广西铅锑矿冶炼区土壤剖面及孔隙水中重金属污染分布规律

为探讨铅锑冶炼区重金属在土壤中分布及迁移特征,在广西河池铅锑矿冶炼区周围根据不同土壤利用类型分别选取菜地土壤、荒地土壤、林地土壤这3个典型剖面,对区域内土壤剖面及孔隙水中重金属的迁移分布特征进行了研究.结果表明,3个剖面中重金属元素Sb、Pb、As、Cu明显在表层富集,最高值都出现在0～2 cm的表层土壤中;Sb、Pb和As在剖面60 cm以下有增加的趋势.土壤剖面中重金属元素淋溶难易的总体顺序为:Sb>As>Cu>Al,Pb.土壤的耕作对重金属在剖面中的下渗迁移具有一定的影响.表层土壤孔隙水中高含量的重金属可能对作物造成毒害影响,并通过食物链危害居民的健康.Sb、As相对于Pb容易从土壤进入孔隙水,在剖面中迁移.

Characteristics of Heavy Metals in Soil Profile and Pore Water Around Hechi Antimony-Lead Smelter,Guangxi,China

In the area around an antimony-lead smelter, soil and soil water samples were collected from different soil profiles in vegetable field, uncultivated field and wood field. The distribution and migration of heavy metals in soil profile were investigated. In soil, Sb, Pb, Cu and Cd are found to accumulate in the topsoil layer, and decrease rapidly with the depth. However, Sb, Pb, and As appear to accumulate below 60 cm. Sb and As show a much stronger affinity to the pore water than Pb. In consequence, different soil utilization types lead to different effects of heavy metals migration in soil profile. Furthermore, Sb and As show a higher potential to migrate along the soil profile than that of Pb. In addition, the high content of heavy metals in the topsoil may be absorbed by crops post to desorption in soil water, and possibly form a threat to human health.