Tank-Type Biological Reactors

For reactors with free turbulent flow without dominant boundary layer flows or gas/hquid interfaces (due to rising gas bubbles) such as stirred reactors with bafQes, all used model particle systems and also many biological systems produce similar results, and it may therefore be assumed that these results are also applicable to other particle systems. For stirred tanks in particular, the stress produced by impellers of various types can be predicted with the aid of a geometrical function (Eq. (20)) derived from the results of the measurements. Impellers with a large blade area in relation to the tank dimensions produce less shear, because of their uniform power input, in contrast to small and especially axial-flow impellers, such as propellers, and all kinds of inclined-blade impellers. 

Fig. 9.3 Flow diagrams for using an MFC reactor as the biological treatment process. (A) A conventional treatment train with a downstream soiids contact tank, sludge recycle line, and clarifier. (B) Combined with a MBR using the MFC as a pretreatment method to provide power for the MBR reactor, in a third option, the MFC could become a type of MBR (not shown).

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