Phytoextraction of arsenic forms in selected tree species growing in As-polluted mining sludge

Abstract

The aim of this study was to determine the phytoextraction of inorganic (As(III), As(V)) and organic arsenic (As_org) forms in six tree species: Acer platanoides, Acer pseudoplatanus, Betula pendula, Quercus robur, Tilia cordata and Ulmus laevis. Plants were grown in a pot experiment using As-polluted mining sludge for 90 days. Arsenic (As_total) was accumulated mainly in the roots of all six tree species, which were generally thinner, shorter and/or black after the experiment. The highest concentration of As(III) and As(V) was determined in the roots of A. pseudoplatanus and A. platanoides (174 and 420 mg kg⁻¹, respectively). High concentrations of As(III) were also recorded in the shoots of B. pendula (11.9 mg kg⁻¹) and As(V) in the aerial parts of U. laevis and A. pseudoplatanus (77.4 and 70.1 mg kg⁻¹). With some exceptions, the dominant form in the tree organs was As_org, present in mining sludge in low concentration. This form has a decisive influence on As phytoextraction by young tree seedlings even though its BCF value was the only one lower than 1. The obtained results highlight the important role of speciation studies in assessing the response of plants growing in heavily polluted mining sludge.

Keywords:

• Arsenite
• arsenate
• dendroremediation
• phytoremediation
• mining sludge

Acknowledgements

The authors would also like to thank Jędrzej Proch for help and analytical support and also like to thanks the staff of the Turek Forest Division.

Additional information

Funding

The National Science Center of Poland financially supports this study under grant code Opus 2014/15/B/NZ9/02172 for Piotr Goliński.