生物除磷系统聚糖菌的代谢机理及菌群结构

针对聚糖菌的富集引起强化生物除磷系统(EBPR)运行不稳定问题,开展聚糖菌代谢机理、微生物形态和菌群结构研究,以了解EBPR工艺的微生物原理.聚糖菌在厌氧环境中分解体内的糖原以获得能量来摄取外界环境中的短链脂肪酸,因而在厌氧反应阶段与聚磷菌形成对有机底物的竞争矛盾.尤其当聚糖菌在某些未明确因素下取得竞争优势后,系统中的聚磷菌将逐渐被淘汰替换或成为非优势菌种,从而导致EBPR除磷功能的完全丧失.研究表明,进水基质类型、进水P/C比、pH、温度以及亚硝酸盐等因素决定着聚糖菌和聚磷菌的竞争优势,并在特定阈值内引起EBPR系统聚糖菌的富集而使除磷功能丧失.

Metabolic mechanism and microbial community of glucose accumulating organisms (GAOs) in enhanced biological phosphorus removal processes

The overgrowth of the glycogen accumulating organisms(GAOs) has become one of the main reasons causing the unsteady operation of enhanced phosphorus removal(EBPR) processes.Therefore,the metabolic mechanism of GAOs as well as their microbial morphology and community is introduced for better understanding the exact microbial community of EBPR.GAOs can use synthetic glycogen as the energy source to assimilate volatile fatty acids(VAFs) anaerobically,resulting in a competition with phosphorus accumulation organisms(PAOs) for VAFs.Also,they will become the dominate population under un-identified conditions by outcompeting PAOs,ultimately leading to the failure of EBPR.The studies show that the influent organic composition,P/C,pH,temperature and nitrites are the key factors impacting the competition between PAOs and GAOs.Within the certain ranges of the above operational parameters,the accumulation of GAOs occurs and the PAOs activities will be completely inhibited.