Phytoremediation of arsenic contaminated soild by Eucalyptus camaldulensis, Terminalia arjuna and Salix tetrasperma

Abstract

Rising levels of arsenic in ground water posing threats to millions of people residing in Indus plains whereas the magnitude of the risk is alarming need to control arsenic from leaching down into ground water becomes essential. The study was designed to assess the potential of three native tree seedlings to reclaim the arsenic affected soils in Pakistan.  The study aimed at determining the impact of arsenic application on growth parameters of tree seedlings and accumulation of arsenic in plant parts. The laboratory experiment conducted at the Botanical Garden, University of the Punjab, Lahore revealed that E. camaldulensis, T. arjuna and S. tetrasperma have demonstrated varying adaptability to survive under the arsenic stress environment, establishing them as strong candidates to be exploited for arsenic remediation process.  Arsenic treated plants showed reduced growth in terms of stem height, stem diameter, number of branches, number of leaves, root length, total plant length and biomass production as compared to plants grown without arsenic treatment. Arsenic accumulated in all vegetative parts of the plants, however, maximum arsenic accumulation was recorded in roots of E. camaldulensis (37.25 µg kg^-1) followed by S. tetrasperma (35.76 µg kg^-1) and T. arjuna (24.13 µg kg^-1) when arsenic was applied @ 4.0 mg L^-1. The study has shown that these trees can be grown on arsenic contaminated fields to reclaim the soil from arsenic content resulting in its substantial reduction leaching in groundwater.