全规模原水生物膜预处理系统细菌结构特征

Bacterial community structure of a full-scale biofilm system for raw water pretreatment

生物膜工艺因其处理成本低、运行性能高和二次污染少等优点,近年来常作为预处理工艺逐渐应用于污染原水净化,其生物膜菌群结构受到多种因素制约并影响系统去污性能.定期收集浙江某全规模原水预处理生物曝气池的生物膜样品,分析其菌群时空变化特征.结果表明,在原水生物膜预处理工艺中,生物膜菌群结构受运行时间和系统位置变化的影响较为明显.系统启动初期生物膜菌群多样性指数较低,随着系统运行逐渐增加,生物膜主要菌群为Proteobacteria、Bacteroidetes、Planctomycetes、Firmicutes、Actinobacteria、Verrucomicrobia、Acidobacteria和Gemmatimonadetes,其中Proteobacteria占优势地位.值得注意的是,原水生物膜预处理工艺生物膜生长有一定比例的蓝藻和病原菌,但其相对丰度较低.综合分析认为,原水生物膜预处理系统运行过程中有机物和氮素的去除由多种菌群相互作用共同完成.(图6表4参28)

In recent years, biofilm technology has been widely used for the purification of polluted raw water due to its advantages of low operation cost, high treatment performance, and lower secondary pollution. However, the community structure in biofilm pretreatment systems was restricted by multiple factors. In this study, biofilm samples in a full-scale aeration biofilm tank for raw water pretreatment were collected regularly to analyze the spatiotemporal variation characteristics of the biofilm microbial community. Experiment results showed that the community structure of biofilm was affected by the changes in operation time and the system location during the raw water biofilm pretreatment process. At the initial stage of the system start-up, the microbial diversity index of biofilm was low, and then gradually increased due to long-term operation. The main microbes in all biofilms of the full-scale pretreatment system were Proteobacteria sp., Bacteroidetes sp., Planctomycetes sp., Firmicutes sp., Actinobacteria sp., Verrucomicrobia sp., Acidobacteria sp., and Gemmatimonadetes sp. The Proteobacteria sp. was dominant. Additionally, there was a relatively low abundance of cyanobacteria and potentially pathogenic bacteria in the biofilm. The removal of organics and nitrogen in the biofilm system was accomplished by the interaction of various functional microbes, which contributes to the stable operation of the biofilm system.