The use of willow microcuttings for phytoremediation in a copper, zinc and lead contaminated field trial in Shanghai, China

Abstract

A phytoremediation approach using willow microcuttings was tested on a large experimental site spiked with Cu, Pb and Zn. The objective was to verify if this approach allows plant establishment and effective extraction of contaminants. The experimental design consisted of four blocks divided into three plots, in which treatments (salts of the three metals) were randomly applied. Each plot was also subdivided to verify the effect of adding diverse compost treatments: no compost, vegetable garden waste compost (Compost 1), food waste compost (Compost 2) and a mix of Composts 1 and 2. Willow microcuttings (Salix matsudana × alba) were scattered on the plots at a density of 60 m⁻². Nine months after the implementation, the number of stems developed, yield and concentration of metals in the aerial parts of the willows were measured. The presence of a contaminant did not affect the number of stems developed. However, the presence of Compost 1 had a significant effect on the number of stems produced as well as on the biomass. Among the three metals, Zn was the element found in highest concentration in willow tissues. An estimated minimum 300 g of Zn per hectare per year could be removed using this method.

Keywords:

• Microcuttings
• phytoextraction
• Salix
• trace elements

Acknowledgments

We are grateful to Stéphane Daigle for his help with statistical analysis, Shumeng Kou and Zhang Guowei for technical support and Karen Grislis for revising the English style of the manuscript. We would also like to thank the Chenshan Botanical Garden for making the study site available to us for the purposes of this study and for regularly providing support for maintaining the plantation.

Additional information

Funding

This work was financially supported by grant from the Shanghai Administration Bureau of Landscape and Appearance [Grant No. G182420], the Quebec Research Fund – Nature and Technology (FRQNT), the Shanghai Committee of Science and Technology, China [Grant No. 18DZ1204700, 18DZ1204701].