中试SBR内好氧颗粒污泥培养和微生物群落变化

利用实际城市污水在SBR中试系统中培养好氧颗粒污泥(AGS),考察AGS对污染物的去除特性,同时利用Illumina MiSeq高通量测序对成熟的AGS和絮体污泥中的细菌群落组成进行对比研究,分析污泥好氧颗粒化原因,以期为AGS的工程化应用提供理论依据。结果表明:通过逐渐缩短沉淀时间的方式能够在30 d内培养出粒径在220μm以上的AGS;并且在180 d时系统内颗粒化趋于成熟,AGS占比达95%以上。成熟的AGS能够实现同步硝化反硝化,出水TN低于10 mg/L,TN去除率稳定在85%以上。通过对AGS与絮体污泥中细菌群落多样性的对比分析可知,成熟的AGS细菌群落多样性降低且群落组成发生显著变化。Proteobacteria是絮体污泥中最优势的细菌门,而在 AGS中,最优势的细菌门为Bacteroidetes,其次是Proteobacteria。Flavobacterium、Aquimonas 和 Candidatus Accumulibacter 在 AGS 中的相对丰度高于絮体污泥,说明这些菌属可能促进絮体污泥形成AGS。

Aerobic Granular Sludge Culture and Microbial Community Analysis in Pilot-scale SBR System

The aerobic granular sludge ( AGS) was cultivated using the municipal sewage in the pilot-scale SBR system. The removal characteristics of AGS were investigated during aerobic sludge granulation. And the difference of bacterial community composition in AGS and activated sludge were investigated using Illumina MiSeq high-throughput sequencing to reveal the granulation mechanisms. After operation of 30 days, the AGS with a diameter of more than 220 jjim was developed by adjusting settling time. After 180 days, the AGS became mature and the proportion of AGS in the system was more than 95%. Results showed that the AGS could achieve simultaneous nitrification and denitrification in the pilot-scale SBR. The removal rate for total nitrogen ( TN ) was stable above 85%, and the effluent concentration was less than 10 mg/L. The diversity of bacterial community decreased after the formation of AGS. The composition of bacterial community changed significantly. Proteobacteria was the most dominant phylum in activated sludge. But, in AGS, the most dominant phylum was Bacteroidetes followed by Proteobacteria. The relative abundance of Flavobacterium , Aquimonas and Candidatus Accumulibacter in AGS was higher than that of activated sludge, indicating that these genuses might play an important role in the formation of AGS.