• 中文核心期刊
  • CSCD来源期刊
  • 中国科技核心期刊
  • CA、CABI、ZR收录期刊

镉污染下稻谷不同部位重金属含量及迁移特征

Contents and Transport of Heavy Metals in Grain Parts of Rice Grown on Cd-Contaminated Soil

  • 摘要: 为了解镉污染土壤中稻谷各部位重金属的含量及其迁移特征,以闽西矿区周边种植的水稻为研究对象,测定稻谷各部位的Cd、Pb、Cu、Zn含量,分析这4种重金属在稻谷各部位的分布及迁移规律,结果表明:在无镉污染、轻度镉污染、中度镉污染、重度镉污染环境中种植的水稻,其Cd、Cu、Zn在稻谷中不同部位的含量基本呈糠粉>糙米>精米>稻壳的趋势,即镉污染及其程度不会影响Cd、Cu、Zn在稻谷中不同部位的分布,而Pb在稻谷各部位的含量呈稻壳>糠粉>糙米>精米或糠粉>稻壳>精米>糙米的趋势;稻壳中的Cd较易被迁移到糙米中,糙米中的Pb、Cu、Zn极易积累到糠粉中,而糠粉中积累的Cd、Pb、Cu、Zn较难被迁移到精米中;糙米从去掉糠粉加工成精米的过程中,Cd、Pb、Cu、Zn含量最大程度可分别减少70.2%、95.0%、97.1%和81.4%;重金属在稻谷各部位间的迁移能力与各部位重金属含量有一定的相关性。说明糠粉对这4种重金属有较强的吸收力,稻谷加工过程尽可能去除糠粉部位可以减少食用部分的重金属含量。

     

    Abstract: Contents and transport of heavy metals in various parts of a grain from the rice grown on Cd-contaminated soil were determined. The contents of Cd, Pb, Cu and Zn in specimens collected from the mining regions in western Fujian were analyzed to study the distribution and transport characteristics of these heavy metals in the parts of the grain. The results showed that although the metal distribution was not affected by the severity of soil pollution, the Cd, Cu or Zn contained in a grain increased in the order of:bran > brown rice > milled rice > hull, and, the Pb in the order of:hull > bran > brown rice > milled rice or bran > hull > milled rice > brown rice. There seemed a significant correlation between the contents and transport of heavy metals in the grains. And, the bran appeared to absorb the heavy metals more readily than other tissues, as it was easier for Cd in the hull to transport to the brown rice grains, or Pb, Cu and Zn in brown rice to the bran; but more difficult for Cd, Pb, Cu and Zn in the bran to move to the milled grains. As a result, the contents of Cd, Pb, Cu and Zn in the grains could be maximally reduced by 70.2%, 95.0%, 97.1% and 81.4%, respectively, through the milling process with the removal of bran, thereby, an improvement for the safety of rice consumption.

     

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