AOB和anammox菌的活性影响较大:由于液相向颗粒污泥的传质阻力,AOB的DO半饱和常数为0.77mg/L;而对于anammox菌,当DO小于0.46mg/L时,随DO浓度上升,其活性下降缓慢;当DO大于0.46mg/L时,随DO浓度上升,其活性迅速下降;当DO超过1.0mg/L时,anammox菌接近失活.%Impact of the different DO concentrations on the nitrogen removals was studied using the granular sludge in a completely autotrophic nitrogen removal over nitrite (CANON) process. The results showed that at DO concentration below 0.46mg/L, the CANON process could run at a continuous aeration mode, and the nitrogen removal rate of the CANON process increased from 0 to 50.88mg N/(L?h) with DO concentration increasing from 0 to 0.46mg/L; when the DO concentration was higher than 0.46mg/L, the CANON process could run at an intermittent aeration mode and nitrogen removal rate decreased from 50.88mg N/(L?h) to 41.84mg N/(L?h). So, the CANON process had a maximum nitrogen removal rate of 50.88mg N/(L?h) at DO concentration of 0.46mg/L, with a sludge nitrogen load of 0.45kg N/(kg MLSS?d). On the other hand, the activity of both ammonia oxidizing bacteria and anammox bacteria was influenced by the particle size and structure of the sludge. Due to the mass transfer resistance from liquid to the sludge particles, the DO half saturation coefficient of AOB was 0.77mg/L. As to anammox bacteria, its activity decreased slowly when DO concentration was less than 0.46mg/L, and decreased sharply as DO concentration increased from 0.46to 1.0mg/L; when DO concentration was higher than 1.0mg/L, the anammox activity was rarely observed.
展开▼
