SBR工艺中反硝化除磷特性研究

在ＮＯ^-₃-N/COD为0.04、0.095、0.125和0.27条件下,采用SBR反应器研究了反硝化除磷的特性.试验表明,污染物与控制参数（pH、ORP、 DO）具有良好的相关性.在搅拌阶段,ORP可以指示是否发生了反硝化聚磷反应;在好氧阶段,上述3个参数都可以监测TN浓度的低谷（NAS point）,但是pH最为灵敏.在NAS point排放上清液,能提高反应器的效率和出水水质.在反硝化聚磷的过程中,反硝化聚磷菌（DPBs）首先快速将ＮＯ^-₃-N转化为某种中间产物,然后再将该产物逐渐转化为N₂.有机碳源对DPBs的除磷能力有较大影响,当ＮＯ^-₃-N/COD大于0.095时,随着比值的升高,DPBs除磷能力增强.结果表明,为取得良好的反硝化除磷效果,ＮＯ^-₃-N/COD应不低于0.125.

Characteristics of Denitrifying Phosphorus Removal by Sequencing Batch Reactor

The characteristics of denitrifying phosphorus removal were studied in a laboratory sequencing batch reactor (SBR) at NO3--N to COD ratio (NO3--N/COD) of 0.04, 0.095, 0.125 and 0.27, respectively. Experiments showed that the transformations of pollutants correlated well to control parameters (i.e. pH, ORP and DO). In blending phase, the reaction of denitrifying phosphorus removal could be indicated by ORP, and in oxidation phase a valley concentration of TN called NAS point could be monitored by all the three parameters, among which pH was the most sensitive parameter. Both reactor efficiency and effluent quality would be improved when supernatant was discharged at NAS point. In denitrifying phosphorus removal process, NO3--N was quickly transformed into intermediate products firstly and then gradually into N2 by denitrifying P-bacteria (DPBs). Carbon source had a significant influence on phosphorus removal capability of DPBs: when NO3--N/COD ratio was higher than 0.095, phosphorus removal capability of DPBs enhanced with the increase of the ratio. Results indicated that NO3--N/COD ratio should not be lower than 0.125 for a favorable denitrifying phosphorus removal effect.