Phytoextraction potential of Manihot esculenta Crantz. (cassava) grown in mercury- and gold-containing biosolids and mine tailings

Abstract

The potential of Manihot esculenta Crantz (cassava) to phytoextract Hg and Au from Hg- and Au-containing biosolids and mine tailings was successfully demonstrated for the first time. Removal of Hg by a hyperaccumulating plant species offers new options to clean up Hg-contaminated sites and at the same time harvest trace amounts of Au. Pre-rooted cassava cuttings with 5–7 nodes were grown in different combinations of biosolids-amended mine tailings to evaluate the best combination that will support optimum plant growth. The 75% biosolids – 25% mine tailings combination produced the best growth in cassava. Plant cuttings were also grown in hydroponics solutions amended with Hg and/or Au to det..