State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; Kunming Institute of Eco-Environmental Sciences, Kunming, 650032, China.
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; Institute of Water Environment Research, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
Chemosphere. 2022 Nov;307(Pt 4):136070. doi: 10.1016/j.chemosphere.2022.136070. Epub 2022 Aug 16.
Black carbon (BC) and humic acid (HA) have been proposed to dominate the sorption behavior of phenanthrene in sediment. Nevertheless, little is known about the sorption mechanism that related to particle-scale by spiking of BC and HA in sediment particle size fractions. In this study, sorption isotherms for phenanthrene were determined in four particle-size sediment fractions (<2 μm, 2-31 μm, 31-63 μm and >63 μm) that amended with BC and HA, or not. The fitting results by Freundlich model indicated that the sediment particle size fractions amended with BC increased the sorption capacity and affinity for phenanthrene. Sediment coarser size fractions (31-63 μm and >63 μm) by spiking of BC contributed higher to sorption capacity factor (K) and nonlinearity factor (n) than the finer size fractions (2-31 μm and <2 μm). By contrast, the sediment particle size fractions amended with HA enhanced the sorption distribution coefficient (K), but reduced the sorption affinity for phenanthrene. All these phenomena are obviously affected by the distribution of heterogeneous organic matter that related to sediment particle-scale. Results of this work could help us better understand the impact of increased BC and HA content in sediments on the sorption of hydrophobic organic pollutants (HOCs) and predict the fate of HOCs in offshore sediments due to tidal action.
黑碳 (BC) 和腐殖酸 (HA) 被认为是控制沉积物中菲吸附行为的主要物质。然而，关于相关颗粒尺度的吸附机制，即通过在沉积物颗粒大小分数中添加 BC 和 HA 来研究这一机制，目前还知之甚少。在这项研究中，通过向 <2 μm、2-31 μm、31-63 μm 和 >63 μm 四个颗粒大小分数的沉积物中添加或不添加 BC 和 HA，确定了菲的吸附等温线。由 Freundlich 模型拟合的结果表明，添加 BC 的沉积物颗粒大小分数增加了对菲的吸附容量和亲和力。与较细的颗粒大小分数（2-31 μm 和 <2 μm）相比，添加 BC 的较粗颗粒大小分数（31-63 μm 和 >63 μm）对吸附容量因子（K）和非线性因子（n）的贡献更高。相比之下，添加 HA 的沉积物颗粒大小分数提高了吸附分配系数（K），但降低了对菲的吸附亲和力。所有这些现象都明显受到与沉积物颗粒尺度相关的异质有机物分布的影响。这项工作的结果可以帮助我们更好地理解沉积物中增加的 BC 和 HA 含量对疏水性有机污染物 (HOCs) 吸附的影响，并预测潮汐作用下近海沉积物中 HOCs 的归宿。
