广东云浮含Tl硫酸冶炼堆渣场土壤Tl污染的元素-Pb同位素示踪研究

Element and lead isotope tracing to the thallium pollution in soil profiles from a thallium-containing slag pile site in a sulphuric acid plant in Yunfu city, Guangdong Province

利用元素总量和Pb同位素示踪技术对广东云浮硫酸厂含Tl黄铁矿冶炼堆渣场周围土壤中Tl的污染程度和迁移行为进行了研究。研究发现堆渣场周围土壤中Tl污染物主要集中于表层土壤约16.5cm深度内,并且表现出沿垂直方向向下迅速下降的特点。堆渣场周围土壤中Tl与Pb呈显著线性相关,表明自然条件下Tl与Pb在土壤中的迁移相似性,并且都以横向迁移为主。堆渣场固结层周围土壤至少44cm范围已经受到废渣中Tl释放的影响,Tl污染物平均下渗速率达到2.75cm/a。酸性雨水的淋滤作用及废渣自身不断酸化的特性是废渣中Tl迁移释放入土壤的主要因素,土壤铁氧化物胶体及有机质是土壤对Tl产生吸附的主要载体。

The thallium contamination status and migration behaviour in soil around the deposed acid waste slag from a sulphuric acid plant in Guangdong province were intensively investigated isotope tracing. The research finds that thallium pollutants were mainly concentrated by applying element and lead in surface layers of soils （0 - 16.5 cm） and decrease rapidly downward. Significant linear correlation between the distribution of thallium and lead was found at profiles A and B, which indicates thallium and lead released from slags have similar migration behavior in soils. Both elements migrate mainly transversely in the soil around the waste slags. The soils within 44 cm away from waste slags were contaminated by thallium, corresponding to a migration rate of 2. 75 cm/a in average. The main factors that control thallium releasing ability from slags to soils were leaching by acid rain and the continuous acidification characteristics of waste slag itself. Iron oxide colloid and organic matter may be responsible for the thallium retention in soil.