容积分配比对A2/O-生物接触氧化工艺反硝化除磷特性的影响

Effect on denitrifying phosphorus removal by optimizing volume ratios in A2 / O-biological contact oxidation( A2 / O-BCO) process

提出了一种新型的A2/O-生物接触氧化（A2/O-BCO）双污泥系统.该工艺通过在A2/O反应器中充分利用原水碳源,以BCO反应器完成硝化的NO-x-N为电子受体,实现稳定高效的反硝化除磷.考察了实际生活污水在A2/O反应器中不同容积分配比（厌氧/缺氧/好氧）对A2/O-BCO系统反硝化除磷特性的影响.结果表明：系统对有机物的去除具有较好的稳定性,且容积比的变化对COD的去除率影响不大;当容积比为2∶4∶1时,系统达到了较高的脱氮除磷效果,出水的TN和PO3-4-P浓度分别为13.41和0.28 mg/L.通过氮平衡分析发现,BCO反应器存在同步硝化反硝化现象,同时厌氧氨氧化的发生也促进了氮损失.此外,A2/O反应器的好氧区对稳定出水PO3-4-P浓度发挥着重要作用,为了防止二次释磷,中间沉淀池的NO-x-N浓度应控制在1.95～2.75 mg/L.

A novel two-sludge process of A2 / O-biological contact oxidation（ A2 / O-BCO） is proposed. Stable and efficient denitrifying phosphorus removal can be realized by high-efficiency utilization of influent carbon sources in the A2 / O reactor with the electron acceptors of NO-x-N in the BCO reactor. The denitrifying phosphorus removal characteristics of the A2 / O reactor under different volume ratios（ anaerobic zone / anoxic zone / aerobic zone） with real domestic wastewater were investigated. The results showthat the system exhibits good stability for organic matter removal,and the variation of the volume ratios has little effect on COD（ chemical oxygen demand） removal.When the volume ratio is 2∶ 4∶ 1,the effect of nitrogen and phosphorus removal is high,the effluent TN and PO3-4-P concentrations being 13. 41 and 0. 28 mg / L respectively. The nitrogen balance analysis results showthat the phenomenon of simultaneous nitrification denitrification（ SND） exhibits in the BCO reactor,and the occurrence of anaerobic ammonia oxidation（ Annamox） contributes to the nitrogen loss. Additionally,the aerobic zone of the A2 / O reactor plays an important role in keeping stable effluent PO3-4-P concentration. In order to prevent secondary phosphorus release,the NO-x-N concentration in the middle settler should be controlled to 1. 95 to 2. 75 mg / L.