湖南省典型地区水田土壤锑和砷元素纵向迁移行为分析

为探讨锑(Sb)和砷(As)在土壤中的纵向迁移行为及其差异，采集湖南省典型地区水田土壤20个剖面共100个样品，对水田土壤中Sb和As的含量、垂直分布特征及其纵向迁移行为差异进行研究，为湖南省水田土壤环境影响评价和污染防控以及进一步探寻Sb和As环境行为和来源提供科学依据。结果表明：水田土壤Sb和As含量分别为1.61±1.79 mg/kg和13.48±6.57 mg/kg; Sb在表层土壤富集，Sb随深度的增加含量逐渐下降，As在土壤剖面中累积明显，随深度的增加含量逐渐上升。两者相比，As元素在水田土壤周期性氧化还原过程中淋溶释放更强烈，其纵向迁移能力也更强。Sb和As在土壤中表现不同氧化还原性质是影响其纵向迁移行为的主要因素，土壤理化性质及成土母质也在一定程度上影响了Sb、As的纵向迁移。

Vertical Migration Behavior of Antimony and Arsenic in Paddy Soil in Typical Areas of Hunan Province

In order to investigate the vertical migration behavior of antimony(Sb) and arsenic(As) in paddy soil and their differences, a total of 100 samples from 20 soil profiles of paddy soil in typical areas of Hunan province were collected. The contents, vertical distribution characteristics and their differences in vertical migration of Sb and As in paddy soil were studied. These results provided a scientific basis for environmental impact assessment and pollution prevention in Hunan Province and also for further exploration of environmental behavior and source of Sb and As. The results showed that the contents of Sb and As in paddy soil were 1.61±1.79 mg/kg and 13.48±6.57 mg/kg, respectively. Sb was enriched in the surface soil, and decreased with the increase of depth. As was accumulated in the soil profile, and the content of As increased gradually with the increase of depth. For the two heavy metals, the leaching release of As was more intense in the periodic redox process of paddy soil, and its vertical migration ability was also stronger. The difference redox properties of As and Sb in soil were the main factors affecting their vertical migration behavior. The physical and chemical properties of soil and the parent material of soil also affected the vertical migration of Sb and As to some extent.