摘要
为查明西安市郊菜地土壤和蔬菜重金属污染现状及原因,采用"点对点"采样方法(即同时采集同一地块上的土壤和蔬菜样品),分别采集36个西安市郊菜地土壤和蔬菜样品,分析其Cd、Hg和As 3种重金属元素的质量分数;以单因子污染指数和综合污染指数为评价指标,对其进行污染评价;研究蔬菜与土壤中重金属质量分数之间的相关性。结果表明:(1)西安市郊菜地土壤达到轻度污染水平;其中,Cd为轻度污染,Hg、As质量分数超出警戒线。(2)部分蔬菜重金属质量分数超过国家食品卫生标准。Cd的超标率为27.78%,Hg的超标率为2.78%;但从蔬菜的综合污染指数看,当地的绿叶蔬菜是清洁的。(3)不同蔬菜对Cd和As的富集能力为:芹菜>油菜>小白菜>小青菜,对Hg的富集顺序为:芹菜>小青菜>油菜>小白菜;重金属元素的富集潜势为Cd>Hg>As。(4)土壤全量和有效态Cd、Hg质量分数与蔬菜地上部Cd、Hg质量分数显著正相关。
In order to assess heavy metal pollution status of soil and vegetables in Xi＇an city suburb and their possible reasons,thirty-six coupled samples of soils and vegetables in Xi＇an city suburb were sampled separately with the＂site to site＂sampling method,which meant soil samples and vegetable samples grown on them were collected simultaneously.The mass fraction of heavy metals（Hg,Cd As）were determined and the contaminations of them were assessed with the single factor pollution index and the comprehensive pollution index,and correlation analysis of the heavy metal mass fraction in soil and vegetables was made.The results showed that：（1）Xi＇an city suburb soil was mildly contaminated by Cd etc.,while Hg and As mass fraction didn＇t reach the criterion but exceeded the warning line.（2）Some vegetables＇ heavy metal mass fraction exceeded the criterion of national food hygiene standard.Nearly one third of the vegetable samples＇ Cd mass fraction exceeded the Cd criteri-on,and 2.78%of samples＇ Hg mass fraction exceeded the Hg criterion,while local vegetables were clean and safe according to the comprehensive pollution index.（3）The enrichment capability of Cd and As in different vegetables followed the order：celery〉cole〉chinese cabbage〉brassica chinensis,and the enrichment capability of Hg followed the order of celery〉brassica chinensis〉cole〉chinese cabbage.The accumulation potential of three heavy metals in vegetables followed the order：Cd〉Hg〉As.（4）The Cd and Hg mass fraction in vegetables was positive correlated to total and available Cd and Hg mass fraction in soil.
出处
《西北农业学报》
CAS
CSCD
北大核心
2014年第8期173-181,共9页
Acta Agriculturae Boreali-occidentalis Sinica
基金
农业科研杰出人才及其创新团队培养计划
关键词
镉
汞
砷
有效性
蔬菜
Cd Hg As Availability Vegetable
