污灌区小麦重金属镉污染及其空间分布研究.doc

文档介绍：
污灌区小麦重金属镉污染及其空间分布研
究#
陈涛*
5
10
(西北农林科技大学资源环境学院,陕西杨凌 712100)
摘要:本研究利用地统计学分析了污水灌溉条件下镉(Cd)在小麦不同部位的累积状况及
其空间分布特征。结果表明,由于长期污灌,土壤大量富集重金属 Cd,导致其在小麦不同
部位累积,根、茎叶、籽粒平均 Cd 含量分别达到 mg kg-1、 mg kg-1、 mg kg-1,
按其平均累积量大小排序为根>茎叶>籽粒;小麦籽粒 Cd 含量、茎叶 Cd 含量均与土壤 Cd
之间呈幂函数关系,而根部 Cd 含量与土壤 Cd 之间为线性关系;整个研究区,不同小麦部
位的 Cd 含量总体表现为东高西低的空间分布规律,这与土壤 Cd 含量的分布格局具有极高
相似性,土壤 Cd 污染已影响到小麦质量安全生产,应引起环保部门的高度重视。
关键词:小麦重金属污染;污灌;镉;空间分布
中图分类号:
15
Wheat Cd Pollution and Spatial Distribution in Sewage
Irrigation Area
CHEN Tao
(College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi
20
25
30
35
712100)
Abstract: In a typical sewage irrigation area, 52 wheat samples were collected to determine
cadmium (Cd) concentration. The Cd pollution status and its spatial distributions in different
wheat parts were identified based on geostatistics. The results showed that the average Cd content
of wheat grain, stem leaf, and root was mg kg-1, mg kg-1, and mg kg-1,
respectively, which followed the order: Cd in wheat grain>Cd in stem and leaf>Cd in root. Based
on regress analysis, the power function model was found between wheat grains Cd content, stem
leaf Cd content and soil total Cd content; whereas the linear model between wheat root Cd content
and soil Cd was identified. In the study area, a gradually declining trend of Cd cont