Integrated Dairy Waste Management

Project Summary: Dairy products are California's top agricultural commodity. Operational costs are increasing substantially at many dairies due to new environmental regulations. Several faculty members are involved with development of improved methods to manage dairy waste to lower cost and recover nutrients and energy. An innovative method being developed is the integration of algae production with treatment of dairy wastewater. First, anaerobic treatment of the wastewater produces methane for electricity generation and effluents rich in nutrients for algae production. As algae grow, waste nutrients are assimilated and oxygen is created for waste treatment, both with a much lower electricity input than conventional treatment technologies. In addition to performing treatment, algae may be used as biodiesel feedstock and/or animal feed. Currently, the algal biomass produced during wastewater treatment is being evaluated for methane and oil biofuel potential. A techno-economic model has been developed to assess future scale-up of the technology. A multi-disciplinary group of faculty members and students from Civil and Environmental Engineering, Biology, and Chemistry Departments have been involved in the various components of the study.

Principal Investigator: Yarrow Nelson, Tryg Lundquist, and Ian Woertz

Funding Agency: USDA

Woertz, I., Feffer, A., Lundquist, T., and Nelson, Y., (2009), "Algae Grown on Dairy and Municipal Wastewater for Simultaneous Nutrient Removal and Lipid Production for Biofuel Feedstock." Journal of Environmental Engineering, ASCE, Vol. 135, No. 11, pp. 1115-1122.

Woertz, I., Lundquist, T., Kean, A., and Nelson, Y. M. (2007), "Production of Biodiesel from Algae Applied to Agricultural Wastewater Treatment" Presented at the EPA Sustainability Expo, Washington, D.C., April 24, 2007.