珠三角稻田铜、镉和砷有效性的地球化学机制

发布时间：2018-01-10 01:20

  本文关键词：珠三角稻田铜、镉和砷有效性的地球化学机制　出处：《广西大学》2015年硕士论文　论文类型：学位论文

  更多相关文章： 重金属 理化性质 形态 富集系数 空间变异 水稻

【摘要】：本论文研究区域以广东省珠三角为主,对研究区内采集的191个样品利用GIS、空间分析方法对土壤重金属(Cd、Cu、As)含量、形态和稻米重金属含量以及土壤理化性质进行分析；研究了珠三角地区土壤-水稻系统重金属含量在空间上的分异情况。探讨了土壤理化性质对水稻重金属跟土壤重金属形态,以及土壤重金属形态对水稻重金属关系。本文主要的结论如下：1、珠三角土壤中铜、镉、砷都受不同程度污染,Cd的污染程度超过背景值0.09mg.kg-1的2.5倍。珠三角地区水稻Cd、As的超标率分别为22.51%、21.47%；土壤-水稻系统中铜、镉变异都具有强烈的空间相关性,但As变异还受一部分人为活动因素影响。2、珠三角地区的土壤重金属Cu、Cd、As含量空间分布特征沿着珠江流域高于其他区域；稻米重金属总量空间分布特征显示,Cu、Cd沿着珠江流域浓度高于其他区域。稻米As与土壤中As含量空间分布相对立。3、土壤理化性质与土壤中的重金属形态相关,土壤有机质含量、酸碱度、粘粒含量的增加,土壤中相对稳定形态的重金属含量增加。4、水稻对重金属的富集作用不同,且CdCuAs;土壤中不同形态重金属的生物有效性为HC1CaC12≈NaHAOcDCB。5、土壤中游离态和无定型态铁对水稻不同器官的Cu、Cd吸收具有促进作用,对稻米、稻壳、稻杆对As吸收具有抑制作用。
[Abstract]:In this paper, the Pearl River Delta of Guangdong Province is the main area of study, 191 samples collected in the study area using the GIS-spatial analysis method for the content of heavy metals in the soil. Morphology, heavy metal content of rice and physical and chemical properties of soil were analyzed. The spatial differentiation of heavy metals in the soil-rice system in the Pearl River Delta region was studied. The effects of soil physical and chemical properties on heavy metals and soil heavy metal forms in rice were studied. The main conclusions of this paper are as follows: 1, Cu, CD, as in Pearl River Delta soil are polluted by different degrees. The pollution degree of CD was 2.5 times higher than that of background value of 0.09 mg 路kg ~ (-1). In the Pearl River Delta region, the exceeding rate of CD ~ (2 +) as was 22.51g 路kg ~ (-1) and 21.47%, respectively. The variation of Cu and CD in soil-rice system has strong spatial correlation, but as variation is also affected by some artificial activity factors. The spatial distribution of as content is higher than that of other regions along the Pearl River Basin. The spatial distribution characteristics of total heavy metals in rice indicated that the concentration of as in rice was higher than that in other regions along the Pearl River valley, and the spatial distribution of as in rice was opposite to that in soil. The physical and chemical properties of soil were related to the heavy metal forms in soil. The contents of organic matter, pH, clay and the relative stable form of heavy metals in soil increased by 4. 4. The enrichment of heavy metals in rice was different, and CdCuAs. The bioavailability of different forms of heavy metals in soil was HC1CaC12 鈮，

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