江西某铜矿弃渣场下游农田土壤重金属分布特征研究

Distribution Characteristics of Heavy Metals in Downstream Farmland Soil of Copper Mine Spoil Yard in Jiangxi Province

研究了江西某铜矿3处弃渣场拦渣坝下游污染农田的土壤重金属Cu、Cd、Pb、As、Sb、pH、有机质的垂直空间分布特征。结果表明:污染土壤pH随土壤深度增加而增大,重金属全量、有机质质量分数呈现5~10 cm>0~5 cm>10~20 cm>20~30 cm的分布规律,且5~10、0~5 cm土层的重金属全量明显高于10~20 cm和20~30 cm的,重金属在垂直空间分布上呈现一定的表聚效应。变异系数分析表明,重金属全量在土壤垂直空间的变异程度既受土层间因素影响,也受地块间因素的影响。相关性分析则表明,土壤重金属之间具有一定的正相关性,说明其来源相似;Cu、Pb、As、Sb与有机质质量分数之间呈正相关;Pb、As、Sb与pH之间,Cu、Pb、Sb、As与土层深度之间均呈负相关。

The vertical spatial distribution characteristics of Cu、Cd、Pb、As、Sb、pH and organic matter in the polluted farmland downstream of three spoil yard in a copper mine in Jiangxi Province were studied. The results showed that the pH of contaminated soil increased with the increase of soil depth, while the contents of heavy metals and organic matter showed a distribution pattern of 5~10 cm>0~5 cm>10~20 cm>20~30 cm. The contents of heavy metals in soils 5~10 cm and 0~5 cm deep were significantly higher than those in 10~20 cm and 20~30 cm, indicating that heavy metals had a certain surface accumulation effect in vertical spatial distribution. The coefficient of variation analysis showed that the variation of heavy metal content in vertical space of soil was affected by both interlayer factors and interblock factors. The correlation analysis showed that there was an extremely significant positive correlation among heavy metals in soil, indicating similar sources of heavy metals. There was a positive correlation among Cu, Pb, As, Sb and organic matter,and a negative correlation among Pb, As, Sb and pH, and among Cu, Pb, Sb, As and soil depth.