Phytoremediation and Accumulation of Cadmium from Contaminated Saline Soils by Vetiver Grass

Abstract

A soil-culture study was conducted to investigate the phytoextraction of cadmium (Cd) (20, 60, and 100 mg/kg) in two species of upland and lowland vetiver grass (Vetiveria nemoralis and V. zizanioides) with salinity levels of 1,000 mg/kg NaCl salt for 2 months. The two species of grass were highly tolerant to Cd and salt with little adverse effect on growth. Cd and salt treatments imposed significant negative effects on root length, shoot height and total dry biomass. Cd accumulation in the roots and shoots all increased significantly with increasing Cd concentration. The combined treatments of Cd and salt showed the highest root Cd accumulation in V. nemoralis (226―862 mg/kg) at Cd concentrations ranging from 20 to 100 mg/kg. Salt did not affect the accumulation of Cd but decreased the root-to-shoot Cd translocation. This was confirmed by the bioconcentration factor in root ＞ 1 and the translocation factor ＜ 1, which indicated the plant's suitability for phytostabilization of Cd under saline conditions. The experiment pointed out that V. nemoralis was a better accumulator of Cd than V. zizanioides.