更新时间:06-04 上传会员:小婷
分类:工业大学 论文字数:9589 需要金币:1000个
摘 要:本实验采用野外采样系统分析法,研究了某冶炼厂周围长势较好的4种植物五个样品(鬼针草不同距离取了两个样)对重金属(Pb、Zn、Cu和Cd)的吸收与富集作用以及可能的耐性机制。本实验主要是取了冶炼厂周围烟囱附近距离不同的土壤以及土壤上方对应植物,我们主要研究的是土壤里面总重金属的浓度、可溶性重金属的浓度、土壤pH值的测定以及用Tessier连续提取法分别对重金属的可交换态、碳酸盐结合态、铁锰氧化物结合态、有机物结合态和残渣态五个态进行分步提取。然后再对土壤上方对应的植物进行总重金属的提取。对Pb、Zn、Cu和Cd的检测都是用火焰原子吸收光度法。
结果表明:冶炼厂周围的土壤中的重金属,除Cu外,Pb、Zn和Cd的含量已经严重超标,尤其是Cd已经远远超过土壤环境的第三类标准。同时我们还看出,距离烟囱越近,土壤的酸性越强,土壤中所含的重金属量也越多;另外,采用连续提取法对重金属金属提取能够很好的评价土壤中总重金属的浓度,因为用连续提取的方法对Cu、Pb、Zn和Cd的提取率都达到了90%以上。同时,我们还发现,植物中或多或少能够富集一定量的重金属,这些都为进行土壤修复提供了一定的理论基础。对土壤的研究能够确定土壤中重金属的种类及其含量,而在对植物进行分析的过程中,我们得出了植物具有富集重金属的能力,这就为现在很有发展前景的植物修复提供了理论基础。
关键词:污染;土壤;重金属
ABSTRACT:The present study, field sampling system analysis to study the good growing around a smelter of five samples of 4 species (Bidens two samples taken at different distances) to heavy metals (Pb, Zn, Cu and Cd) uptake And accumulation and possible tolerance mechanisms. This experiment is focused around the chimney near the smelter to take a different soil and soil from the top of the corresponding plants, we study the total concentration of heavy metals within the soil, the concentration of soluble heavy metals, the determination of soil pH, and Tessier sequential extraction method was used Heavy metal exchangeable, carbonate, iron and manganese oxides, organic matter bound and residual states were five-step extraction. Then on top of the corresponding soil total heavy metal extraction plants. The Pb, Zn, Cu and Cd, detection is by flame atomic absorption spectrophotometry.
The results showed: the soil around smelters in the metals, except Cu addition, Pb, Zn and Cd contents have been seriously overweight, in particular soil Cd has been far more than the third category of standards. We also see that the closer the distance the chimney, the stronger the acidity of the soil, soil heavy metals contained in the more; In addition, the use of sequential extraction of heavy metals in the evaluation of metal extraction can be a very good total concentration of heavy metals in soil, Because the method of extraction with continuous Cu, Pb, Zn and Cd extraction rate reached 90% or more. We also found that plants more or less enriched in a certain amount of heavy metals, which are for the purpose of soil remediation provides a theoretical basis. Research to determine the soil types and soil content of heavy metals, and in the process of plant analysis, we come to accumulation of heavy metals in plants with the capacity, which is now promising to provide a phytoremediation Theoretical basis.
Keywords: pollution; soil; heavy metal