Study on soil pollution caused by heavy metals in coal mining areas and vegetation restoration in surrounding areas

In this study, taking a coal mining area as an example, three vegetation restoration modes were designed: Populus L. , Ligustrum lucidum Ait. , and Amygdalus persica L. , and soil and plant samples were collected to determine and evaluate the heavy metals. It was found that all the three modes were effective in eliminating heavy metal pollution in the soil, especially Populus L. and Ligustrum lucidum Ait. ; in the soil layer at a depth of 0–20 cm, the content of Cd was the lowest (2.68 mg/kg) in Populus L. , and the content of Cr and Pb was the lowest (58.64 mg/kg and 95.36 mg/kg) in Ligustrum lucidum Ait. , which was significantly lower than that in the bare land. The evaluation results demonstrated that the pollution under Populus L. and Ligustrum lucidum Ait. modes was moderate. In the aspect of the heavy metal content in plants, the content of Cd was the lowest, and the content of Cr and Pb was high. In the same plant, the content of heavy metals in the leaf was the lowest, followed by the stem and root. The experimental results show that the vegetation restoration mode can relieve the heavy metal pollution, which makes some contributions to solve the ecological restoration problem in coal mining areas.