高频间歇梯度曝气启动短程硝化反硝化除磷颗粒污泥

反硝化除磷与厌氧氨氧化耦合可进一步降低脱氮除磷所需的碳源，而稳定获取NO₂^--N是两工艺独立、联合运行的关键.因此，以低C/N生活污水为研究对象，接种絮状污泥及少量长期贮存的好氧颗粒污泥，采用两段梯度曝气，并控制停曝时间（3min：3min），即以高频间歇梯度曝气模式，经60d的富集培养，将其诱导成具有短程硝化反硝化除磷功能的颗粒污泥，并分析了此过程中系统脱氮除磷性能变化.结果表明，稳定时期内，颗粒污泥平均粒径达841μm，SVI为31.23ml/g，颗粒结构致密，沉降性能良好.出水NO₃^--N小于0.1mg/L，TP<0.7mg/L，NO₂^--N>15mg/L，实现了P的高效去除和NO₃^--N的积累，并可为后续耦合Anammox提供稳定NO₂^--N基质.批次实验结果表明，颗粒中可利用NO₂^--N为电子受体的DPAOs占达57.63%，其富集提高了系统除磷能力.高频梯度间歇曝气可实现AOB与DPAOs的高度耦合，但仅以间歇曝气难以实现NOB的抑制，后通过在"氨谷点"前段，加入梯度曝气优化实际限氧曝气点，可强化对NOB的抑制，从而实现良好的亚硝酸盐积累.

High frequency intermittent gradient aeration initiation of short-cut nitrification and denitrification for phosphorus removal of granular sludge

The coupling of denitrifying phosphorus removal and Anammox can further reduce the carbon source needed for nitrogen and phosphorus removal, and the stable production of NO₂^--N is the key to the independent and joint operation of the two processes. Therefore, with low C/N domestic sewage as the research object, flocculent sludge and a small amount of long-term stored aerobic granular sludge were inoculated in the reactor. The short-cut nitrification-denitrification-dephosphorization granular sludge was cultivated in 60 days by two-stage gradient aeration with the stop aeration time (3min:3min) controlled, and the system denitrification and dephosphorization performance was analyzed in this process. The results show that the average particle size of granular sludge is 841μm and the SVI is 31.23ml/g during the stable period. The particle structure is compact and the settling performance is good. The effluent NO₃^--N was less than 0.1mg/L, TP was less than 0.7mg/L, NO₂^--N was more than 15mg/L, which realized the efficient removal of P and accumulation of NO₂^--N, and could provide a stable NO₂^--N substrate for subsequent coupling of Anammox. The results of batch experiments showed that 57.63% of the DPAOs in the particles which could use NO₂^--N as electron acceptor, and the enrichment of DPAOs improved the phosphorus removal ability of the system. High-frequency intermittent gradient aeration can achieve a high coupling between AOB and DPAOS, but it is difficult to achieve NOB suppression only by intermittent aeration. Then, by adding gradient aeration in the front section of "ammonia trough point" to optimize the actual oxygen limiting aeration point, the inhibition of NOB can be enhanced, so as to achieve good accumulation of nitrite.