A study on the adsorption of zinc, copper, cadmium and lead elements in leaves of some woody species

Using plant species to adsorb pollutants is one of the common methods of environmental cleanup. Zinc Industrial Park within five kilometers south of Zanjan city is a source of environmental contamination. In this paper, some woody species absorbing heavy metals including copper, zinc, cadmium, and lead, and the extent of the contamination were investigated. In the control area, within Zinc Industrial Park boundaries, and the radii of 0-1, 1-3, and 3-5 kilometers from Zinc Industrial Park leaf samples of six woody species including black locust, ash, white poplar, black poplar, rose, and willow were collected. Heavy metals concentrations were measured and statistical analysis was carried out under the assumption of split-plot design based on completely randomized block design. The results showed that high contamination levels of zinc, cadmium and lead are detectable in a radius of five kilometers from Zinc Industrial Park. Copper contamination level was below the critical level. But the amount of lead pollution within the Zinc Industrial Park is threatening. The best species for phytoremediation of Cadmium and Zinc is white poplar.