长/短HRT联合低/高曝气实现短程硝化反硝化脱氮除磷

为了实现从同步硝化反硝化除磷向短程硝化反硝化除磷颗粒的转变，以颗粒污泥为接种污泥，采用低C/N比的人工配水，通过长/短HRT下的低/高曝气强度交替策略驯化短程硝化反硝化除磷系统。本策略能够维持更高的游离亚硝酸（FNA）浓度和持续时间，在抑制好氧聚磷菌的同时富集反硝化聚磷菌（denitrifying phosphate accumulating organisms, DPAOs）；此外，利用氨氧化菌与亚硝酸盐氧化菌（nitrite oxidizing bacteria, NOB）的亲氧能力差异产生亚氮积累，为DPAOs提供电子受体，最终实现短程硝化反硝化除磷。结果表明，第60天时采用低/高曝气策略的颗粒污泥中\mathrm{N}{\mathrm{O}}_{\mathrm{2}}^{-}型DPAOs占比达45%，NOB 活性下降至3.28mgN/(gMLVSS·h)。在处理低碳源污水时，低/高曝气强度模式相较于恒定曝气强度模式展现出了更强的适应性和稳定性。稳定期出水COD浓度在50mg/L以下，出水总氮（TN）和总磷（TP）浓度分别低于15mg/L和0.5mg/L，TN去除率达94.54%，TP平均去除率为96.90%。

Achieving shortcut nitrification and denitrification phosphorus removal relies on long/short HRT combined with a low/high aeration strategy

In order to realize simultaneous nitrification and denitrification phosphorus removal turn to short-cut nitrification and denitrification phosphorus removal, taking the particles as the inoculated sludge, the granular sludge was domesticated by using the artificial water distribution with low C/N ratio and the alternating strategy of low/high aeration intensity under long or short hydraulic retention time (HRT). This strategy could maintain higher FNA concentration and duration, inhibit phosphate accumulating organisms (PAOs) and enrich denitrifying phosphate accumulating organisms (DPAOs) at the same time. In addition, the difference of oxygen affinity between AOB and NOB was used to produce nitrous accumulation, providing electron acceptor for DPAOs, and finally, realize shortcut nitrification and denitrification phosphorus removal. The results showed that the proportion of \mathrm{N}{\mathrm{O}}_{\mathrm{2}}^{-}-DPAOs in granular sludge with low/high aeration strategy was 45% and the activity of NOB decreased to 3.28mgN/(gMLVSS·h) on the 60th day. In the treatment of low-carbon source wastewater, the low/high aeration intensity mode showed stronger adaptability and stability than the constant aeration intensity mode. In the stable period, the effluent COD concentration was less than 50mg/L, the effluent TN and total phosphorus (TP) concentrations were less than 15mg/L and 0.5mg/L, respectively. The TN removal rate was 94.54% and the average TP removal rate was 96.90%.