密集生长条件下丝状菌结构分析

从丝状菌结构入手,控制条件使丝状菌致密生长是控制丝状菌污泥膨胀的一种新思路。提出了"节点密度"的概念,以表征菌丝体之间的缠绕特征。研究发现,丝状菌菌丝体的节点密度及其网眼的椭圆度与SVI分别呈正相关和负相关性。另外,实验过程中丝状菌密集生长形成质量较大的丝状菌絮体,该絮体具有良好的泥水分离效果和较低的SVI值。但丝状菌大絮体会造成反应器中局部溶氧不均,降低传质效率,进而导致大絮体解体,且氨氮去除率不高。关于丝状菌大絮体如何形成且长时间稳定存在的问题,还有待于进一步研究。

Structure of filamentous microorganisms under overspreading growth condition

Densification of filamentous sludge, by means of improving sludge structure, may be a new approach for the bulking sludge control. "Node density" was introduced to characterize the winding feature of mycelia. Results show that the node density of filamentous was positive correlated with SVI,while the ovality of filamentous mesh was negative correlated with SVI. Additionally,large bioaggregates of filamentous under overspreading growth conditions could be significantly found in the reactor, exhibited low SVI,and they could be easily separated during settling periods. However,the large bioaggregates also caused ununiform distribution of dissolved oxygen in the reactor and decreased oxygen mass transfer efficiency,which may contribute to the disintegration of the large bioaggregates,and the ammonia nitrogen removal efficiency is not satisfied.The formation mechanism of large bioaggregates of filamentous is still unclear and thus needs further investigation.