Award

Carbon dioxide (CO2) levels in the atmosphere are the highest in over 650,000 years (Science, 11-25-05), reinforcing the need to slow or even reverse this upward trend. The combination of municipal wastewater treatment with microalgal biofixation of CO2 would represent a novel, cost-effective means to decrease greenhouse gas emissions and fix CO2. Microalgae can fix CO2 at high rates, producing a biomass that can be converted to biofuels to replace fossil fuels. Research is needed to prove that the addition of CO2 to ammonia-rich wastewater-treatment ponds would increase the efficiency of CO2 fixation, as well as reduce pollutant nitrogen and phosphorus to the low levels required by water quality regulations. This project will develop a microalgae-based carbon sequestration technology using power plant flue gases for CO2 and municipal wastewaters as nutrient sources. The algal biomass harvested from mass culture ponds will be converted to methane fuel to be used as substitute for fossil fuels, with the residues used as fertilizers. Phase I will demonstrate, at the laboratory scale, that the CO2-supplemented primary effluent (settled sewage) will provide a much higher algal biomass yield and more nutrient removal, compared to controls without CO2 addition. In addition, a suitable site will be arranged for a Phase II pilot project; and a feasibility analysis ¿ which will include engineering, economics, balances of mass and energy, and greenhouse gas abatement potential ¿ will be developed. Commercial Applications And Other Benefits as described by the Applicant: The technology should be applicable to the removal of nutrients from municipal wastewaters to prevent pollution of receiving waters. The new process should result in the production of biofuels and fertilizers and the capture and recycling of power-plant flue-gas CO2, providing sufficient revenues to allow the abatement of greenhouse gas emissions to be accomplished.