广西北部湾地区表层土壤重金属分布特征及其影响因素研究

发布时间：2018-05-11 01:33

本文选题：重金属 + 分布特征　；参考：《中国地质大学(北京)》2016年硕士论文

【摘要】：选取广西北部湾地区表层土壤中重金属元素作为研究对象,采集了7327件土壤样品和400件岩石样品,在分析土壤重金属元素含量水平和空间分布特征基础上,讨论成土母岩、风化作用、主量元素、有机碳(SOC)和pH对土壤重金属元素的影响,并阐述了这些影响因素间的主次关系。主要得出如下结论:1.除了Ni、Cu和Zn外,其他元素平均含量总体上高于全国背景值,其中As、Hg和Cd元素的平均含量是全国背景值的1.3倍以上。2.各重金属元素的高值区、中值区和低值区具有较好的耦合性,高值区主要分布于研究区的西北部、东北部和中部,中值区主要分布在研究区的中部,低值区主要分布在研究区的中北部以及南部。3.成土母岩中重金属元素含量大小顺序表现为碎屑岩中酸性岩碳酸盐岩,土壤中重金属含量大小顺序为碳酸盐岩土壤(灰岩、白云岩)第四系沉积碎屑岩土壤(砂岩、砾岩、页岩)中酸性岩土壤,二者表现出一定的负相关性,表明成土母岩对土壤重金属元素的影响作用不明显。4.成土母岩发、成土作用与重金属元素关系表明,成土过程特别是风化作用对土壤重金属的影响强于成土母岩的影响。5.含Al矿物、含Fe矿物、SOC和pH是重金属元素重要影响因素,而含Ca、K、Na和Mg的矿物对重金属的吸附作用不明显,石英不利于重金属的富集。
[Abstract]:7327 soil samples and 400 rock samples were collected from the surface soil of Beibu Gulf area, Guangxi. Based on the analysis of soil heavy metal content level and spatial distribution characteristics, the parent rocks were discussed. The effects of weathering, major elements, organic carbon soc) and pH on the heavy metal elements in soil were discussed, and the primary and secondary relationships between these factors were discussed. The main conclusion is as follows: 1. With the exception of Cu and Zn, the average contents of other elements were generally higher than the national background values, and the average contents of Ash Hg and CD were 1.3 times of the national background values. The high value region, the middle value region and the low value region of each heavy metal element have good coupling. The high value region is mainly distributed in the northwest, northeast and middle of the study area, and the median region is mainly distributed in the middle of the study area. The low value region is mainly distributed in the north and north of the study area. The order of heavy metal contents in parent rocks is carbonate rock in acid rock, carbonate rock in carbonate rock (limestone, dolomite) in Quaternary sedimentary clastic rock soil (sandstone, conglomerate). There was a negative correlation between them, which indicated that the effect of parent rock on heavy metal elements was not obvious. 4. The relationship between parent rock formation, soil-forming process and heavy metal elements indicates that the influence of soil-forming process, especially weathering, on soil heavy metals is stronger than that of soil-forming parent rock. Al-bearing minerals, Fe-bearing minerals such as SOC and pH are important factors affecting heavy metal elements, while minerals containing CaOK Na and mg have no obvious adsorption on heavy metals, and quartz is not conducive to the enrichment of heavy metals.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S153

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