UASB反应器中颗粒污泥的沉降性能与终端沉降速度

The settling characteristics and terminal velocity of granular sludge in UASB reactor

从流体力学角度,通过建立沉降速度模型探讨了UASB反应器中颗粒污泥的沉降性能与终端沉降速度.计算结果表明,(1)绝大多数颗粒污泥的沉降过程属于过渡区(1<Re<100)而非层流区,其沉降速度与直径成正比,可用Allen公式进行计算;(2)颗粒污泥的终端沉降速度远高于厌氧反应器中废水的上流速度,其良好的沉降性能解决了在高负荷情况下污泥的流失问题.所建模型能较好地反映实际条件下的情况,为厌氧反应器的工艺设计与正常运行提供理论依据.

Due to the excellent settling properties of granular sludge, UASB reactors are widely used in wastewater treatment.The settling characteristics and terminal velocity of granular sludge in UASB reactors was discussed by using a terminal velocity model on the view of hydrodynamics. The results showed that: (1) the settling process of the most granular sludge was in the category of intermediate flow regime (1<Re<100)rather than in laminar flow one, the settling velocity of which was in proportion to the granular diameter and in accordance with Allen formula; (2) the terminal settling velocity was much greater than that of the liquid upflow, which successfully solved the problem of sludge wash-out under high organic loading rate (OLR). The validity of this model was verified by using the operating parameters of several anaerobic reactors in the practice. Furthermore, it could be a theoretical theory appling as a useful tool for the design and the operation of the high-rate anaerobic reactors