第 50 卷 第 3 期
2014 年 6 月
兰 州 大 学 学 报(自然科学版)
Journal of Lanzhou University (Natural Sciences)
Vol. 50 No. 3
Jun. 2014
文章编号: 0455-2059(2014)03-0431-06
白银黄灌农业区不同土层重金属赋存形态及其
风险评价
刘白林, 马新旺, 朱赛勇, 艾世伟, 张文雅, 张迎梅
兰州大学 生命科学学院, 兰州 730000
摘 要: 采用改进后的 BCR 四步连续提取 法, 分析了甘肃省白银市黄灌 农业区农田土壤 5 个土层重金属 Cd,
Cu, Pb, Zn 的 4 种赋存形态, 并依其污染指数和 潜在生态危害指数, 评价了白银黄灌农业区各 层土壤中重金
属 的 污染程 度 及其 潜 在生态 危 害. 结 果 表明: 白银 黄 灌农 业 区土壤 重 金 属 各 形 态质 量 分 数(包 括 重 金 属 总
量)均在表层中达到最大值, 而在中层最低. 各层土壤中 Cu 以残渣态为主, 占比为 72.83%~91.80%. 除表层外,
Pb, Zn 也以残 渣态为主, 占比分别为 57.14%~70.19%, 69.56%~80.95%, 而 Cd 各 形态在不同土层中没有呈 现
规律性分 布. 根 据污染 水 平, 各层土壤中 4 种重金属的污染程 度 顺 序 均 为Cd > Pb > Zn > Cu. 根据 潜 在 生 态
危害, 各层土壤中 4 种 重金属的潜在生态危害顺 序均为Cd > Pb > Cu > Zn, 其中 Cd 的污染 程度最高, 潜 在生
态危害最 强, 表层尤其突 出. 综合本研究 结果, 白银市 黄灌农业区土壤 Cd 污染严重, 亟需整治以减小其对当
地农作物及居民的潜在危害.
关键词: 土壤重金属; 赋存形态; 元素污染指数; 潜在生态危害指数
中图分类号: X503.1; X826 文献标识码: A doi: 10.13885/j.issn.0455-2059.2014.03.021
Speciations and risk ass essment of heavy metals in different
laye rs of lands irrigated by the Yellow River i n Baiyi n
LIU Bai-lin, MA Xin-wang, ZHU Sai-yong, AI Shi-wei, ZHANG Wen-ya,
ZHANG Ying-mei
School of Life Sciences, Lanzhou University, Lanzhou 730000, China
Abstract: The chemical speciations of heavy metals (Cd, Cu, Pb and Zn) in five layers of irrigated lands of the
Yellow River in Baiyin were analyzed by means of the modified BCR-sequential extraction procedure. Elemental
contamination index and integrate ecological risk index were employed to assess the contamination degree and
potential ecological risks of heavy metals. The results showed that th e mass fractions of heavy metals’ specia-
tions in the surface layer of the studied area reached the highest level, while those in the middle layer hit the
lowest point. Besides, Cu in different layers mainly existed in residual form, accounting for 72.83%~91.80%. Pb
and Zn were also chiefly presented in residual form in different layers, except for the surface layer, representing
57.14%~70.19% and 69.56%~80.95% respectively. Moreover, speciations of Cd did not regularly distribute in
different layers. According to elemental contamination ind ex and integrate ecological risk index, the contamina-
tion degree and the potential ecological risk of detected heavy metals was Cd>Pb>Zn>Cu and Cd>Pb>Cu>Zn
respectively, of which Cd in the surface layer was the highest. I n conclusion, Cd pollution in Baiyin farmland
soil is rather severe. Therefore, it is suggested that strict measures must been taken to diminish the potential
hazard of Cd to local crops and inhabitants.
Key words: soil heavy metal; chemical speciation; elemental contamination index; integrate ecological risk
index
收稿日期: 2013-10-25; 修回日期: 2013-12-09
基金项目: 国家自然科学基金项目 (41171391)
作者简介: 张 迎 梅 (1963-), 女, 山 西 临 汾 人, 教 授, 博 士 研 究 生 导 师, e-mail: ymzhang@lzu.edu.cn, 研 究 方 向 为 遗 传 毒 理 学 与
生态毒理学, 通信联系人.