Endogenous respiration coefficient

The constant kd is referred to as the endogenous respiration coefficient or the specific maintenance rate. Pirt(45) points out that kd is proportional to m, the maintenance coefficient defined in equation 5.51 ... 

A limitation of the methods described so far is that they have assumed a constant overall yield coefficient and do not allow the endogenous respiration coefficient kd (or alternatively the maintenance coefficient, m) to be evaluated. Equation 5.54 shows that the overall yield, as measured when monitoring a batch reactor, is affected by the growth rate and has the greatest impact when the growth rate is low. Consequently, it is desirable to be able to estimate the values of kd or m, so that the yield coefficient reflects the true growth yield. An equivalent method would be one where the specific rates of formation of biomass and consumption of substrate were determined independently, again without the assumption of a constant overall yield-coefficient. 

The steady-stale substrate and biomass concentrations for a continuous stirred-tank fermenter operated at various dilution rates are given below. Given that the fresh feed concentration is 700 mg/l, calculate the values of the Monod constants and Ks the yield coefficient, Y and the endogenous respiration coefficient kd. 

Kj = Endogenous respiration coefficient [day ]. A value of 0.08 being applicable. 

Here, V is the averaging volume and VB(t) is the volume of phase B within the averaging volume. The parameters sA and eB are the volume fractions of the phases A (eA = VA/V) and B (eB = VB/V), respectively. The parameter Dje is the effective diffusivity tensor of component Ji max e is the maximum reaction rate, and r/n is the first-order endogenous respiration rate coefficient. The cell mass per unit volume of biofilm is defined by... 

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