The effects of rice husk ashes and inorganic fertilizers application rates on the phytoremediation of gold mine tailings by vetiver grass

This study investigated the effect of rice husk ash (RHA) and inorganic fertilizer on the phytoremediation of heavy metals in mine tailings by vetiver grass (Vetiveria zizanioides L. Nash). The mine tailings were amended with either RHA or iron-coated RHA (Fe-RHA) at 0 or 10% (w/w) application rates and vetiver grass was planted on the tailings. The vetiver grass was fertilized with three rates (0, 50 and 100 kg ha−1) of NPK fertilisers during the 75 days growth period in a glasshouse and the experimental units were arranged in a randomized complete block design. At harvest, the shoot and root of the plants were separated and their uptake of As, Cd, Cu, Cr, Pb, Mn and Zn were determined. Application of RHA showed an increase (p