二级曝气生物滤池中碳、氮代谢特性的研究

Carbon and Nitrogen Metabolic Characteristics in Two-stage Biological Aerated Filter

采用以高分子生物载体为填料的二级曝气生物滤池处理生活污水,研究了进水有机负荷和NH3-N负荷对系统处理效果的影响。结果表明,在水温为18～25℃、pH值为5.8～7.4、气水比为3.5∶1时,对COD的去除率与进水有机负荷呈正相关,硝化率同有机负荷及NH3-N负荷呈负相关,且主要取决于前者。当有机负荷为2.75～3.90 kg/(m3.d)时,对COD的去除率可高达98%;当有机负荷为0.77～1.48 kg/(m3.d)时,硝化率可达93.3%～98.1%,对TN的平均去除率达39.4%。降低进水有机负荷可解除高负荷所导致的硝化抑制作用,使硝化的起始点提前,提高硝化率,显示出单独驯化的硝化滤池在去除NH3-N上的优势。硝化菌受反冲洗的影响大于异养菌,反冲洗6 h后系统可基本恢复对COD和NH3-N的去除效果。

A two-stage biological aerated filter system with biopolymer carrier as its filler was used to treat domestic sewage, and the influence of influent organic loading and ammonia nitrogen loading on the system treatment efficiency was studied. The results show that when the temperature is 18 to 25 ℃, pH is 5.8 to 7.4 and air/water ratio is 3.5 ： 1, there is a positive correlation between COD removal rate and influent organic loading, and the nitrification rate has negative correlations with both organic loading and ammonia nitrogen loading, the former plays the main role. COD removal rate attains 98% with 2.75 to 3.90 kgCOD/（m^3 · d）, while the nitrification rate achieves 93.3% to 98.1%, and the average removal rate of TN attains 39.4% with 0.77 to 1.48 kgCOD/（ m^3 · d）. Nitrification will start earlier to improve its efficiency when the influent organic loading reduces. The filter which is domesticated separately shows its advantage in ammonia nitrogen removal. The nitrification bacteria suffers a more serious impact from backwash than the heterotrophic bacteria, while the removal efficiencies of COD and ammonia nitrogen can be almost recovered after 6 h of backwash.