摘要
应用FISH对以乙酸钠为碳源的强化生物除磷(EBPR)SBR反应器启动期的微生物进行原位分析,考察除磷生态系统形成过程中聚磷菌种群结构、空间分布关系动态变化及其聚磷特性.结果表明,以异养菌为主的活性污泥经过厌氧/好氧驯化后,聚磷菌大量富集,在全菌中的比例由11.5%增加到40.48%.启动过程中,生物系统内菌群竞争持续进行:首先,聚磷菌淘汰异养菌,历时5 d;聚磷菌种群内选择过程历时19 d;经过优势聚磷菌群的二次增长后,共计34 d完成生物除磷系统的启动.富集过程中快速增殖的聚磷菌不能立刻行使除磷能力,要有一段"积累期"形成一定的PHA和poly-P储备.表现为污染物去除效率滞后于聚磷菌的增殖,经过4～8 d的"积累期"后上升出现峰值.二次增长的优势聚磷菌群也经过"积累期"后才发挥作用.FISH图片显示,快速增殖期的聚磷菌菌体小,菌群结构松散.经过"积累期"之后,菌体不断增大,并开始紧密聚集形成致密的团状,此时反应器处理效率较高.
Enhanced biological phosphorus removal （EBPR） process was operated in a laboratory-scale sequencing batch reactor （SBR） for one-month fed with acetate as the carbon source. The characteristic and the microbial population structure and space distribution dynamics of phosphate-accumulating organisms （PAOs） of start-up period were analyzed by fluorescent in situ hybridization （FISH）. The relationship between enrichment of PAOs and phosphorus removal was discussed. PAOs could be enriched by recirculation activated sludge containing heterotrophs through anaerobic aerobic conditions. Portion of PAOs in the sludge increase from 11.5 % to 40.48%. Bacteria population competition lasted 34 days. It started from PAOs replacing heterotrophs which cost 5 days then followed by 19 days intra-spocifie competition of PAOs. The last step was re-increasing of PAOs predominance. Phosphorus uptake by the enriched microbial community was not observed immediately. An accumulating-phase was necessary for PHA and poly-P storage. A lag-stage of 4-8 days existed when taking the performance of the reactor into consideration. Phosphorus removal by the predominant PAOs through intra-speeific competition was achieved after accumulating-phase too. The FISH picture indicated that in the quickly growing phase PAOs cells were small and community structure was loose. The latter ＂accumulating-phase＂ cells became larger and the community structure clustered densely. This stage presented by better reactor performance.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2009年第1期80-84,共5页
Environmental Science
基金
国家自然科学基金项目(50508011)
