Evaluating the capacity of heavy metal pollution enrichment in green vegetation in the industrial zone, Northwest China

It focused on heavy metal pollution of green vegetation in Tuokexun County, Xinjiang Northwest China's suburban industrial area, using inductively coupled plasma emission spectrometer to analyze the samples for Mn, Ni, Zn, Cd, Hg, Pb, As, Cu, and Cr contents. The soil's heavy metal content in the study area indicated a minor level of pollution overall (P = 1.77), with the most severe contamination being Hg, which is more likely to be caused by human activities. Heavy metal elements in trees have the most stable composition in comparison to grass and shrubs, with varying concentrations across different vegetation. The concentrations of Mn, Cd and Hg were highest in the Haloxylon ammodendron, Ni in Morus alba, Pb, As and Cu in Nitraria tangutorums, and Cr in Phragmites australis. Heavy metal restoration is most effectively performed by shrubs, and there are disparities in heavy metal enrichment among various vegetation. No significant difference was found in heavy metal enrichment between the aboveground and underground parts of vegetation. Based on the average of the membership function, Tamarix exhibits the strongest ability to enrich heavy metals, while Nitraria tangutorum comes in second, and Cynanchum chinense R.Br. is the least effective among all plant species. Morus alba is recommended as the primary planting species in the area. Nitraria tangutorum and Haloxylon ammodendron have good potential for Cd and As restoration and can be used as supporting vegetation.