进水底物对好氧颗粒污泥特性及微生物群落的影响

Effect of Influent Substrate on Characteristics of Aerobic Granular Sludge and Microbial Community

为了研究进水底物对好氧颗粒污泥(AGS)特性的影响,通过接种絮状污泥于序批式反应器(SBR)中以生活污水和模拟生活污水作为进水底物,对AGS形成过程中的污泥特性和微生物群落展开研究。研究表明:以模拟生活污水为进水底物,发现颗粒污泥内部以丝状菌为框架,通过对污泥的截留逐渐形成AGS,污泥沉降性能良好。随着AGS的形成胞外聚合物(EPS)组分中蛋白质(PN)含量增加显著,PN/PS由1.77上升至5.80,促进了AGS的形成和稳定性,且EPS含量与Zeta电位、污泥沉降指数呈负相关。连续投加Fe(OH)_(3)胶体抑制了NOB菌的活性,导致生活污水阶段污染物的去除效果较差;AGS形成后污染物的去除效果明显上升,特别是氮、磷污染物。生活污水阶段Candidatus_Microthrix菌属引起了系统内丝状菌膨胀,同时微生物群落丰富度、多样性逐渐降低。模拟生活污水阶段具有疏水性和分泌EPS功能的菌属丰度占比持续上升,例如:unclassified_o__Saccharimonadale(33.%→22.0%)、Zoogloea(3.0%→6.0%)、unclassified_f__Sphingomonadaceae(0.87%→3.1%)菌属等;促进了污泥颗粒化;同时随着污泥颗粒化程度提高,具有反硝化和除磷功能的菌属丰度占比持续上升,保证了AGS系统高效的脱氮除磷性能。

In order to study the effect of influent substrate on the characteristics of aerobic granular sludge(AGS),the sludge characteristics and microbial community during the formation of AGS were studied by inoculating flocculent sludge in a sequencing batch reactor(SBR)with domestic sewage and simulated domestic sewage as influent substrates.The research shows that:with simulated domestic sewage as the influent substrate,it is found that the granular sludge is framed by filamentous bacteria,and AGS is gradually formed by intercepting the sludge,and the sludge sedimentation performance is good.With the formation of AGS,the content of protein(PN)in the extracellular polymer(EPS)component increased significantly,and the PN/PS increased from 1.77 to 5.80,which promoted the formation and stability of AGS,and the EPS content was negatively correlated with Zeta potential and sludge sedimentation index.Continuous addition of Fe(OH)_(3) colloid inhibited the activity of NOB bacteria,resulting in poor removal efficiency of pollutants in domestic sewage stage.After the formation of AGS,the removal efficiency of pollutants increased significantly,especially nitrogen and phosphorus pollutants.Candidatus_Microthrix in the domestic sewage stage caused filamentous bacteria to expand in the system,and the richness and diversity of the microbial community gradually decreased.The abundance of bacteria with hydrophobic and EPS-secreting functions in the simulated domestic sewage stage continued to increase,such as unclassified_o__Saccharimonadale(33.0%→22.0%),Zoogloea(3.0%→6.0%),unclassified_f__Sphingomonadaceae(0.9%→3.1%).Promote the sludge granulation;at the same time,as the degree of sludge granulation increases,the abundance of bacteria with denitrification and phosphorus removal functions continues to increase,ensuring the efficient nitrogen and phosphorus removal performance of the AGS system.