Final Design
Considering the need for recirculation following the preliminary modeling process, the team recalculated the following parameters.
| Parameter | Calculated Value | Units |
|---|---|---|
| Hydraulic Retention Time | .62 | days |
| Limiting Substrate Concentration | .27 | mg BOD/L |
| Organism Washout Solids Retention Time | 1.35 | days |
| Limiting Solids Retention Time | 1.35 | days |
| Solids Retention Time | 6.75 | days |
| Safety Factor | 5.00 |
Final Design Parameters
The hydraulic retention time and safety factor were both raised to ensure that the microbes would have plenty of reaction time with the water and that the design would be operable under any condition. The limiting solids retention time was lowered to ensure that the solids retention time was well above the limiting. The limiting substrate concentration was raised, but still remains far less than the influent susbtrate concentration. After the parameters were set and checked, the team worked on the following mass balance figure to find flow rates and biomass concentrations at each stage of the process.
Final Design Mass Balance