硝化细菌AOB与NOB衰减速率实验测定

污水生物处理过程中由于硝化反应分两步进行,因而对于硝化细菌的衰减速率也应该分别测定.通过实验测定了氨氮氧化细菌(AOB)和亚硝酸氮氧化细菌(NOB)在好氧饥饿状态下的衰减速率,实验结果显示,AOB和NOB具有不同的衰减特征.前者在衰减过程中其活性匀速下降,而后者的活性则是先迅速下降再平缓降低,通过对比分析还发现,SBR系统中AOB和NOB的衰减速率差异较大,而在常规活性污泥系统中AOB和NOB的衰减速率基本相当.

Experimental determination of the decay rate of nitrifying bacteria:AOB and NOB

Because nitrification is a two-stage process, the decay rates of Ammonia Oxidizing Bacteria (AOB) and Nitrite Oxidizing Bacteria (NOB) need to be separately measured. In this work, the decay rates of both AOB and NOB were experimentally determined under aerobic starvation conditions, using sludge samples from a lab-scale sequencing batch reactor (SBR) nitrifying system. The decay features of AOB are different from those of NOB. The activity of AOB decreased smoothly over the whole decay period, whereas that of NOB dropped sharply within the first day and then became smooth over the following₆ days. Comparatively, the decay rates of AOB and NOB from ordinary activated sludge systems are of the same order of magnitude, but are quite different from those from the SBR nitrifying system.