Graduation Year


Document Type




Degree Granting Department

Civil and Environmental Engineering

Major Professor

Daniel Yeh, Ph.D.

Committee Member

Piet Lens, Ph.D.

Committee Member

Qiong Zhang, Ph.D.


mass balance, carbon dioxide, algae economics, nitrogen, phosphorous, Monod kinetics


Based on a municipal wastewater treatment plant (WWTP) in Tampa, FL, a dynamic multiple-systems model was developed on the STELLA software platform to explore algae biomass production in wastewater by incorporating two photobioreactors into the WWTP‟s treatment train. Using a mass balance approach, the model examined the synergy through algal growth and substrate removal kinetics, as well as macroeconomic-level analyses of algal biomass conversion to biodiesel, biogas, or fertilizer. A sensitivity analysis showed that biomass production is highly dependent on Monod variables and harvesting regime, and profitability was sensitive to processing costs, market prices of products, and energy environment. The model demonstrated that adequate nutrients and carbon dioxide are available in the plant‟s influent to sustain algal growth. Biogas and fertilizer production were found to be profitable, but biodiesel was not, due to high processing costs under current technologies. Useful in determining the growth potential on a macro-level, the model is a tool for identifying focus areas for bench and pilot scale testing.