溶解氧对序批式全程自养脱氮工艺运行的影响

在常温22~26℃下,接种成熟的全程自养脱氮(CANON)污泥至2个相同的SBR反应器,通过设置不同的初期DO及不同的DO梯度,考察了DO控制策略及DO值对CANON工艺脱氮性能,稳定性及污泥形态的影响.结果表明,初期DO为0.05~0.10mg/L的反应器可以稳定运行,氨氮和总氮的平均去除率分别为99%和85.4%,而初期DO为(0.40±0.5)mg/L的反应器的氨氮和总氮平均去除率分别为99%和0;在反应器运行稳定之后,逐渐增加DO浓度, DO为0,0.2,0.4,0.5mg/L时的厌氧氨氧化反应速率分别为35.95,23.89,31.50,19.25mgN/(L·h),延时曝气2h后反应器仍可正常运行.在一定DO范围内,CANON反应器的活性随着DO的升高而升高,较高DO对接种初期的CANON反应器冲击较大且不可逆,对稳定运行的CANON反应器的影响较小;但是当CANON工艺稳定运行之后,短时高DO对CANON工艺的影响是可逆的.显微镜照片显示稳定运行的CANON反应器内出现了颗粒化的趋势.

The effect of dissolved oxygen on running CANON process in sequencing batch reactor

The sludge that deriving from a stable CANON biofilter was seeded to two same SBR reactors at room temperature (22~26℃), in which the influence of DO on the nitrogen removal, stability and sludge morphology of CANON process were studied by setting different initial DO and DO gradient. The results showed that the reactor with the initial DO of 0.05~0.1mg/L could run stably with the ammonia and TN removal efficiency of 99% and 85.4%, respectively, while the reactor with initial DO of (0.40±0.5)mg/L showed rather lower removal efficiencies of 99% and 0, respectively. DO concentration was increased gradually from 0to 0.2, 0.4, 0.5mg/L, correspondingly, the anaerobic ammonia removal rate reached to 35.95, 23.89, 31.50, 19.25mgN/(L·h), respectively. Moreover, the reactor could still run normally after two hours’ extended aeration The activity of the CANON reactor went up with the increase of DO within a certain DO range, and the higher DO presented a large and irreversible impact on the early vaccinating CANON reactor while showed little and reversible influence on the stable CANON reactor. Micrographs indicated the tendency of sludge granulation in the stable CANON reactor.