| Municipal wastewater has long been recognized as a major nutrient source to surrounding aquatic ecosystems. The use of microalgae to remediate wastewater nutrients has been proposed by scientists for decades, but has not achieved large-scale success. Recently, microalgae have been proposed as a feedstock for biofuel production, but this has also not achieved large-scale success due to biological, engineering and economic constraints. Coupling microalgal wastewater remediation with microalgal biofuels production would potentially make microalgal biomass technologies much more cost effective. In this study, I attempted to: (1) test, and optimize, microalgal growth dynamics in municipal wastewater effluent; 2) quantify nutrient removal capabilities of microalgae in wastewater. The results of 12-day batch culture laboratory experiments and 7-day field experiments showed that both species were able to achieve net growth in wastewater, and that increasing CO2 concentrations enhanced the overall growth of both microalgal species. Nutrient removal by both species, specifically of nitrate, was substantial and tended to be more rapid in CO2 enriched treatments. Relatively high lipid content was noted for both species as well. These results indicate that algae represent a realistic possibility as an alternative fuels source. With further research and development, the process may be streamlined and the cost reduced and may be very competitive with traditional fossil fuels. |
