GPS-X Technical Reference

Suspended Growth Models 178
Facultative Ponds
The approach for facultative ponds is similar to that for anaerobic ponds, but uses a
different model for BOD reduction, and a slightly different approach for determining
state variable concentrations. The empirical BOD removal model used for facultative
ponds is from Thirumurthi (1974):
Equation 6.51
where:
BOD EFF = effluent BOD (g/m 3 )
BOD INF = influent BOD (g/m 3 )
K S = first order BOD removal rate coefficient (1/d) at 20°C
and
C TEMP
C O
= correction factor for temperature
= correction factor for organic loading
Equation 6.52
Equation 6.53
where:
TEMP = temperature, °C
θ
SLR
LR
= temperature correction constant
= standard loading rate (kg/ha/d)
= current loading rate (kgBOD/ha/d)
GPS-X Technical Reference