分段进水对A^2O/MBR组合工艺的影响机制研究

Influence Mechanism of Step-feed on Combined Process of A^2O and MBR

针对现有城市污水处理厂进水碳源不足的问题,根据厌氧释磷和反硝化脱氮对碳源的不同需求,采用分段进水A2O/MBR组合工艺,研究分段进水对其影响机制。结果表明:分段进水优化了进水碳源在厌氧池和缺氧池中的分布,对TN的去除率随分配到缺氧池流量的增加而增大。当缺氧池分配流量增加到0.35Q时,对总氮的平均去除率达到56.8%,较单点进水工况提高了14.0%。分段进水对去除COD的影响不大,对COD的去除率稳定在82.3%~85.7%。由于进水中溶解性磷浓度较低,磷主要以胶体态和悬浮态形式存在,通过超滤膜的截留作用,组合工艺对TP的平均去除率稳定在90%以上;不过采用分段进水后,组合工艺对TP的平均去除率会略有下降。

Aimed at the shortage of influent carbon source in municipal wastewater treatment plants, based on the different demands of carbon source for anaerobic phosphorus release and denitrifica- tion, the combined process of A^2O and MBR with step-feed was used. The influence mechanism of stepfeed on the combined process was investigated. The results show that the distribution of carbon source in anaerobic and anoxic zones is optimized by step-feed process, and the removal rate of TN is improved as the flow rate distribution in anoxie zone is increased. When the flow rate distribution in anoxic zone is up to 0.35Q, the average removal rate of TN reaches 56.8% , which is increased by 14.0% compared with a single point feed into the anaerobic zone only. COD removal is hardly affected by the step-feed process, and the removal rate is between 82.3% and 85.7%. Due to the low concentration of soluble phosphorus and the existence of phosphorus mainly in colloidal and suspended forms in the influent, TP is mainly removed by the uhrafihration membrane. The average removal rate of TP is above 90% , which is decreased slightly after the step-feed process.