Modeling of the Selected Alternatives

The selected alternatives including the anaerobic CSTR, trickling filter, and upflow anaerobic sludge balnket were modeled in Excel using various parameter equations. Tables displaying the calculated values are shown below.

Anaerobic Alternatives Modeling Results

The table above shows the calcualted values for both the anaerobic CSTR and upflow anaerobic sludge blanket since both technologies are modeled anaerobically. The minimum required HRT for a project is .208 days, so the calculated HRT was good for our project. The minimum required solids residence time was only slightly lower than the actual solids residence time, so that parameter needed to be lowered. To do so, recirculation was required to provide the chosen alternative system ample microbes to reduce the solids residence time. The minimum required substrate is very low compared to the approximate 21,075 mg/L of BOD entering the system which means an anaerobic system will work for our project. However, since the design requires recirculation, the upflow anaerobic sludge blanket was determined unfeasible since the design cannot sustain a high inflow rate.

Trickling Filter Modeling Results

As can be seen from the table above, the calculated values for each parameter either fall below or exceed typical values. Hydraulic loading was very low compared to its typical value for a high-rate trickling filter. Calculated surface and volumetric loading rates were very high compared to their typical values. Therefore, it was determined that a trickling filter would not be moved forward with.

Since the upflow anaerobic sludge blanket and trickling filter were deemed impractical for our project, they were not moved forward with. Therefore, the anaerobic CSTR was selected as the preferred alternative by default.