间歇梯度曝气下缩短SRT强化短程SNEDPR系统脱氮除磷

为了探究间歇梯度曝气下污泥龄对氨氧化菌（AOB）和亚硝酸盐氧化菌（NOB）的影响，研究短程硝化内源反硝化除磷系统对于处理低C/N比生活污水的优势作用，本文采用SBR反应器培养好氧颗粒污泥，实验进水采用实际生活污水.结果表明，在SRT由50 d逐渐降低至30 d过程中，比氨氧化速率由3.16 mg·（g·h）^-1增加至4.38 mg·（g·h）^-1，比亚硝酸盐氧化速率由3.4 mg·（g·h）^-1降为1.8 mg·（g·h）^-1左右，可知NOB活性降低约44%，从而使系统实现了短程硝化.当SRT为30 d时，由典型周期实验可知亚硝酸盐最大积累量可达6.93mg·L^-1.由于系统中污泥浓度随SRT的减少而略有降低，因此在反应进行至40 d左右时根据DO曲线采取降低曝气量的策略，最终SRT为30 d时系统出水COD浓度为40.76 mg·L^-1，TN浓度为12.4 mg·L^-1，TP浓度为0.31 mg·L^-1，强化了系统中C、N和P的同步去除，最终得到了稳定运行的短程硝化内源反硝化除磷系统.同时好氧颗粒污泥EPS含量与SRT呈现负相关性，蛋白质含量由污泥龄为50 d的66.7 mg·g^-1升为30 d的95.1mg·g^-1，多糖保持在12.1~17.2 mg·g^-1的范围内，说明SRT的降低对蛋白质含量的影响较多糖大，当SRT为30 d时，PN/PS值保持在6.2左右，好氧颗粒污泥在该条件下仍能保持较好的结构稳定性.

Shortening SRT of Intermittent Gradient Aeration to Realize Nitrogen and Phosphorus Removal in Short-range SNEDPR System

This study explored the effect of sludge retention time (SRT) on ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) under intermittent gradient aeration, as well as the effect of the short-range nitrification endogenous denitrification phosphorus removal system on the treatment of low C/N ratio domestic sewage. In this study, an SBR reactor was used to cultivate aerobic granular sludge, using actual domestic sewage as the influent substrate. As the SRT decreased from 50 d to 30 d, the specific ammonia oxidation rate increased from 3.16 mg·(g·h)^-1to 4.38 mg·(g·h)^-1, and the specific nitrite oxidation rate decreased from 3.4 mg·(g·h)^-1to 1.8 mg·(g·h)^-1. The activity of NOB decreased by about 44%, resulting in short-range nitrification within the system. With an SRT of 30 d, the maximum nitrite accumulation was 6.93 mg·L^-1. Because the reduced SRT led to a slight decrease in sludge concentration within the system, an aeration reduction strategy was adopted after 40 d, according to the DO curve. When the final SRT was 30 d, the effluent COD concentration was 40.76 mg·L^-1, the TN concentration was 12.4 mg·L^-1, the TP concentration was 0.31 mg·L^-1, and the simultaneous removal of C, N and P was realized. Thus, a stable short-range nitrification endogenous denitrification phosphorus removal system was finally obtained. At the same time, the EPS content of aerobic granular sludge was negatively correlated with SRT, the protein content increased from 66.7 mg·g^-1 to 95.1 mg·g^-1, and the polysaccharide content remained in the range of 12.1-17.2 mg·g^-1, indicating that the decreased SRT had a great effect on the protein content. With an SRT of 30 d, the PN/PS value was maintained at approximately 6.2, and the structural stability of aerobic granular sludge can be maintained under such conditions.