| 摘要: |
| 河口沉积物在陆源砷向海洋输送过程中具有源和汇的双重作用, 分析砷在河口沉积物中的存在形态和分布特征对于掌握砷的毒理效应和污染评价具有重要意义。通过野外调查和样品采集, 对秦皇岛典型河流河口沉积物中砷的质量比进行了测定, 并采用Tessier 五步连续提取法对砷在沉积物中的存在形态进行了提取分析。结果表明, 汤河河口表层沉积物中砷的质量比为35.73~46.63 mg/kg, 戴河河口表层沉积物中砷的质量比为13.60~16.00 mg/kg, 汤河河口沉积物砷含量明显高于戴河河口。总砷含量随沉积深度的增加而有降低的趋势。各形态砷在沉积物中的分布特征基本一致, 即以残渣态为主,占其总量的87%以上, 其他各形态相对含量较小, 其中可利用性最强的可交换态含量最小, 平均为1.04 %。各形态砷分布与沉积物的pH 和有机质含量有一定的相关关系, pH 和有机质含量的改变将会影响砷的形态分布特征。 |
| 关键词: 河口沉积物 总砷 砷形态 分布特征 |
| DOI： |
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| 基金项目:国家地质实验测试中心基本科研业务费专项经费资助(201011CSJ09); 中国地质科学院岩溶地质研究所基本科研业务费项目(2012012); 秦皇岛科技局科技支撑计划项目(201101A218) |
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| Distribution characteristics of arsenic species in Qinhuangdao estuarine sediments |
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| Abstract: |
| Estuarine sediments play an important role in the land-sea transport process and may be the source or sink of arsenic. Arsenic concentration of Qinhuangdao estuarine sediments was determined and Tessier five-step sequential extraction was used to analyze the species of arsenic. The results showed that the arsenic concentration in the Tang River estuarine was higher than that in the Dai River estuarine. The arsenic concentration in surface sediments of the Tang River was 35.73～46.63 mg/kg, while that in the Dai River was only 13.6～16.00 mg/kg. The total arsenic concentration decreased with increase of depth. The distribution characteristics of arsenic species in sediment were almost same, i.e., the majority of species was residual fraction (over 87%) and the contents of other forms of arsenic were lower than residual form. The exchangeable species of arsenic were the smallest with an average percentage of 1.04%. Arsenic species, pH and organic matter concentration have a certain correlation. The change of pH and organic matter concentration would affect the distribution of arsenic species. |
| Key words: estuarine sediments total arsenic arsenic species distribution characteristics |
