Transport, retention, and size perturbation of graphene oxide in saturated porous media: effects of input concentration and grain size.
Transport, retention, and size perturbation of graphene oxide in saturated porous media: effects of input concentration and grain size.
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DOI：
10.1016/j.watres.2014.09.025
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发表时间：
2015
期刊：
影响因子：
12.8
通讯作者：
Yuanyuan Sun;B. Gao;S. Bradford;Lei Wu;Hao Chen;Xiaoqing Shi;Jichun Wu
中科院分区：
文献类型：
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作者：
Yuanyuan Sun;B. Gao;S. Bradford;Lei Wu;Hao Chen;Xiaoqing Shi;Jichun Wu
准确预测氧化石墨烯（GO）在多孔介质中的命运和运输对于评估其环境影响至关重要。在这项工作中，砂柱实验确定了输入浓度和粒度对氧化石墨烯在饱和多孔介质中的输运、滞留和粒径扰动的影响。氧化石墨烯在细砂柱中的迁移率随粒径的减小而减小，在所有测试条件下，氧化石墨烯几乎全部保留在细砂柱中。这一结果可以用胶体过滤和XDLVO理论来解释。输入浓度也会影响氧化石墨烯在砂柱中的保留和运输，因为“阻塞”机制降低了颗粒的保留率。通过色谱柱后，氧化石墨烯的平均粒径急剧增加。此外，随着移动距离的增加，砂土中氧化石墨烯的粒径也有所增加。这些结果表明，通过多孔介质的运输诱导了氧化石墨烯的聚集。基于平流-色散方程的数学模型与反映阻塞效应的二级动力学相结合，较好地模拟了实验数据。
Accurately predicting the fate and transport of graphene oxide (GO) in porous media is critical to assess its environmental impact. In this work, sand column experiments were conducted to determine the effect of input concentration and grain size on transport, retention, and size perturbation of GO in saturated porous media. The mobility of GO in the sand columns reduced with decreasing grain size and almost all GO were retained in fine sand columns for all of the tested conditions. This result can be explained with colloid filtration and XDLVO theories. Input concentration also influenced the retention and transport of GO in the sand columns because of the ‘blocking’ mechanism that reduces the particle retention rate. After passing through the column, average GO sizes increased dramatically. In addition, the sizes of GO retained in the sand also increased with travel distance. These results suggested that transport through the porous media induced GO aggregation. A mathematical model based on the advection–dispersion equation coupled with the second-order kinetics to reflect the blocking effect simulated the experimental data well.