SBR短程硝化工艺的启动及稳定运行适宜DO探究

Suitable Dissolved Oxygen(DO) for Startup and Steady Operation of SBR Partial Nitrification Process

摘要：在温度21～23℃时，通过考察溶解氧（DO）对短程硝化快速启动的影响发现，ρ（DO）为0．25～1．25mg／L时均能启动短程硝化，其中0．25～0．75mg／L属于实现短程硝化快速启动的ρ（DO）范围；p（DO）为0．25～0．50mg／L与0．50～0．75mg／L对快速启动的效果相当，主要是因为当ρ（DO）为0．25～0．50mg／L时，虽然氨氧化菌（AOB）的竞争优势更加显著，但是AOB自身利用基质倍增所需的时间却会增大．在短程硝化的运行阶段，当p（DO）较高（1．50～1．75mg／L）时，可以通过间歇性大幅降低ρ（DO）至0．50～0．75mg／L的方法实现短程硝化的长期稳定运行．对稳定运行后期的污泥样品进行微生物分析，总细菌通用引物分析结果表明：AOB、亚硝酸盐氧化菌（NOB）占总细菌的比例分别为22．50％、3．75％，其中，亚硝化单胞菌属（Nitrosomonas sp．）是AOB的优势菌属，比例高达总细菌的17．50％．

In SBR process,rapid startup of partial nitrification was not only associated with the number of cycles needed for startup,but also with nitrification time(nitrification rate) of each cycle.When temperature was 21~23℃,the effect of dissolved oxygen(DO) on partial nitrification indicated that DO mass concentration of 0.25~1.25 mg/L was beneficial to startup of partial nitrification in which ρ(DO)of 0.25~0.75 mg/L was superior for rapid startup.The effects of ρ(DO) of 0.25~0.50 and 0.50~0.75 mg/L on rapid startup of partial nitrification were fair,mainly because when ρ(DO) was 0.25~0.50 mg/L,although competitive advantage of AOB was more significant,doubling time of AOB increased.During the operation of partial nitrification in which ρ(DO) was about 1.50~1.75 mg/L,long-term steady operation achieved by reducing ρ(DO) to 0.50~0.75 mg/L at intervals.Molecular biology was used to analyze the sludge sample taken from steady operation period.Results of general primers analysis showed that the proportion of AOB and NOB in total bacteria was 22.50%and 3.75%respectively,especially,Nitrosomonas sp.was the dominant bacterial genus in AOB,and its proportion of the total bacteria was 17.50%.