Influence of different substrates on the formation and characteristics of aerobic granules in sequencing batch reactors

The effects of different substrates on the aerobic granulation process were studied using laboratory-scale sequencing batch reactors （SBRs）. Four parallel granules sequencing batch reactors （GSBR）： R1, R2, R3, and R4 were fed with acetate, glucose, peptone and fecula, respectively. Stable aerobic granules were successfully cultivated in R1, R2, R4, and smaller granules less than 500 μm were formed in R3. Morphology and the physic-chemical characteristics of aerobic granules fed with different carbon substrates were investigated by the four reactors operated under the same pressure. The aerobic granules in the four reactors were observed and found that peptone was the most stable one due to its good settleability even after a sludge age as short as 10 d. A strong correlation was testified between the characteristics of aerobic granules and the properties of carbon substrates. The stability of aerobic granules was affected by extracellular polymer substances （EPS） derived from microorganism growth during feast time fed with different carbon substrates, and the influence of the property of storage substance was greater than that of its quantity. Optimal carbon substrates, which are helpful in the cultivation and retention of well-settling granules and in the enhancement of the overall ability of the aerobic granules reactors, were found.

基于CANON系统颗粒污泥耦合生物膜工艺脱氮性能及微生物特征研究

为实现自养生物脱氮,通过颗粒污泥与生物膜进行同步驯化构建一种GSBR反应器。研究进水NH_(4)^(+)-N浓度、DO浓度、上升流速对GSBR反应器脱氮性能的影响,并采用SEM、高通量测序等技术分析污泥表观特征及微生物组成。结果表明,进水NH_(4)^(+)-N浓度、DO浓度、上升流速对GSBR反应器脱氮性能具有重要影响,分别在150 mg·L^(-1)、0.8 mg·L^(-1)、3.5 m·h^(-1)时脱氮性能较好。系统总氮去除负荷最大值为1.76 kgN(m3·d)^(-1),高于生物膜系统并略低于颗粒污泥系统,抗冲击负荷性能及对DO适应范围相对颗粒污泥更优,低水平时DO浓度及上升流速提升促进亚硝化并抑制Anammox。污泥形态研究表明,GSBR反应器可实现颗粒污泥与生物膜同步驯化,接种后颗粒污泥平均粒径增加50%,颗粒污泥与生物膜表观形态差异显著,高通量测序结果显示AOB主要分布在生物膜中,AnAOB则在生物膜与颗粒污泥中均有分布,尤其以颗粒污泥分布最高,生物膜与颗粒污泥协同完成系统自养脱氮过程。研究为CANON工艺工程应用研究提供参考。