Uptake, Translocation and Hyperaccumulating Potentials of Bahama Grass (Cynodon dactylon) for some Heavy Metals in Soil

Abstract

Heavy metals are popular pollutants due to their persistence, toxicity, accumulative nature in living things, and lack of biodegradability.  This study evaluated the phytoremediation potentials of Bahama grass (Cynodon dactylon) for Cr, Zn, Ni, Cd and Pb. Pot experiments  were conducted using soil (2 kg) mixed with Cr, Zn, Ni, Cd and Pb salt solutions. The soils were treated with Cr, Zn, Ni, Cd and Pb salt  solutions at a concentration of 100 ppm, 200 ppm, 300 ppm. Seeds of the grass (Bahama) were planted in to pots. Untreated soils (2 kg)  containing seeds of the grasses pots were used to serve as controls. The experimental pots were irrigated with 500 mL of water in the  evening hours for twelve weeks. The entire experiments were replicated four times for statistical purpose. After twelve weeks, the grass  samples were collected, washed and separated into root and shoot. The soil, root and shoot samples were digested and analyzed for the  heavy metals using AAS (Agilent 200 series Model No.240Fs). The result revealed that the Bioconcentration (BCF), Enrichment (EF) and  Translocation (TF) Factors generally decrease with increase in the concentrations of the heavy metals using the C. Dactylon. The highest  levels of BCF, TF and EF were 1.42 (Cd), 7.34 (Cd) and 1.36 (Ni) C. Dactylon. This indicate that the C. Dactylon is having highest  phytoextraction potential in the Cadmium-contaminated soils and highest phytostabilization potential in the Nickel-contaminated soils.  Therefore, C. dactylon have potential for phytoremediation of the heavy metal-contaminated soils.