|Broadhurst, C Leigh|
Submitted to: Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 11/5/2006
Publication Date: 6/26/2007
Citation: Chaney, R.L., Broadhurst, C., Davis, A.P., Tappero, R.V., Sparks, D.L., Wood, B.R., Crawford, M. 2007. Recycling Ni from Contaminated and Mineralized Soils. Meeting Proceedings. June 26-29, 2007. Golden, Colorado. Interpretive Summary: .
Technical Abstract: Rare plant species accumulate potentially valuable concentrations of some metals. Alyssum murale readily accumulates over 2% Ni in aboveground dry matter when grown on Ni-mineralized serpentine soils in Oregon, allowing production of “hay” biomass with at least 400 kg Ni ha-1 with low levels of fertilizer inputs. The project team selected several Alyssum Ni hyperaccumulator species for commercialization, developed farming methods to grow the crop, and bred improved cultivars for commercial use on either mineralized or Ni-contaminated soils (funding from Viridian LLC). Serpentine soils with 0.1-1.0% Ni are found in OR, CA, WA, NC and some other states and other nations. The plants tolerate this massive level of leaf Ni by selectively pumping the Ni in vacuoles of epidermal cells. We have reported research on the localization of Ni and Co storage in these plants, showing remarkable storage in the vacuoles in the base of trichome cells, while the trichomes have much Ca but little Ni. These soils are usually very low in plant available Ca, N, and P, and usually are covered with serpentine adapted species. However, addition of normal fertilizers allows production of high yields of biomass Ni. Ni metal is presently worth about $35 kg-1, offering considerable profit potential for everyone needed for practical phytomining (landowner, farmer, patent licensee, and smelter operator). The ash of Alyssum biomass can exceed 20% Ni, in a matrix of plant nutrients. Ni was recovered from the ash using an electric arc furnace with usual management. In addition to use as a high grade Ni ore, biomass can serve as an “organic” fertilizer for Ni fertilization of Ni deficient plant species. Pecan and some other crops grown on low Ni coastal plain soils in GA require Ni fertilizers for normal growth. Alyssum biomass was extracted with water and the Ni was at least as effective as NiSO4 in correcting Ni deficiency of pecan.