3.1 Approach for Modeling of Fixed-Bed Hybrid Bioreactor
43
Fig. 3.2 Profile of substrate
concentration in a fixed
biofilm reactor (FBR)
Fig. 3.3 Profile of substrate concentration in a completely mixed biofilm reactor (CMBR)
of substrate concentration in a fixed biofilm reactor and completely mixed biofilm
reactor is shown in Figs. 3.2 and 3.3, respectively.
From Fig. 3.2, it is evident that entering substrate concentration S 0 in the bulk
liquid becomes entering substrate concentration S s and exiting substrate concentration S w at the biofilm–liquid interface due to diffusion in the stagnant liquid layer
attached to biofilm, and it further decreases to S min , i.e., the minimum substrate
concentration at biofilm attachment surface. The substrate flux which is varying over
the biofilm thickness can be averaged to account for the substrate mass balance. This
average flux must be same as that derived from the entering substrate concentration
S s and the exiting substrate concentration S w in the biofilm–liquid interface.
From Fig. 3.3, it is evident that entering substrate concentration S 0 becomes exiting
substrate concentration S w in the bulk liquid due to mechanical mixing in the reactor.
This concentration S w is the homogeneous bulk liquid concentration up to the liquid–
biofilm interface and which further decreases to S min , i.e., the minimum substrate
concentration at biofilm attachment surface. There is a variation in the substrate flux
over the biofilm thickness that can be averaged to account for the substrate mass
balance. This average flux must be same as that derived from the entering substrate
concentration S 0 and the exiting substrate concentration S w in the biofilm reactor. The
mathematical model for the biofilm growth essentially considered the substrate mass
43
Fig. 3.2 Profile of substrate
concentration in a fixed
biofilm reactor (FBR)
Fig. 3.3 Profile of substrate concentration in a completely mixed biofilm reactor (CMBR)
of substrate concentration in a fixed biofilm reactor and completely mixed biofilm
reactor is shown in Figs. 3.2 and 3.3, respectively.
From Fig. 3.2, it is evident that entering substrate concentration S 0 in the bulk
liquid becomes entering substrate concentration S s and exiting substrate concentration S w at the biofilm–liquid interface due to diffusion in the stagnant liquid layer
attached to biofilm, and it further decreases to S min , i.e., the minimum substrate
concentration at biofilm attachment surface. The substrate flux which is varying over
the biofilm thickness can be averaged to account for the substrate mass balance. This
average flux must be same as that derived from the entering substrate concentration
S s and the exiting substrate concentration S w in the biofilm–liquid interface.
From Fig. 3.3, it is evident that entering substrate concentration S 0 becomes exiting
substrate concentration S w in the bulk liquid due to mechanical mixing in the reactor.
This concentration S w is the homogeneous bulk liquid concentration up to the liquid–
biofilm interface and which further decreases to S min , i.e., the minimum substrate
concentration at biofilm attachment surface. There is a variation in the substrate flux
over the biofilm thickness that can be averaged to account for the substrate mass
balance. This average flux must be same as that derived from the entering substrate
concentration S 0 and the exiting substrate concentration S w in the biofilm reactor. The
mathematical model for the biofilm growth essentially considered the substrate mass