Final Report: Cost-Effective Algae Biomass Production for Oil integrated with Wastewater Treatment and Valued By-ProductEPA Contract Number: EPD11036
Title: Cost-Effective Algae Biomass Production for Oil integrated with Wastewater Treatment and Valued By-Product
Investigators: Dahiya, Anju
Small Business: General Systems Research LLC
EPA Contact: Richards, April
Project Period: March 1, 2011 through August 31, 2011
Project Amount: $80,000
RFA: Small Business Innovation Research (SBIR) - Phase I (2011) RFA Text | Recipients Lists
Research Category: SBIR - Biofuels , Small Business Innovation Research (SBIR)
The Phase I project focused on developing a low-cost algal biomass production for oil by integrating the system with wastewater treatment, such as dairy farm manure, brewery wastewaters, and producing valued by-products, such as feedstock for biogas. The importance lies in the fact that a critical hurdle in terms of large-scale biomass production and a big economic barrier in the production of algae oil, i.e., the cost-efficiency of producing algae biomass, can be lowered by integrating with wastewater treatment as recognized by Department of Energy studies. The nutrient-rich wastewater from biodigesters or farm runoff is mostly organic material that algae can digest and utilize the nutrients (mainly nitrogen and phosphorus), which otherwise is a threat to natural water bodies. To grow oil-rich algae in such a medium could be a challenge, and no robust system exists. Unlike expensive algal closed systems (photobioreactors) under research, General Systems Research's (GSR) system is based on establishing a symbiotic relation between oil-rich algae and the bacterial system in open tank or pond systems. GSR tested two different process wastewater streams from two different facilities, a dairy farm and a brewery, using mixed and mono cultures of natural algal assemblage, GSR’s proprietary oil-rich algal strain(s), and a well-known strain of Chlorella vulgaris. The harvest was tested for oil lipid contents, and the water quality parameters, including nutrient concentrations of nitrogen and phosphorus, were analyzed. The algal biomass also was assessed for its possible use as feedstock for biogas.
- The results showed that the algal cultures reduced BOD in brewery wastewater by 97-99 percent and in dairy manure wastewater by 70-87.3 percent.
- The natural assemblage and monocultures of an isolated algal strain cultured in dairy manure wastewater in batch mode removed significantly higher amounts of ammonium nitrate nitrogen and total nitrogen compared to Chlorella cultures; however, in wastewater Chlorella cultures were more efficient in removal of ammonium nitrogen and nitrate nitrogen.
- The natural assemblage and isolated strain-based monoculture grown in brewery wastewater removed a higher amount of phosphorus compared to Chlorella cultures. Whereas, grown in manure wastewater, Chlorella cultures were more efficient in removing phosphorus.
- In the semi-continuous modes, the natural assemblage and isolated culture grown dairy manure wastewater were efficient in ammonium nitrate and phosphorus removal.
- The lipid accumulation, based on Ash Free Dry Weight (AFDW) of algae, was higher in the case of algae grown in brewery wastewater compared to the dairy manure wastewater. The isolated strains showed up to 1.27 to 1.60 times higher lipid content than Chlorella strain, which is known to accumulate lipid content up to 50 percent of AFDW. The (FAME) analysis for oil as triacyl glycerols (TAG) showed that the most abundant FAs obtained are from (C16:0) to (C20:3), the range required for biofuel production.