干旱区绿洲土壤中胡萝卜对Pb-Zn污染的响应及重金属累积特征  

Lead and zinc migration characteristics in the farmland soil-carrot system under Pb-Zn stress in arid areas' oases soil

作　　者：庞瑜[1] 赵转军[1] 南忠仁[1] 王兆炜[1] 

机构地区：[1]甘肃省环境污染预警与控制重点实验室兰州大学资源环境学院,兰州730000

出　　处：《干旱区资源与环境》2017年第6期166-172,共7页Journal of Arid Land Resources and Environment

基　　金：中央高校基本科研业务费专项资金(lzujbky-2015-144223000-861952);国家自然科学基金项目(No.51178209)资助

摘　　要：以干旱绿洲土壤为研究对象,采用盆栽实验探究外源Pb-Zn复合胁迫下,重金属对胡萝卜生长形态的影响及两种元素在研究区土壤-胡萝卜中的迁移转化特征。结果表明:随着胁迫浓度的增大,胡萝卜叶长随之降低,根长变化不明显,干重变化呈"低促高抑"态势。从两种重金属的积累特征看:胡萝卜对Pb、Zn的富集系数(BCF)均小于1,迁移系数(TF)均大于1,即两种重金属在整个迁移系统中的运移界面主要位于根-叶之间,且根-叶间迁移能力大小为:Zn>Pb。通过对比分析发现两种元素交互作用为:Pb对于Zn的富集和迁移均产生拮抗作用;Zn的共存对Pb的迁移是协同作用,但对其富集作用的影响表现为:低浓度拮抗,高浓度协同。Pot experiment were conducted on carrot grown in oasis soil under combined stress of lead and zinc, to study the effect of heavy metal combined pollution on carrot growth as well as the enrichment and migration of heavy metals in carrot. The result showed that the concentrations of the heavy metals in carrot are positively correlated with the concentrations of the two kinds of the heavy metals in soil. The promoting effect on the carrot dry biomass was shown in the low concentration treatments, and the carrot roots＇ dry biomass varied from - 11.97 % to 173.26%, leave＇ s dry biomass varied from - 22.9% to 82.49%. At the same time, both of the two kinds of metals＇ BCF values never exceeded one. But the TF values were never below one. The main migration between the roots and leaves showed Lead was more inactive than zinc in general. While the two kind of heavy metals apply to the carrot simultaneously, lead decreased zinc＇ s BCF values and TF values, but zinc increased the TF values of the lead. And TF values of lead were increased while under low zinc concentration, but under high concentration of zinc it showed opposite trend.

关 键 词：重金属 PB Zn 复合污染 迁移转化 绿洲土壤 

分 类 号：X171.5[环境科学与工程—环境科学]