pH对低温除磷微生物种群与聚磷菌代谢的影响

Influence of pH on Microbial Community Structure and Metabolic Characteristics of PAOs in Biological Phosphorus Removal at Low Temperature

在5°C条件下通过运行SBR生物除磷反应器和静态实验考察pH对低温生物除磷系统的影响。pH不仅影响生物除磷反应器的性能,而且也会影响生物除磷系统的微生物种群结构。在pH为6的条件下长期运行的生物除磷系统中聚糖菌大量存在;而在中性（pH=7）和弱碱性（pH=8）条件下,聚磷菌在活性污泥中占有优势地位。静态实验结果表明,当pH在6~8.5之间变化时,聚磷污泥的厌氧释磷能力随pH的升高而提高。pH在6~8之间变化时,乙酸吸收和PHB的合成能力随着pH升高而加强,当pH升高到8.5时,PHB合成能力下降,从而抑制了好氧段磷酸盐的吸收。pH为8时,生物除磷系统实现了充分的释磷和吸磷,并取得了最好的除磷效果。

Impacts of pH on biological phosphorus removal（BPR） at low temperature were investigated in SBR reactors and batch experiments operated at 5 ℃.It was proved that pH affected not only the performance,but also the microbial community structure of BPR system.Acidic condition of pH 6 favored the accumulation of glycogen accumulating organisms（GAOs）,while polyphosphate accumulating organisms（PAOs） take predominant roles at pH 7 and 8.Anaerobic acetate uptake and poly-β-hydroxybutyrate（PHB） formation capacity enhanced with pH increasing from 6 to 8.5.However as pH increased to 8.5,less PHB synthesized in anaerobic phase inhibited the uptake of orthophosphate in aerobic phase.Highest phosphorus removal efficiency was obtained in batch tests at pH 8 accompany with the maximum amount of phosphorus released and uptaken.