高海拔区旱地春油菜组织器官重金属迁移特征

Characteristics of heavy metal transport in tissues and organs of spring Brassica napus L. in nonirrigated land

中文关键词:  耕地土壤  重金属  油菜  污染评价

英文关键词:arable soil  heavy metals  Brassica napus L.  pollution assessment

中文摘要:

      目的 对高海拔某工业园区周边耕地土壤及油菜各组织器官中Cd、Cr、Cu、Pb、Ni和Zn的含量进行检测, 并分析土壤-油菜系统中6种重金属元素的分布特征、富集迁移规律。方法 使用全自动石墨炉消解仪对样品进行消解, 使用电感耦合等离子体发射光谱仪(inductively coupled plasma atomic emission spectrometer, ICP-OES), 测定土壤和油菜各组织器官中的6种重金属元素的含量; 结合单因子指数法和内梅罗综合指数法对重金属污染情况进行分析评价; 结果 研究区土壤单项污染指数评价显示重金属Cr、Cu、Pb、Ni和Zn污染等级处于安全水平, Cd污染等级处于重度污染水平。内梅罗综合污染指数评价显示综合污染等级处于中度污染水平; 油菜籽中重金属Cd、Cr、Pb和Ni的污染等级处于安全水平。不同重金属元素在油菜各部位含量差异明显, 农作物生长发育中必需元素Zn和Cu在油菜籽中含量较高, 非必需元素Cd、Ni、Pb和Cr易在油菜果荚中富集。Pb和Cu具有较高的同源性, Cr、Cd和Zn之间的存在拮抗作用, 而拮抗作用可能是影响重金属元素在土壤-油菜各组织器官富集迁移的重要因素。结论 该研究区土壤中Cd污染较为严重, 油菜各组织中重金属污染程度较低, 重金属元素间的拮抗作用可能是影响重金属元素在土壤-油菜各部位富集迁移的重要因素, 油菜各组织器官中重金属的残留对人体及动物健康存在安全隐患, 因此本研究可为大田试验提供方法学基础。

英文摘要:

      Objective To determine the contents of Cd, Cr, Cu, Pb, Ni and Zn in soil and Brassica napus L. tissues and organs around an industrial park at high altitude, and to analyze the distribution characteristics, enrichment and migration rules of 6 kinds of heavy metals in soil-Brassica napus L. system. Methods The samples were digested by automatic graphite furnace digestion apparatus, and the content of 6 kinds of heavy metals in soil and Brassica napus L. tissues were determined by inductively coupled plasma atomic emission spectrometer (ICP-OES). Combined with the single factor index method and Nemerow composite index method to analyze and evaluate the heavy metal pollution. Results The single pollution index of soil in the study area showed that the pollution levels of heavy metals Cr, Cu, Pb, Ni and Zn were in the safe level, and the pollution level of Cd was in the severe level. The comprehensive pollution index of Nemero showed that the comprehensive pollution level was moderate. The pollution levels of heavy metals Cd, Cr, Pb and Ni in rapeseed were at safe levels. The content of different heavy metal elements in different parts of rapeseed were significantly different. The essential elements Zn and Cu were higher in rapeseed, while the non-essential elements Cd, Ni, Pb and Cr were easily enriched in rapeseed pods. Pb and Cu had high homology, and there was antagonism between Cr, Cd and Zn, which might be an important factor affecting the enrichment and migration of heavy metal elements in sore-rape tissues and organs. Conclusion The Cd pollution in the soil is serious, and the heavy metal pollution in the tissues of Brassica napus L. is low. The degree of heavy metal pollution in soil and Brassica napus L. tissues in the study area is low. The antagonism between heavy metal elements may be an important factor affecting the enrichment and migration of heavy metal elements in the soil and various parts of Brassica napus L., and the residues of heavy metal in various tissues and organs of Brassica napus L. have potential safety hazards to human and animal health. Therefore, this study can provide methodological basis for field experiments.