湘江竹埠港段河床沉积物元素地球化学特征

湘江是我国重金属污染最严重的河流之一。本次工作利用X射线荧光(XRF)和电感耦合等离子质谱(ICP-MS)分析技术,对湘江竹埠港沉积物进行主量和微量元素分析。结果表明沉积物主量元素含量变化相对稳定,富集MnO、P2O5、Fe2O3、Al2O3,亏损CaO、Na2O。微量元素含量变化较大,亏损Ba、Sc、Mn、Sr而富集其他微量元素。对主量元素和稀土元素进行了分析,表明沉积物物源主要是由上游花岗岩风化所提供。对沉积物进行因子分析和相关性分析,表明沉积物源主要以陆源碎屑为主,并有磷灰石和软锰矿等自生副矿物,Ni、Pb、Cu可能来自人为污染源。地累积指数表明Ba为清洁无污染,重金属V、Cr、Co、Ni、Th、U为轻度污染,重金属Cu、Pb、Zn为偏中度污染,Mn为中度污染,Sc为偏重度污染。其中重金属Cr、Ni、Cu、Pb、Zn、Mn、Sc污染应引起关注。

Geochemical Characteristics of Elements in the Sediments of Zhubugang Xiangjiang River

The Xiangjiang River is one of the most serious heavy metal pollution river in China.Concentration of major elements and tract elements in sediments from the Zhubugang Xiangjiang River in Hunan Province(China) were analyzed using the XRF and ICP-MS techniques. Results show that concentration of major elements in the sediments are relatively less variable,i.e.the chemical composition of the sediments is characterized by significant depletion of CaO、Na2O,and by relative enrichment of MnO、P2O5、Fe2O3、Al2O3、LOI. Concentration of trace ele-ments in the sediments are widely variable, i.e. the chemical composition of the sediments is characterized by de-pletion of Ba, Sc, Mn, Sr and by enrichment of other rare elements. Major elements and REE were analyzed and the results show that the resource of the sediments are upstream weathering granite. By factor analysis, and corre-lation analysis method, the elements of sediments were analyzed and the results show that the source of sedi-ments are mainly terrigenous detrital minerals, and authigenic accessory mineral like phosphorite and pyrolusite are included, and Ni、Pb、Cu may from the anthropogenic process. The Geo-accumulation Index indicate that Ba is no contamination;relatively the study area has been slightly contaminated by heavy metal V、Cr、Co、Ni、Th、U with the degree of uncontaminated to moderately;elements Cu、Pb、Zn、Mn has the moderately contamination degree;besides, it has been moderately to heavily contaminated by Sc. So the heavy mental Cr、Ni、Cu、Pb、Zn、Mn、Sc polution should be payed more attention to.