Abstract
In this paper, in order to address the common serious soil pollution by heavy metal in the surroundings of coal and copper mines in China, we select heavy metal accumulating plants suitable for remediation of copper and coal mine soil, measure the contents of heavy metal elements in the plants and analyze the enrichment and transfer of heavy metal in plants to study the potentials of different plants to remediate heavily polluted soils in coal and copper mines. The study on phytoremediation of heavy metal polluted soil surrounding coal mines shows that the contents of the same heavy metal are different in five different plants, and the aerial and underground parts of the same plant absorb different amounts of the metal. All these plants show strong accumulation of Ni, Cr, Pb and Cd. The transfer coefficients of most heavy metal elements to Jerusalem artichoke and Erigeron annuus are greater than 1, which make them hyperaccumulating plants. The results of the study on remediation plants for heavy metal polluted soil in coal mines show that, with the increase in the proportion of copper slag in the soil, the germination rate, root length and seedling growth height of clovers, alfalfa and amorpha fruticosa increase first and then decrease, i.e. “low-promoting and high-repressing”. The three kinds of plants with content of copper from high to low are amorpha fruticosa, clover and alfalfa, and those with an increase in copper absorption compared with a copper concentration of 0% are clover, amorpha fruticosa and alfalfa from large to small. Clover absorbs a larger amount of copper in the copper-contaminated soil and when the concentration of copper in the soil is high, it is the least inhibited in growth, so it is an ideal choice of remediation plant for the copper-contaminated soil around copper mines.
