重金属单一与复合污染下水稻对铬的富集特征

发布时间：2018-04-06 23:37

本文选题：铬　切入点：单一污染　出处：《生态环境学报》2016年09期

【摘要】：探索重金属单一与复合污染胁迫下水稻富集重金属的规律,以期为科学认识共存重金属对水稻富集目标重金属的影响提供理论依据。采用盆栽试验,研究了重金属Cr单一污染和Cu、Cr、Ni、Cd复合污染下水稻对Cr的富集特征。结果表明,Cu、Cr、Ni和Cd复合污染较Cr单一污染水稻各部位对Cr的富集有明显的差异。单一污染下,Cr在成熟期水稻植株不同部位的质量分数表现为根部叶谷壳茎米粒,根部约占56.5%~77.5%、茎部约占3.1%~3.5%、叶部约占16.8%~31.8%、谷壳约占2.4%~7.1%、籽实约占0.3%~1.0%,且随着Cr投加量的增加,根部Cr所占比例上升,而地上各部位所占比例及相应的吸收富集系数均下降;复合污染下分配规律表现为根部叶茎谷壳米粒,与单一污染相比,根部和米粒的吸收富集系数均有所增大,其余部位的吸收富集系数则呈波动增减。单一和复合污染下米粒Cr的质量分数分别为0.47~0.69 mg·kg-1和0.66~1.60 mg·kg-1,其中复合污染时有44.4%米粒Cr的质量分数超过国家食品卫生标准限值(1.0 mg·kg-1),而单一污染时均没有超标。通过统计分析可知,Cr在水稻植株中富集和迁移除受本身投加量的影响外,还明显受到共存元素Cu、Ni、Cd的影响,而投加量不同则可能会表现出不同的作用,植株部位不同也会表现出不同的作用;其中Cu、Ni均促进Cr向米粒转运,表现为协同作用,同时中浓度Cd也表现为协同作用。
[Abstract]:To explore the rules of heavy metal enrichment in rice under single and complex pollution stress, and to provide a theoretical basis for the scientific understanding of the effect of coexistence of heavy metals on the enrichment of target heavy metals in rice.A pot experiment was conducted to study the enrichment characteristics of Cr in rice under the single pollution of heavy metal Cr and the compound pollution of Cu, Cr, Cr, Ni and CD.The results showed that there were significant differences in Cr enrichment in different parts of rice with single Cr pollution.The proportion of Cr in the root increased, but the proportion of the above ground parts and the corresponding absorption and enrichment coefficient decreased, and the distribution law of the root, leaf, stem and husk grain under the compound pollution was compared with that of the single pollution.The absorption and enrichment coefficients of the roots and grains increased, while those of the other parts increased or decreased.According to the statistical analysis, the enrichment and migration of Cr in rice plants were obviously affected by the amount of the co-existing elements, such as the amount of Cu, Ni and CD, and the different amount of the addition might play a different role in the accumulation and migration of Cr in rice plants.Different parts of the plant also showed different effects, among which Cu Ni promoted the transport of Cr to rice grain, which showed synergistic effect, while the medium concentration of CD also showed synergistic effect.
【作者单位】：桂林理工大学环境科学与工程学院//广西环境污染控制理论与技术重点实验室;
【基金】：广西自然科学基金项目(2015GXNSFBA139199) 广西高等学校高水平创新团队及卓越学者计划项目(002401013001)
【分类号】：X503.231;S511

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