Assessment of Potential Indigenous Plant Species for the Phytoremediation of Arsenic-Contaminated Areas of Bangladesh

Abstract

Soil and water contaminated with arsenic (As) pose a major environmental and human health problem in Bangladesh. Phytoremediation, a plant-based technology, may provide an economically viable solution for remediating the As-polluted sites. The use of indigenous plants with a high tolerance and accumulation capacity for As may 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 As-contaminated (groundwater) districts in Bangladesh. The main criteria used for selecting plants for phytoremediation were high bioconcentration factors (BCFs) and translocation factors (TFs) of As. From the results of a screening of 49 plant species belonging to 29 families, only one species of fern (Dryopteris filix-mas), three herbs (Blumea lacera, Mikania cordata, and Ageratum conyzoides), and two shrubs (Clerodendrum trichotomum and Ricinus communis) were found to be suitable for phytoremediation. Arsenic bioconcentration and translocation factors >1 suggest that these plants are As-tolerant accumulators with potential use in phytoextraction. Three floating plants (Eichhornia crassipes, Spirodela polyrhiza, and Azolla pinnata) and a common wetland weed (Monochoria vaginalis) also showed high BCF and TF values; therefore, these plants may be promising candidates for cleaningup As-contaminated surface water and wetland areas. The BCF of Oryza sativa, obtained from As-contaminated districts was >1, which highlights possible food-chain transfer issues for As-contaminated areas in Bangladesh.

KEY WORDS:

• Bioconcentration factor (BCF)
• hyperaccumulator
• phytoextraction
• translocation factor (TF)

ACKNOWLEDGEMENTS

The authors gratefully acknowledge the assistance of the crop scientists at the Bangladesh Agricultural Research Institute (BARI) for the identification of plant species. The authors would also like to express their gratitude to the field workers and administrators of ADAMS (an NGO working in the As-prone area of Bangladesh), who contributed their valuable time during our field trip in Bangladesh. The helpful comments and suggestions of three anonymous reviewers are also greatly appreciated.

Notes

^†Ratio of As concentration in whole plant biomass to that in soil.

^‡Ratio of As concentration in top biomass to that in root biomass.

*Mean ± standard deviation.

^†Ratio of As concentration in whole plant biomass to that in soil.

^‡Ratio of As concentration in top biomass to that in root biomass.

*Mean ± standard deviation.