Dynamic Behavior of a Bioreactor
Dynamic Behavior of a Bioreactor
The dynamic behavior of a chemostat can be described with the following system of ordinary differential equations:
dX
dt
dS
dt
-μX
Y
S
in
where is the dilution rate in , is the biomass concentration in g/l, is the substrate concentration in g/l, is the feed substrate concentration, is the yield, and is the specific growth rate given by the Monod function: , where is the half saturation constant and is the maximum value of the specific growth rate (=1 here).
D
-1
s
X
S
S
in
Y=
dX
dS
μ
μ=S+S
μ
max
K
S
K
S
μ
max
μ
max
This Demonstration lets you plot the substrate and biomass concentrations versus time and observe the washout (a phenomenon that occurs when the dilution rate, , is so large that all micro-organisms will end up exiting the bioreactor). Another snapshot shows a situation where the biomass in the reactor reaches a steady-state value different from zero.
D