發(fā)布時(shí)間：2019-03-07 09:26

【摘要】：本研究利用XRF(X射線熒光)和ICP-MS(電感耦合等離子質(zhì)譜儀)分析技術(shù)測(cè)得湘江湘潭段河岸沉積物(XS、ZB)中主、微量元素?cái)?shù)據(jù),通過主成分、逐步回歸及Pearson相關(guān)性分析等方法對(duì)湘江湘潭段河岸沉積物進(jìn)行分析,得到如下結(jié)論:(1)河岸沉積物中Si O2、K2O、Ti O2幾種元素比較穩(wěn)定;Na2O、MnO兩種元素及LOI組分相對(duì)活躍;主量元素具明顯貧Na2O、CaO、MgO等堿性組分而富Fe2O3、MnO等氧化物的化學(xué)組成特征;Al2O3、MgO、P2O5等組分及LOI在所研究的沉積物中有明顯的粒度效應(yīng),TiO2、Fe2O3、MnO、K2O等則無明顯的粒度效應(yīng);主量元素特征顯示沉積物的主要物源是上游的花崗巖風(fēng)化產(chǎn)物。(2)稀土元素特征表明沉積物中:La、Ce、Pr、Nd、Sm等14種稀土元素的平均含量及變異系數(shù)Cv值都表現(xiàn)為自XS到ZB顯著增大;與上地殼、長江沉積物、長江懸浮物等參照體相比,河岸沉積物的REE配分模式曲線為典型的花崗巖配分模式;XS、ZB的均值Ceanom為-0.08-0.10,推斷湘江湘潭段河岸沉積物在沉積時(shí)為缺氧的還原環(huán)境;XS、ZB兩地沉積物的整體沉積速率稍有差異,相比而言ZB可能更接近物源區(qū)。高場(chǎng)強(qiáng)元素分析可知:河岸沉積物中所有的高場(chǎng)強(qiáng)元素垂直變化特征不明顯。(3)重金屬元素統(tǒng)計(jì)結(jié)果顯示:湘江湘潭段河岸沉積物中Zn、Pb兩種元素顯著富集,Mn、Ni、Th、U、V幾種元素中度富集,Ba、Sc、Cr幾種元素?zé)o明顯富集特征。地累積指數(shù)法表明:湘江湘潭段河岸沉積物中普遍存在Zn、Pb、Cu幾種重金屬元素污染危害,多數(shù)元素Ba、Sc、V、Cr、Co、Ni、Th、U不存在污染危害。沉積物的Fe2O3、LOI、∑REE等的含量值,及Eu/Eu*值可作為指示沉積物重金屬污染的地球化學(xué)指標(biāo),對(duì)該段河岸沉積物中重金屬污染有一定的指示作用。(4)主元素與重金屬元素的Pearson相關(guān)性分析顯示,Th、U兩種元素主要賦存于石英等碎屑礦物中,這些微量金屬元素可能主要為自然源,在沉積物中化學(xué)性質(zhì)相對(duì)穩(wěn)定;而Ba、Sc、V、Mn、Co、Cr、Cu、Pb、Zn等重金屬元素則主要賦存于鐵、錳氧化物礦物相中,這些重金屬可能以人為源為主,他們?cè)诔练e物中有一定的化學(xué)活性,可發(fā)生活化遷移。
[Abstract]:In this study, XRF (X-ray fluorescence) and ICP-MS (Inductively coupled Plasma Mass Spectrometer) techniques were used to measure the principal and trace elements in the river sediment (XS,ZB) of Xiangtan section of Xiangjiang River. Stepwise regression and Pearson correlation analysis were used to analyze the riverbank sediments of Xiangtan section of the Xiangjiang River. The conclusions are as follows: (1) Si O _ 2, K _ 2O and TIO _ 2 are relatively stable in the riverbank sediments; The two elements of Na2O,MnO and LOI components are relatively active, and the main elements are characterized by the chemical composition of Fe2O3,MnO and other oxides, which are obviously poor in basic components such as Na2O,CaO,MgO and so on. Al2O3,MgO,P2O5 and LOI have obvious grain size effect in the sediments studied, but TiO2,Fe2O3,MnO,K2O et al have no obvious grain size effect. The characteristics of major elements indicate that the main provenance of sediments is the weathering products of granite upstream. (2) the characteristics of rare earth elements indicate that: La,Ce,Pr,Nd, in sediments The average content and coefficient of variation of 14 rare earth elements, such as Sm and other rare earth elements, increased significantly from XS to ZB. Compared with the reference bodies such as the upper crust, the Yangtze River sediments and the Yangtze River suspended matter, the REE partition model curve of the riverbank sediments is typical granite partition model. The mean Ceanom of XS,ZB is-0.08 ~ 0.10. It is inferred that the sediment in Xiangtan section of Xiangjiang River is a deoxidization environment of anoxia, and the overall deposition rate of sediment in XS,ZB is slightly different, compared with ZB, ZB may be closer to provenance area than that in Xiangtan section of Xiangjiang River. The analysis of high field strength elements shows that the vertical variation characteristics of all high field strength elements in river bank sediments are not obvious. (3) the statistical results of heavy metal elements show that the two elements of Zn,Pb are enriched significantly in the river bank sediments of Xiangtan section of Xiangjiang River, and the Mn,Ni, is found in the sediments of Xiangtan section of Xiangtan River. Some elements of Th,U,V were moderately enriched, while some elements of Ba,Sc,Cr had no obvious enrichment characteristics. The method of land accumulation index shows that several heavy metal elements (Zn,Pb,Cu) are common in the sediments of Xiangtan section of Xiangjiang River, and most of the elements Ba,Sc,V,Cr,Co,Ni,Th,U do not exist pollution hazards. The contents of Fe2O3,LOI, 鈭，

本文編號(hào)：2435988