Strategy on rapid selection of woody species for phytoremediation in soils contaminated with copper, lead and zinc in Shanghai

Abstract

The use of woody species for the remediation of heavy metal-contaminated soils is an environmentally friendly and economically viable strategy. This study investigates the phytoextraction abilities of 15 woody species for copper, lead and zinc in contaminated soil. The results indicated that all species showed phytoextraction ability, with metal concentrations varying from 5.59 to 27.45 mg·kg−1 for Cu, 2.79 to 16.75 mg·kg−1 for Pb and 22.13 to 185.72 mg·kg−1 for Zn in the stem tissues depending on the species. Pterocarya stenoptera, Paulownia fortunei and Salix matsudana were identified as the top performers in terms of overall phytoextraction capacity. Notably, their capacity to transport zinc exceeded that of copper and lead. The enrichment of copper, lead and zinc in the soil showed a synergistic effect in the presence of heavy metal. The distribution of heavy metals within plant tissues was affected by water content and the inherent toxicity of metals. The study highlights that the accumulation of tree biomass and water content in the stem play a significant role in determining the amount of heavy metals phytoextracted. This insight offers a quick method for the rapid selection of woody species for phytoremediation in urban soils contaminated with heavy metals.