The selection of adequate plant species is a prerequisite for cleaning-up trace metal contaminated-soils by phytoaccumulation which is a cost-effective and environmentally-friendly technology. The potential of Panicum maximum, Eleusine indica and Cynodon dactylon to uptake trace metals from the soil of the Akouedo landfill was investigated. The concentrations of trace metals in soil were also considered. Moreover, the accumulation of Zn, Ni, Cu, Pb and Cd was assessed based on bioconcentration factor, translocation factor. The results showed high concentration values in the soil of the abandoned and the operation site of the landfill compare to the control site. The highest concentrations of trace metals in the plant shoot were observed with P. maximum for Ni. In root biomass, Zn, Cu and Cd showed high concentrations with P. maximum, E. indica and C. dactylon. Furthermore, the highest values of bioconcentration factor (BCF) and the translocation factor (TF) for Ni, were respectively 111.98 ± 82.45 and 4.26 ± 1.75 and were recorded with P. maximum. P. maximum, suggesting that it can be considered as a Ni hyperaccumulator.

This study aims to investigate the capacity of Chrysopogon nigritanus to accumulate As from contaminated soils. The experiment was conducted in a greenhouse. C. nigritanus was subjected to uncontaminated soil and As contaminated soil (50 mg/kg, 100 mg/kg and 150 mg/kg of As), for 180 days. Plant growth and biomass produced, concentration of As in soil and plant, bioaccumulation and transfer factors, as the location of As in tissues and cells of the plant have been determined. Plant growth decreased significantly with increasing of soil As concentration. C. nigritanus accumulated more As in roots biomass. The highest bioaccumulation factor values were found in contaminated soil at 50 mg As/kg (As 50), then contaminated soil at 100 mg As/kg (As 100) and contaminated soil at 150 mg As/kg (As 150). As was essentially fixed to the intracellular compartment of the roots, stems and leaves. In roots tissues, As was mainly retained in the rhizodermis and the pericycle. While in stems tissues, As was preferentially accumulated in the conductive bundles. In the leaves, the final destination of As was epidermis tissues.