| 涂汉,吴攀,韩志伟,曹星星,张水.贵州草海上覆水与沉积物中砷的分布特征及扩散通量估算[J].农业环境科学学报,2016,35(5):963-968. |
| 贵州草海上覆水与沉积物中砷的分布特征及扩散通量估算 |
| Distribution and diffusion flux of arsenic in sediment and overlying-water of Lake Caohai, Guizhou Province |
| 投稿时间：2015-10-24 |
| DOI：10.11654/jaes.2016.05.021 |
| 中文关键词: 草海 砷 沉积物 孔隙水 扩散通量 |
| 英文关键词: Caohai arsenic sediment pore water diffusion flux |
| 基金项目:贵州大学研究生创新基金项目(研理工2015064) |
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| 中文摘要: |
| 对草海不同区域沉积物上覆水及孔隙水、附近河流和雨水中砷的含量与分布特征进行了分析,并利用一维孔隙水扩散模型估算了砷在沉积物-水界面的扩散通量。结果表明:草海出口砷含量为1.59 μg·L-1,明显高于流入草海的水体端元(平均值0.32 μg·L-1)和雨水(0.37 μg·L-1)中砷浓度;草海上覆水中砷的空间分布表现为挺水植物区(2.99~3.45 μg·L-1)>沉水植物区(1.79~2.34 μg·L-1),垂直分布上无明显变化,挺水植物区上覆水体中的砷以As(Ⅲ)(H3AsO3)形态存在,沉水植物区上覆水体中的砷以As(Ⅴ)(HAsO42-)形态存在;而沉积物和孔隙水中总砷含量垂直方向上波动较大,规律与上覆水相似,均表现为挺水植物区>沉水植物区,其中挺水植物区沉积物砷含量为19.86~36.45 mg·kg-1,平均值27.84 mg·kg-1,沉水植物区沉积物砷含量为13.05~32.32 mg·kg-1,平均值19.79 mg·kg-1;草海挺水植物区和沉水植物区三处取样点在沉积物-水界面的扩散通量分别为73.84 μg·m-2·d-1和18.99、11.45 μg·m-2·d-1,均表现为沉积物孔隙水中的砷向上覆水释放,揭示沉积物可能是草海水体中砷重要的输入源。 |
| 英文摘要: |
| This paper investigated the distribution and concentration of arsenic in overlying water and sediment pore water of Caohai as well as the nearby rivers and rainwater in different areas. Utilizing one-dimensional pore water diffusion model, we estimated arsenic diffusion flux across the sediment-water interface. Results indicated that arsenic concentrations at the Caohai exit was 1.59 μg·L-1, obviously higher than at the entry of Caohai(averagely 0.32 μg·L-1) as well as rainwater(0.37 μg·L-1). The spatial distribution of arsenic concentrations in the overlying water was as follows:emergent plant zone(2.99~3.45 μg·L-1)> submerged plant zone(1.79~2.34 μg·L-1). The arsenic in the overlying water existed as H3AsO3 form in emergent plant zone but as HAsO42- form in submerged plant zone. The total arsenic concentrations in sediments and pore water showed large vertical variation and were emergent plant zone>submerged plant zone. The arsenic in the sediments in emergent plant zone was between 19.86 mg·kg-1 and 36.45 mg·kg-1, with average value of 27.84 mg·kg-1, while in submerged plant zone arsenic concentrations ranged from 13.05 mg·kg-1 to 32.32 mg·kg-1, averaging 19.79 mg·kg-1. The diffusion flux across the sediment-water interface in emergent plant and submerged plant zons were 73.84 μg·m-2·d-1 and 18.99~11.45 μg·m-2·d-1, respectively, showing that arsenic stored in sediment pore water released into the overlying water and that sediment might thus be significant source of arsenic in Lake Caohai water. |
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