摘要
对中国西部4条冰川冰尘的粒度、总有机碳含量和10种重金属元素（Sc、V、Cr、Ni、Cu、Co、As、Pb、Cd和Zn）进行了分析，探讨了冰尘中重金属元素的分布特征和富集情况以及重金属元素与粒径、黏土含量和总有机碳含量之间的相关关系。结果表明，冰尘的粒径范围介于0．69～995．6μm之间，平均粒径大于20μm，总的重金属含量在七一冰川最高，其值为（507．61±22．53）mg／kg，木扎尔特冰川最低，其值为（40．06±12．42）mg／kg。冰尘中各重金属元素含量与粒径呈反相关关系，说明粒径越小，重金属元素含量越高；各重金属元素含量与总有机碳和黏土含量呈正相关关系，但相关性不显著，说明冰尘中含量较低的黏土和总有机碳对重金属元素的吸附能力较弱。富集因子表明，除木扎尔特冰川中Cd的富集系数大于10之外，其他元素的富集系数都在1附近，说明冰尘中的重金属元素主要来自岩石风化物和土壤粉尘。
In this study, the grain size, total organic carbon content and ten heavy metals （Sc, V, Cr, Ni, Cu, Co, As, Pb, Cd and Zn） contents of cryoconite in four typical glaciers in western China were measured. Distribution and enrichment pattern of heavy metals in the cryoeonite as well as correlation among heavy metals and cryoconite grain size, clay content and total organic carbon were analyzed. We found that the cryoconite grain size ranges between 0.69-995.6 μm with an average of 〉20 μm. The Qiyi glacier shows the highest total heavy metal content （507.61±22.53） mg/kg and the Muzart glacier shows the lowest total heavy metal of content （40.06±12.42） mg/kg. The heavy metal content in the cryoconite was found to be negatively correlated with the grain size, indicating that the heavy metal content is higher at smaller cryoconite grain size. The total organic carbon is positively but not significantly related with clay content, indicating that the limited amount of clay in the cryoconite shows weak adsorption towards organic carbon and heavy metals. The heavy metal enrichment factors for cryoconite in glaciers were calculated by using Sc as the reference element and by considering the Tibetan plateau topsoil as the reference level. Except for Cd in the Muzart glacier cryoconite, which shows an enrichment factor of-10, the enrichment factors for all other heavy metals in cryoconite from these glaciers were found to be generally around 1 and basically below 3, indicating that the heavy metals in cryoconite mainly originate from rock weathering residue and soil dust.
出处
《地球化学》
CAS
CSCD
北大核心
2015年第3期238-244,共7页
Geochimica
基金
中国科学院重点部署项目(KJZD-EW-G03-01)
国家自然科学基金(41201063
41471057
41171056)
关键词
冰川
冰尘
重金属
青藏高原
glaciers
cryoconite
heavy metal
Tibetan Plateau
作者简介
李全莲（1976-），女，博士、副研究员，主要从事雪冰化学研究。通讯作者（Corresponding author）： LI Quan-lian, E-mail： liql@lzb.ac.cn; Tel： ＋86-931-4967344
