影响微生物聚集体的聚集度的因素分析

提出了包括两层含义的污泥聚集度的概念(一是污泥空间上的物理聚集,即密实度;二是微生物种类的聚集),并将膨胀污泥、絮体污泥和颗粒污泥作为污泥聚集度的3种典型状态,以现有污泥膨胀控制理论为基本参照,结合好氧颗粒污泥形成条件,探讨了操作条件对污泥聚集度的影响:①较高的基质梯度、溶解氧水平和有机物的复杂程度有利于提高污泥的聚集度;②动力学选择、扩散限制理论对聚集度的影响受微生物聚集体大小的控制;③细胞存储能力的评估及其对聚集度的影响需要综合考虑PHB、聚磷和糖原的影响.另外,还提出了在污泥膨胀的控制中不一定要以抑制丝状菌的增殖作为控制目标,通过对丝状菌的颗粒化过程的探讨,进一步证实了污泥膨胀的控制与污泥聚集度的提高是相似的.本文提出的聚集度概念目前仍不成熟,尚无定量的描述方法,还需要进一步的研究.

Analysis of the factors that influence the aggregation-degree of microbial aggregates in sludge

A concept of sludge aggregation-degree is proposed, which includes two aspect definitions: one is the physical densification of sludge and the other is the aggregation of microbial species. Using bulking, flocculant and granular sludge as three typical aggregates and with reference to available bulking sludge control theories as well as the aerobic granulation conditions, the effects that influence the sludge aggregation-degree are discussed: ① a high level of substratc gradient, oxygen concentration and complex organic matter are beneficial for the increase of aggregation-degree; ② the effect of kinetic and diffusion limitation selections on aggregation-degree is controlled by the size of aggregates; and ③ the evaluation of storage capacity and its effect on aggregation-degree should take PHB, poly-P and glycogen into account. In addition, it is suggested that inhibition of the proliferation of filamentous bacteria is not necessary for control of sludge bulking, and based on the observation of granulation from filamentous sludge, controls of sludge bulking and increase of the aggregation-degree are similar. However, the aggregation-degree proposed in this paper is still immature and not quantitative,so further investigations are necessary.