Mon
24 Oct 2011Suitability of an organic residual cover on tailings for bioenergy crop production: A preliminary assessment
Jennifer Hargreaves1,2, Alan Lock1,2, Peter Beckett2 , Graeme A. Spiers1,2, Bryan Tisch3 , Lisa Lanteigne4 , Tamara Posadowski1,2, and Michael Soenens5
1MIRARCO, 935 Ramsey Lake Road, Sudbury, Ontario, Canada P3E 2C6; 2Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario, Canada P3E 2C6; 3Natural Resources Canada, 555 Booth Street, Ottawa, Ontario, Canada K1A 0G1; 4Vale, 337 Power Street, Copper Cliff, Ontario, Canada P0M 1N0; and 5Green Zone Farms, Azilda, Ontario, Canada P0M 1L0. Received 5 December 2010, accepted 24 October 2011.
To test the potential for production of bioenergy crops, such as canola and corn, an organic cover was constructed over acid-producing mine tailings containing nickel and copper, belonging to Vale in Sudbury, Ontario, Canada. The 1-m-deep cover was of organic residuals (biosolids) obtained from a regional paper mill.Corn and canola crops were successfully grown using agricultural techniques. Crop yields from each of 2yr from the tailings site were greater than those obtained at an agricultural site in the region. Root, shoot and grain analyses indicated low potential for bioaccumulation of potentially hazardous metals from the organic residual cover or the underlying tailings. Over the short term, there was no evidence of metal movement into the biosolids cover or uptake by the crops from the underlying tailing deposits. Importantly, canola seeds and corn kernels, the feedstocks for biodiesel and ethanol biofuels production, did not accumulate environmentally sensitive metals. This preliminary study demonstrates that the placement of an organic residuals cover on mine tailings to support growth of bioenergy crops is a potential novel reclamation strategy for the mining and smelting industry, or for industrial brownfields in general.
