污泥作为污水厂内碳源的水解特性及工艺选择

Hydrolysis Characteristics of Sludge as Internal Carbon Source for WWTP and Hydrolysis Process Selection

随着各地污水厂出水水质对氮、磷要求的日益提高,强化脱氮除磷成为必然要求,但是我国多数污水厂由于多种原因导致进水碳源不足,尤其是进水SCOD、VFAs的匮乏,直接影响了生物脱氮除磷的效率,甚至不得已采用人工投加外碳源脱氮或者化学除磷方式以满足严格的出水氮、磷要求,但这无疑大大提高了污水厂的产泥率及运行成本。充分挖掘污水厂的"内碳源",利用污泥水解产生VFAs,不仅能有效提高除磷脱氮效率,而且可以降低污水厂的污泥产量,是可持续的资源化技术。比较了初沉污泥和活性污泥的水解特性差异,介绍了污泥水解工艺的常用构型及参数选择,以及国内外一些成功的实施案例。

With increasingly stringent discharge limits for effluent nitrogen and phosphorus from WWTPs, it is necessary to enhance nitrogen and phosphorus removal. However, most of them are en- countering the problem of insufficient influent carbon source due to various reasons. Especially, the lack of SCOD and VFAs leads to lower removal efficiency of nitrogen and phosphorus. In some plants, the external carbon source or phosphorus-removal chemicals has to be added in manual to meet the stringent effluent nitrogen and phosphorus standards, which obviously results in much sludge production and heavy operation cost. Making full use of ＂internal carbon source＂ and VFAs produced by sludge hydrolysis is a sustainable technology, which can not only increase nitrogen and phosphorus removal efficiency, but also decrease sludge production. The difference in hydrolysis of primary sludge and activated sludge is com- pared. The sludge hydrolysis process configuration and parameters selection, as well as some successful implementation cases, are also presented.