Identification of potential indigenous plant species for the phytoremediation of arsenic contaminated sites of Bangladesh

摘要

Soils and waters contaminated with arsenic pose a major environmental and human health problem in Bangladesh. Phytoremediation, a plant based technology, may provide an economically viable solution for remediating the arsenic polluted sites. The use of indigenous plants with high tolerance and accumulation capacity of arsenic might be a very convenient approach for phytoremediation. To assess the potential of native plant species for phytoremediation, plant and soil samples were collected from four arsenic contaminated (underground water) districts of Bangladesh. The main criteria used for selecting plants for phytoremediation were high bioconcentration factor (BCF) and high translocation factor (TF) of arsenic. Of 30 plant species, only one species of fern (Dryopteria filix- mass), two herb (Blumea lacera and Ageratum conyzoides L.) and a shrub (Clerodendrum trichotomum), seemed suitable for phytoremediation, because the arsenic bioconcentration and translocation factors for these plants exceeded 1, which classifies these plants as an arsenic-tolerant plant with potential use in phytoextraction. The BCF and As accumulation efficiency of three floating plants (Eichhornia crassipes, Spirodela polyrhiza and Azolla pinnata) and a wetland plant (Monochoria vaginalis) were very high and these plants might be used for clean up the arsenic contaminated surface water and wetland area.