GPS-X Technical Reference

197 Suspended Growth Models
Oxygen Mass Transfer Coefficient at Field Conditions Calculations
GPS-X provides four different ways to specify the user inputs to estimate gas-liquid
transfer in the open basin HPO system.
1. Direct specification of the clean water at K La at 20°C
2. Specifying the gas flow rate at standard condition of 1 atm pressure and 20°C
temperature
3. Specify the wire point input of the oxygenator
4. Use a DO controller
In each of the above, the user has the option of specifying SOTE. The default value for
SOTE for high purity oxygen is considered to be 90%.
Entering KLa Directly
Estimate K La at field conditions
The KLa at field conditions is calculated using Equation 6.11:
Equation 6.11
where:
K La T
= mass transfer coefficient at temperature T in °C (1/day)
K La 20 = mass transfer coefficient at 20°C
θ
= temperature correction factor (default value
GPS-X is 1.024)
α = wastewater correction factor for K La 20
F =diffuser fouling factor (default value in GPS-X is 1.0)
T
= wastewater temperature (°C)
GPS-X Technical Reference