.4. Comparison with literature studies
Results of this study are compared in
Table 3 with those reported in the literature. While the reported studies have been
conducted with different algal species grown in different wastewa-ter sources, the comparison is made on the basis of BOD5 and nutrient removal rates. The ammonical nitrogen and phosphate
removal rates (15.5 and 3.6 mg L 1 d 1
respectively) found in this study are comparable to those reported in the literature. This com-
parison further supports the selection of G. sulphuraria as a ben-eficial strain for urban wastewater treatment
4. Conclusion
G. sulphuraria was shown to be capable of higher growth rate in the primary effluent than in the control medium. BOD removal rate by G. sulphuraria was shown to be greater than that of the activated sludge process; nutrient removals by this strain are comparable to those reported in the literature. Since mixotrophic metabolism does not require energy for oxygenation, it can conserve the energy currently consumed for aerobic BOD removal. By converting most
of the carbon in the wastewater to biomass, it enables higher energy recovery than by current practice. Mixotrophic approach has the potential for energy-positive wastewater treatment.
Acknowledgements
This study was supported in part by the NSF Engineering Research Center, ReNUWIT award # EEC 1028968; NSF NM
EPSCOR award # IIA-1301346; DOE Regional Algal Fuels Testbed Partnership Award #DE-EE0006269; and the Ed & Harold Foreman Endowed Chair