GPS-X Technical Reference

Digestion Models 278
The resulting rate equation is:
Equation 10.2
where:
ftmum
mumh
ks
kia, kin
= the temperature correction factor for the growth of
methanogens
= maximum specific growth rate for methanogens
= the half-saturation coefficient
= the inhibition constants for slfn and snh, respectively
As in other biological models, the rate of decay of methane producing bacteria (r3) is
assumed to be proportional to their concentration:
Equation 10.3
where:
kd
= the decay rate coefficient
The effect of toxic substances (stox, input as a special component to the influent
parameters) is taken into account by using a first order expression for the rate of
inactivation of methane bacteria:
Equation 10.4
where:
ktox
= the inactivation rate coefficient
GPS-X Technical Reference