重金属单一与复合污染下水稻对铬的富集特征  

Accumulation of Cr in Rice under Single and Combined Pollution

作　　者：梁延鹏[1] 李宗林[1] 张学洪[1] 刘杰[1] 黄海涛[1] 曾鸿鹄[1] LIANG Yanpeng;LI Zonglin;ZHANG Xuehong;LIU Jie;HUANG Haitao;ZENG Honghu(College of Environmental Science and Engineering, Guilin University of Technology//The Guangxi Key Laboratory of Theory and Technology forEnvironmental Pollution Control, Guilin 541004, China)

机构地区：[1]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,广西桂林541004

出　　处：《生态环境学报》2016年第9期1540-1545,共6页Ecology and Environmental Sciences

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)

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0.47~0.69mg·kg-1和0.66~1.60mg·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（1.0mg·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。In order to provide basic knowledge of effect of the target heavy metal on rice, accumulation of heavy metals by rice under sCr single and Cu, Cr, Ni, Cd combined pollution was studied using pot experiments. The results showed that accumulation anddistribution of Cr in plant materials of rice was significantly difference between Cr single and Cu, Cr, Ni, Cd combined pollution. Crmass fraction in different parts of rice at the mature period were in the order: root>leaf>chaff>stem>grain under single pollution.Amount of Cr accumulated was determined to be 56.5%~77.5%, 3.1%~3.5%, 16.8%~31.8%, 2.4%~7.1% and 0.3%~1.0% in root, stem,leaf, chaff and grain, respectively. With increasing Cr mass fraction, the proportion of Cr in roots increased, while a decrease wasobserved in shoots. The distribution of Cr followed the pattern: root>leaf>stem>chaff>grain under combined pollution. Cr enrichmentcoefficients of root and grain all increased, while the enrichment coefficients of other parts remained almost unchanged. The massfraction of Cr in the grains at the mature stage were determined to be 0.47~0.69 mg·kg-1 and 0.66~1.60 mg·kg-1 under single andcombined pollution, respectively , which were all below the national food heavy metal limits hygienic standard (1.0 mg·kg-1, GB 2762-2005) under single pollution. However, under combined pollution, the mass fraction of Cr in 44.4% grains was higher than thenational standard. Results from data analysis indicated that the accumulation and migration of Cr in rice was not only influenced byitself dosage, but also significantly affected by the coexisting elements and doses of Cu, Ni and Cd. A synergistic effect on Cr massfraction in grains was observed in the presence of Cu and Ni, while only a medium dosage of Cd showed a synergistic effect.

关 键 词：铬 单一污染 复合污染 富集 水稻 

分 类 号：X53[环境科学与工程—环境工程]