Kinetics
All substrate uptake rates were established as shown in equation (A-1):
\begin{equation}
\frac{dC_{j}}{\text{dt}}=q_{j}X_{\text{lumped}}\ \left(A-1\right)\nonumber \\
\end{equation}- Cj = concentration of compound J
[gCOD·L-1]
- qj = the subsrate specific uptake rate for compound j
[gCODj·gVSS-1·h-1]
- Xlumped = the lumped amount of biomass present in the
reactor
In this study the biomass was lumped as total VSS minus the storage
polymer solids present in the reactor. It was not feasible to obtain
fractions of biomass (species differentiation) from the total amount of
VSS and thus it was not possible in obtaining specific activities.
Therefore, the activities rather represent the activity of the total
amount of catalytic VSS present in the reactor. The substrate kinetics
equations for glucose, storage polymer (SP) and lactate consumption are
shown in table A.2. For the consumption of the storage polymer a
shrinken particle model was used. Furthermore, it was assumed that the
consumption of the storage polymer started after all extracellular
glucose was consumed. For the model the starting amount of SP was set to
1 gCOD and the final value (end of the cycle) was set to be 1 ± 0.05
gCOD.
Table A.2. The kinetic equations used in the study to calibrate the
measured data. Ks,Glu is the half-saturation constant
for glucose, Ks,lac is the half-saturation constant for
Lactate