土壤污染指标元素钛、锆、钇在吐鲁番地区土壤中的分布及应用

本文根据新疆吐鲁番地区八种母质发育的土壤中Ti、Zr、Y的X射线荧光法分析数据,对这三种元素在土壤中的分布以及用它们之间的比值来判断该地区土壤剖面各层次的母质来源是否相同等问题进行初步探讨。结果表明,不同母质发育的土壤中元素含量有一定差异,而在大多数母质发育的土壤的表、底土间元素含量无明显差异;该地区土壤中zr/Y比和Ti/Zr比可用来判断土壤剖面不同层次的母质来源,两个结果较为一致,对于各层次间元素对比值较接近的剖面,认为是同一母质来源。

DISTRIBUTION AND APPLICATION OF INDEX ELEMENTS TITANIUM, ZIRCONIUM AND YTTRIUM IN SOILS OF TULUFAN, XINJIANG

This paper deals with distribution of titahium, zirconium and yttrium as index elements based on analytical data of soil samples collected from area of Tulufan, Xinjiang. They are derived from eight parent materials. Contents of Ti, Zr and Y were determined by X-ray fluorescence, with Ti and Zr the hightest in soils from andesite, while that of Y is comparatively high in soils from alluviation sediments. No obvious difference is found between Ti, Zr and Y in topsoil and bedsoil, except for Ti and Y in soils from wind deposits, lake sediments and shale.In this paper, origin of parent materials in various layers of a soil profile and enrichment of As in topsoil of the same parent materials were determined based on Ti, Zr and Y existing in parent rocks with anti-weathering minerals. They are left-over soil with original minerals during parent rocks weathering and soils forming. Thus, ratio of various elemental pairs should be close to each other in layers of soil derived from the same parent material. The ratio then can be used in determining whether parent materials in various layers of a soil profile have the same origin if nocorrelation is found between content of the elements in soils from the parent materials. In order to have the results corrected for parent origin determination, correlation coefficients between Ti and Zr, Ti and Y, Zr and Y in soils from various parents were calculated respectively, as 0.294, 0.438 and 0.236. Critical value of correlation coefficient is 0.254, that was evaluated by correlation detection method (a = 0.01). Results showed that ratio of Ti/Zr and Zr/Y can be used in determining whether parent origin is the same for various layers of a soil profile in area of Tulufan. Result obtained was in accord with ratio of Ti/Zr and Zr/Y. There are altogether seventeen profiles that parent origin is the same for various layers in a soil profile. According to the result, enrichment of As was also studied in topsoils of these profiles. Result showed As enrichment in some topsoils of Tulufan area.