Monod plug flow

In the present study, the UASB reactor was modeled in terms of the dispersed plug flow and the Monod type of rate equations to constmct the differential mass balance equations fcs- the anaerobic biodegradation of single and multiple substrates components of the volatile fetty acids. 

A pilot scale UASB reactor was simulated by the dispersed plug flow model with Monod kinetic parameters for the hypothetical influent composition for the three VPA ccmiponents. As a result, the COD removal efflciency for the propionic acid is smallest because its decomposition rate is cptite slow compared with other substrate components their COD removal eflSciencies are in order as, acetic acid 0.765 > butyric acid 0.705 > propionic acid 0.138. And the estimated value of the total COD removal efficiency is 0.561. This means that flie inclusion of large amount of propionic acid will lead to a significant reduction in the total VFA removal efficiency. 

Figure 29.1 Behavior of batch or plug flow reactors for Monod type microbial fermentation.

It is awkward to try to evaluate the rate constants of the Monod equation from batch or plug flow data. Mixed flow data are so much simpler to interpret, as we shall see. 

EXAMPLE 29.2 PLUG FLOW REACTOR FOR MONOD KINETICS... 

Figure 6.36. Plot of the dimensionless concentration of cell mass x and substrate s for a continuous culture as a function of the dimensionless mean residence time I as in Fig. 6.1b with Xq > 0 Calculated comparison between a CSTR with maximum mixing (ST m) or one with total segregation (ST J and a continuous plug flow reactor (PF), assuming Monod kinetics with a death rate (Tsai et al., 1969).

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