用pH值强化以NO2-为电子受体的反硝化除磷效能

Utilization of p H to Enhance Denitrifying Dephosphatation with Nitrite as Electron Acceptor

由于NO2^-的抑制作用及对污水生物除磷具有潜在的危害,利用pH值操作因子对以NO2^-为电子受体的反硝化除磷系统进行优化。结果表明,NO2^-代替NO3^-会引起SBRn3运行性能的退化,但其在厌氧段pH值提升(从7. 0±0. 5升高至7. 8±0. 5)后又获得了一定的恢复,如厌氧释磷量、缺氧吸磷效率等。受限于NO2^-较低的产能系数及特定反硝化聚磷菌(DPAO)的流失,经强化的短程反硝化除磷系统虽可趋近于经典的厌氧生化模式,但仍呈现反硝化聚磷菌/聚糖菌(DPAO/GAO)混合代谢特征,这也被关联于pH值的ΔPO4^3-/ΔHAc计量学系数证实。菌群数量估算结果表明,微碱性pH值的控制策略能促进DPAO同时限制GAO的生长。

In view of the inhibitory effect of NO2^- and its potential harm to biological phosphorus removal from wastewater,pH was employed as a controller to optimize the denitrifying dephosphatation system with NO2^- as electron acceptor. The results showed that the performance of SBRn3 was degraded by replacing NO3^- with NO2^-. However,the performance recovered to some extent after the increase of pH value in the anaerobic stage (from 7. 0 ± 0. 5 to 7. 8 ± 0. 5),such as anaerobic phosphorus release and anoxic phosphorus uptake,etc. Limited by the lower energy production of NO2^- and the loss of specific denitrifying phosphate accumulating organisms (DPAO), the enhanced partial denitrifying dephosphatation system was close to classic anaerobic biochemical mode. However,it still performed a mixed DPAO/glycogen accumulating organisms (GAO) metabolism, which could be verified by stiochoimetric coefficient of ΔPO4^3-/ΔHAc. The estimation of bacterial population showed that the control strategy of a slightly alkaline environment could promote DPAO and restrict GAO growth.