Available at: https://digitalcommons.calpoly.edu/theses/2731
Date of Award
12-2023
Degree Name
MS in Civil and Environmental Engineering
Department/Program
Civil and Environmental Engineering
College
College of Engineering
Advisor
Trygve Lundquist
Advisor Department
Civil and Environmental Engineering
Advisor College
College of Engineering
Abstract
Microalgae biomass has potential as a feedstock for various bioproducts, including biofuel. Algae can be cultivated on treated wastewater or on untreated wastewater, accomplishing treatment as a co-benefit. Greater understanding of algal productivity is needed. This study compared the net productivity of naturally forming algae polycultures, and monocultures of Scenedesmus obliquus (DOE0152Z) and Tribonema minus cultivated on treated municipal wastewater or primary clarifier effluent. The experiments were conducted in outdoor, 1350-L and 1000-L, raceway tanks in coastal central California during a multi-year period. A linear regression model of net productivity (i.e., based on the difference of biomass in the influent and effluent of the raceways) was developed. The highest productivity culture was a polyculture grown on primary clarifier effluent at 20.0 +/- 3.8 g/m2-day (ash-free dry weight, AFDW over 12 months of continuous cultivation). The monoculture with the highest productivity was Tribonema minus at 16.1 +/- 0.8 g/m2-day (summer through winter). In the various strain and wastewater type combinations tested, solar radiation was the most statistically significant predictor of net productivity (p