Submitted to: Government Publication/Report
Publication Type: Other
Publication Acceptance Date: September 15, 2008
Publication Date: January 2, 2009
Citation: Banuelos, G. Agriculture Research Initiative Research Report. ARI No. 03-2-002. Interpretive Summary: The use of green plants for environmental management of selenium has been called “phytoremediation”. Scientists at the WMRU have determined that members of the Brassica family,e.g., canola, mustard, can be used for the phytomanagement of selenium. They hypothesized that by using these types of plants for managing the soluble selenium from the soil and drainage waters, high commodity byproducts can be produced, such as selenium-enriched animal feed, and using extracted oil from the seeds for the production of biofuel. On-site oil press equipment allows for the researchers to extract oil from the seed. After the oil has been tranesterfied, biodiesel blends of BD 20 can be produced (20% canola or mustard oil and 80% diesel), and diesel-powered irrigation booster pumps can be operated. Moreover, the residual seed meal is now available as a nutritious supplement of selenium for the dairy industry. This report discusses the derivation and production of economical byproducts that were developed from Brassica crops grown for the management of natural occurring selenium in soils and waters in the Westside of Central California.
Technical Abstract: Many of the Brassica plant taxi that are candidates for phytoremediation of selenium also produce products that be used for refining into biodiesel, as well as selenium enriched animal feeds. These include canola (Brassica napus) that is planted in the Westside soils of central California (Oxalis silty clay formed with naturally high levels of water soluble Se ranging from 0.15 to 1.0 mg/L. After growing canola crops for the management of soluble Se, seed yields can be has high as 1.3 tons/acre. Preliminary oil yields extracted from seed on site range from 130-160 gallons of 100% canola oil. Creating a B20 biodiesel (20% canola oil blended with 80% diesel) successfully powered irrigation booster pumps after transesterification of the biofuel. On a preliminary basis, we have also measured reductions of Cox, CO2, and THC emiited from B20 powered diesel engines. Reductions in NOX were, however, questionable. The byproduct from oil extraction was the residual seed meal with Se concentrations circa 2 mg/kg DM. The seed meal is available for use in dairy cow feed rations as a source of organic Se, and is presently being studied. Coupling phytoremediation of Se with biofuel production and animal Se feed production may provide California growers with a unique opportunity to develop energy crop systems for the management of Se in a sustainable manner.