上向流曝气生物滤池水头损失沿程分布与动态特性

Headloss profile and dynamic characteristics in upflow biological aerated filter

对比考察了天然斜发沸石、页岩陶粒和石灰岩碎石填料曝气生物滤池的水头损失增长规律,分析了3种滤池水头损失的空间分布特征和动态变化特性,探讨了截留固体累积量对水头损失发展的影响规律。结果表明,沸石、陶粒和石灰岩曝气生物滤池均具有较好的有机物和SS沿程去除能力,并与水头损失的沿程分布密切相关;滤池内部TSS的沿程变化趋势和水头损失沿程分布趋势基本一致;曝气生物滤池的水头损失随着反应器运行时间的延长而缓慢增加,当滤床内TSS积累量增加到一定程度时,气体的滤床驻留率增加,并与TSS积累协同作用,滤床局部孔隙率迅速下降,水头损失迅速越升。曝气生物滤池的反冲洗首先应着眼于解决滤床的局部孔隙率过低问题,然后以气洗促进颗粒碰撞,气水联合提高剪切力,最后水漂洗排出TSS和气泡。

Headloss development in three biological aerated filters with zeolite,ceramic particle and carbonate,respectively,were investigated in this paper.The profile and dynamic characteristics of headloss development and the influence of solid accumulation on the headloss development were also considered.Promising COD and SS removal performance were observed in the three filters,and that were relevant to the headloss profile.The variation tendency of TSS in the filter was also in accord with that of headloss profile.The headloss in BAF increased slowly with filter operation.The gas holdup in the filter bed increased with TSS increasing and could accelerate the headloss development.When TSS increased to a certain extent,the gas holdup increased quickly,porosity ratio of filter bed decreased and headloss ascended suddenly.It was suggested that the backwashing of BAF should be carried out to recover bed porosity ratio in some location firstly.The gas washing could promote the collision of granular media,and then to enhance the shearing force by gas and water washing,finally rinsed with water to discharge TSS and gas.