水力停留时间对曝气生物滤池处理效能及运行特性的影响

通过实验室模型试验研究了曝气生物滤池处理模拟生活污水的效能，分析了水力停留时间(HRT)变化对曝气生物滤池处理效果及运行特性的影响规律。研究发现，当HRT大于0.6h时，曝气生物滤池具有良好的有机物和浊度的去除效果，而当HRT为0．4h时，处理效果则显著下降；反应器的硝化反硝化脱氮能力受HRT的影响比较明显，缩短HRT将使氨氮和总氮去除率迅速下降，当HRT为1.25h时，氨氮和总氮去除率分别达到70%和40％以上；缩短HRT会在一定程度上促进亚硝酸盐积累现象的发生。而反应器的过滤周期则与HRT呈明显的线性关系。

Effect of hydraulic retention time on the treatment efficiency and operational characteristics of biological aerated filter

A bench-scale investigation was accomplished to evaluate the effect of hydraulic retention time (HRT) on the efficiency and operational characteristics of biological aerated filter (BAF) by using a synthetic domestic wastewater as feed water. The variations of operation pattern and treatment efficiency of the bioreactor resulted from the changing of hydraulic retention time were analyzed. The experimental results demonstrated that it was effective to remove the organic matters and turbidity when the hydraulic retention time was longer than 0.6 h. However, the removal efficiency of organic matters and turbidity decreased remarkably when the hydraulic retention time was 0.4 h. The nitrification and denitrification ability of BAF declined sharply with decreasing the hydraulic retention time. The ammonia and total nitrogen removal efficiency were more than 70% and 40% respectively when hydraulic retention time was longer than 1.25 h. In addition, it was also observed that nitrite accumulation could be carried out when the hydraulic retention time was shortened, and that a linear relationship between hydraulic retention time and operation time was also found in the study.