污泥微膨胀的特性及N_s和DO对其影响

Effects of organic loading rate and DO on limited bulking and the study of its characteristics

摘要:

为了解决污水厂频繁发生的污泥膨胀问题,提出一种能在低氧条件下利用丝状菌的形态和生理特性进行污水处理的节能高效的"低氧丝状菌微膨胀"新方法.采用SBR反应器,通过好氧-缺氧的运行方式,研究了在微膨胀状态下,DO含量和有机负荷率对污泥沉降性的影响及氮、磷和COD的去除特性.试验结果表明:有机负荷率和DO含量各自在特定的范围内影响污泥沉降性,当有机负荷率大于0.25d-1时,单靠降低DO含量已经不能维持污泥微膨胀状态.低氧微膨胀不会恶化系统的硝化效果,由氮的物料平衡发现,每周期通过同步硝化反硝化可以去除掉20%的氮.低氧曝气前期能够出现释磷现象,系统内可以富集聚磷菌.

Abstract:

In order to solve the problem of sludge bulking which happened in wastewater treatment plant frequently,a notion named low DO limited filamentous bulking was put forward.It is a new energy-saving and high-efficient method to treat wastewater with the characteristics of morphology and physiology of filamentous bacteria under low DO concentration condition.The impact of DO concentration and organic loading rate (OLR) on sludge settleability and the removal characteristics of nitrogen,phosphorus and COD under limited filamentous bulking were investigated by using sequencing batch reactor (SBR) through operation in aerobicanoxic pattern.The results show that OLR and DO concentration affect sludge settleability in special range respectively.When OLR is larger than 0.25 d-1,limited filamentous bulking state can not be maintained by low DO concentration alone.Nitrification will not be deteriorated under low DO limited filamentous bulking condition,and about 20% nitrogen is removed through simultaneous nitrification and denitrification (SND) based on the mass balance of nitrogen.Aerobic phosphorus release is found in the initial stage of low aeration rate,and the system can enrich phosphorus accumulating organisms (PAOs).