The horizontal and vertical migration of heavy metals may occur in the coal gangue-filled reclamation area, which would affect the food security. The distribution and migration of heavy metals, collected around Liuxin mining area filled by coal gangue for land reclamation in Xuzhou, were investigated. The source of coal gangue mudding at 42 cm from the surface soil was analyzed. In the vertical migration, the content of Pb in soil decreased firstly and then increased. Affected by plant roots, the upward range of Pb migration in coal gangue was about 20 cm; due to the effect of ambient environment, the downward range was also about 20 cm. In the horizontal migration, accumulation of Pb was likely to occur in the surface soil far distant from the reclamation area and in the deep soil near the reclamation area. After filling coal gangue for land reclamation, the content of Pb in wheat showed a trend of decreasing with the increased distance from the reclamation area. In the reclamation area, Pb was likely to accumulate in the roots of wheat; out of the reclamation area, the part of wheat where Pb accumulates depended on the distance of crop planting to the reclamation area.% 煤矸石充填覆土过程中重金属可能会向上或水平方向迁移，进而影响食品安全。以徐州柳新矿区煤矸石充填复垦地为研究对象，研究Pb在土壤环境中的纵向和水平分布及迁移情况。以距离地表42 cm处泥化后煤矸石为源强分析，纵向迁移结果表明，土壤中Pb含量呈现先减少后增大的趋势，原因在于煤矸石中Pb在植物根系影响下向上迁移范围在20 cm左右，而表层土壤受外界环境影响造成Pb含量较多，向下迁移范围亦在20 cm左右；横向迁移结果表明， Pb更易于在远距离复垦区表层和近距离复垦区深层累积；煤矸石充填复垦后，随着与复垦区距离增大，小麦植株Pb含量呈现减少趋势，在复垦区内Pb易于在小麦植株的根系中累积，在复垦区外Pb在小麦植株中的累积部位则由与复垦区的距离决定
展开▼
