低温强化生物除磷反应器中微生物的竞争关系

Competition between phosphate-accumulating organisms and glycogen-accumulating organisms and the phosphate removal efficiency in EBPR reactor at low temperature

摘要:

为了考察低温条件下聚磷菌和聚糖菌之间的竞争关系及其对反应器除磷效果的影响,利用FISH技术跟踪检测了低温条件下运行的强化生物除磷(EBPR)SBR反应器中的聚磷菌和聚糖菌.实验结果表明,0～20d为调整阶段,反应器的各项指标不稳定,聚磷菌和聚糖菌在反应器中竞争优势地位.从菌体数量曲线发现,调整阶段中,聚磷菌数量逐渐增加,而Alphaproteobacteria数量逐渐减少,Gammaproteobacteria数量低于8.11%.这种现象说明低温更有利于聚磷菌的生长繁殖,使其在反应器中占据优势地位,并淘汰聚糖菌.50～60d聚磷菌快速增殖,由于聚磷菌的数量5d内只增加了3.2%,没有造成反应器处理效果的延迟现象.

Abstract:

Enhanced biological phosphorus removal (EBPR) was operated in a laboratory-scale sequencing batch reactor (SBR). Fluorenscent in situ hybridization (FISH) was used to study the competition between the phosphate-accumulating organisms (PAOs) and glycogen-accumulating organisms (GAOs). The influence of competition between PAOs and GAOs on phosphate removal efficiency was discussed. The results showed that 0-20 d was an adjusting stage. COD and phosphate removal efficiencies of SBR were unstable. PAOs and GAOs competed for the predominant status in reactor. During 20-60 d,the amount of PAOs increased gradually,while the amount of Alphaproteobacteria decreased and Gammaproteobacteria contents was below 8. 11% in this stage,which indicates that low temperature is beneficial to PAOs. PAOs proliferated rapidly during 50-60 d. Because the increased amount of PAOs was only 3. 2% per 5 d,the phosphate removal efficiency in reactor was not delayed.