Phytoremediation of zinc contaminated soils using silver birch (Betula pendula Roth)

•Usefulness of Betula pendula in phytoremediation of soils contaminated with Zn.•Identification of B. pendula as a hyperaccumulator of Zn.•B. pendula caused depletion of Zn in the soil and reduction of its content in plants.

The purpose of this study was to evaluate the usefulness of Betula pendula for the phytoremediation of soils contaminated with Zn. The trees grew on highly contaminated mounds of metallurgical waste under control conditions. The study demonstrated the ability of this species to accumulate high amounts of Zn in its leaves, in both the controlled and in the contaminated environments. The content of Zn in the soil and in the leaves of Solidago virgaurea near the trees was significantly less than at 7 m away. In the heavily polluted environment, this resulted in “cleansing” of the soil, and in the environment of background contamination, the effect was soil depletion and the reduction of Zn in plants. B. pendula satisfies the conditions required for plants used in phytoremediation and can be practically applied to clean soils contaminated with Zn. The authors propose the inclusion of B. pendula in the group of hyperaccumulators of Zn.