GPS-X Technical Reference

Digestion Models 294
UASB/EGSB MODEL
The UASB/EGSB model is available only in MANTIS2LIB. The Mantis2 model is used to model
the biological-chemical reactions in the reactor. Some of the assumptions made in the
development of model are listed below.
1. The hydraulic regime in the UASB/EGSB is modeled as completely mixed reactor.
2. The substrate diffusion into the granule is assumed to be not limiting and the
reactions are modeled similar to the suspended growth systems.
3. The average granule properties are used to estimate the granule settling velocity and
bed expansion in the reactor.
4. A semi-empirical model is used to estimate the solid concentration distribution above
the bed.
The simplified model structure is a first attempt to dynamically model the UASB//EGSB reactors
for practical engineering problems.
Some of the important inputs and outputs of the model are described in following sections.
Reactor Parameters
Additional sets of input parameters are required for the UASB/EGSB model to estimate
the granule settling velocity, bed fluidization and solid distribution profile above the
sludge bed.
The Reactor Parameters can be accessed from the Input Parameters menu item
(Figure 10-14). The Reactor Parameters form is as shown in Figure 10-15.
Figure 10-14 - Reactor Parameters for UASB/EGSB Reactor
GPS-X Technical Reference