水力停留时间对生物膜/颗粒污泥耦合工艺脱氮除磷的影响

采用自主设计的悬浮载体生物膜/颗粒污泥耦合装置，利用硝化菌载体生物膜和反硝化聚磷菌颗粒污泥，研究水力停留时间对生物膜/颗粒污泥耦合工艺脱氮除磷的影响，得出最佳工艺参数。试验考查水力停留时间分别为6 h、7 h、8.5 h和10.5 h，结果表明，当水力停留时间为8.5 h时，系统的COD去除率为91.26%，氨氮和总氮的去除率分别为80.68%和70.58%，厌氧释磷速率也较稳定，为0.47 mg P·（g SS）^-1·h^-1，厌氧释磷速率最高，其碳源利用率最大，反硝化除磷效率最稳定，PO₄^3--P去除率为76.50%，反硝化除磷效率为1.04 mg P·（mg NO₃^--N）^-1，所以当水力停留时间为8.5 h时，系统具有较高的脱氮除磷效率。当水力停留时间过短时，氮磷的去除不完全，过长时，系统不稳定，系统的最优水力停留时间为8.5 h。

Effect of hydraulic retention time on nitrogen and phosphorus removal by biofilm and granular coupling process

In home-designed coupling unit consisting of suspended carrier biofilm and granular sludge, biofilm supported nitrifying bacteria and denitrifying phosphorus granular sludge were used for investigating the effect of the hydraulic retention time (HRT) on nitrogen and phosphorus removal to arrive at optimizing process parameters. In the experiment, HRT was set at 6 h, 7 h, 8.5 h and 10.5 h. The results showed that when HRT was 8.5 h, the removal rates of COD, ammonia nitrogen and total nitrogen were 91.26%, 80.68% and 70.58% respectively. The release rate of phosphorus was 0.47 mg P·(g SS)^-1·h^-1, anaerobic phosphorus release and carbon source utilization were both at the highest rate, PO₄^3--P removal rate 76.50%, denitrifying phosphorus removal efficiency 1.04 mg P·(mg NO₃^--N)^-1. At the hydraulic retention time 8.5 h, the system had higher nitrogen and phosphorus removal efficiency. When the HRT was too short, nitrogen and phosphorus removal was incomplete, If too long, the system was unstable. Therefore, the system's optimal hydraulic retention time was 8.5 h.