GPS-X Technical Reference

Suspended Growth Models 162
The intrinsic membrane resistance, R m, is provided in the
Input Parameters > Physical – Membrane form. The default value used is based on
data provided by Chang et al. (1999). In advanced mode, GPS-X tracks the formation of
a cake layer on the surface of the membrane that resists the liquid flux across the
membrane. The cake layer is assumed to be homogeneous and its thickness is calculated
as shown below in Equation 6.45 (Choi et al., 2000).
Equation 6.45
where:
δ c
m p
= cake layer thickness (m)
= dry mass of cake layer (kg)
p P = density of a cake layer particle (kg/m 3 )
ε
= porosity of cake layer (dimensionless)
A m = total membrane surface area (m 2 )
The dry mass of the cake layer (see Equation 6.44) is calculated using the following
dynamic mass balance on the cake layer:
Equation 6.46
GPS-X Technical Reference