罗布泊“大耳朵”地区具有典型的干盐湖特征, 研究该地区重金属形态分布特征, 对丰富干盐湖重金属地球环境化学资料具有重要意义。 首次以罗布泊“大耳朵”地区L07-11剖面沉积物中重金属Cd, Pb, Ni, Cu为研究对象, 利用Tessier连续提取法对沉积物中重金属Cd, Pb, Ni, Cu的五种赋存形态进行提取, 并用火焰(AAS-990)原子吸收分光光度法和石墨炉(GF-990)原子吸收分光光度法对其进行检测, 并做了相关性分析。 结果表明: L07-11剖面沉积物中Cd浓度的变化范围在1.10～2.54 mg·kg-1;Pb浓度的变化范围在9.18～20.02 mg·kg-1;Ni浓度的变化范围在9.88～17.15 mg·kg-1;Cu浓度的变化范围在4.43～21.11 mg·kg-1;有机质的变化范围在8.71～54.72 g·kg-1。 这四种重金属的生物有效态占各重金属总含量的比例大小顺序为: Cd＞Pb＞Cu＞Ni, 其中Pb和Cd主要以可交换态(包括水溶态)形式存在;Ni主要以残渣态形式存在;Cu以铁锰氧化物结合态和残渣态存在的比例较大。 表层沉积物中四种重金属的有效态含量均超过了80%, 除重金属Cu外, 其余3种重金属可交换态含量均超过60%。 重金属Cd和Pb具有较高的二次释放潜力, 各重金属与沉积物中有机质之间存在一定的相关性。 结果揭示了罗布泊“大耳朵”地区L07-11剖面沉积物中重金属Cd, Pb, Ni, Cu各赋存形态的分布特征, 为了解该地区Cd, Pb, Ni, Cu的地球化学特征及分布状况提供了基础资料。

As playa is the typical characteristic in “Big Ear” Region of Lop Nor Lake, it is significant for enriching playa heavy metal earth environmental chemical data by analyzing species distribution of heavy metal among this district. In this thesis, heavy metal Cd, Pb, Ni, Cu in L07-11 Profile Sediments of “Big Ears” Region of Lop Nor Lake are considered as research objects. Tessier sequential extraction and Graphite furnace atomic absorption method(GF-990) are used to discuss and analyze five forms of Cd, Pb, Ni, Cu among sediments. The results show that the content of Cd, Pb, Ni and Cu is in the range from 1.10～2.54, 9.18～20.02, 9.88～17.15, 4.43～21.11 mg·kg-1, respectively. The value of organic matter range from 8.71～54.72 g·kg-1. The order of the bioavailable state in heavy metals is Cd＞Pb＞Cu＞Ni. Pb and Cd mainly exist in exchangeable form including water-soluble, and that Ni is in residual form, and that Cu is mostly in Fe-Mn oxide bound iron-manganese oxides or in residual form. Among surface sediments, effective content of heavy metal is more than 80%. Except Cu, the content of heavy metal Cd, Pb, Ni in exchangeable form is more than 60%. Heavy metal Cd and Pb has higher secondary release potential. The content of heavy metal and organic material has some correlation.