Team:Rice/Model
MODELING
Wastewater Treatment Process
Wastewater initially has most of its suspended solids settled out in primary treatment and then it is sent to a process called secondary treatment where most of the organic solutes are removed from the water by aerobic bacteria. After secondary treatment, any remaining bacteria are killed in tertiary treatment and then the water is released. We decided to implement our engineered bacteria as a part of an activated sludge secondary treatment system because there is already an existing environment for bacteria, a system for biocontainment, and a method of disposal for the chromium our bacteria will absorb and reduce.
We used a differential equation model to evaluate the feasibility of our bacterium’s incorporation in an activated sludge system.
Our model takes into account the following processes:
- chromium transport
- chromium reduction
- induced cell death
- cellular respiration and growth
- bacterial sedimentation
- interspecies competition
- occasional sludge purging
The model is capable of considering temporal variation in chromium levels and rate of wastewater arrival as well as events like purging of excess sludge and seeding with our engineered bacteria. We are also able to predict the amount of our bacteria and chromium in the system’s output. We were also able to predict the efficacy of our chromium remediation.
Schematics of Modeled Processes
Early figure concepts designed to illustrate model behavior.
Differential Equations
Figures
