纳米银在饱和多孔介质含水层中迁移主控机理和影响特征

发布时间：2018-05-26 22:13

本文选题：纳米银 + 迁移　；参考：《化工学报》2017年11期

【摘要】：纳米银(AgNP)作为应用最广、生态毒性最强的工程纳米材料之一,一旦进入地下水环境,将引发环境问题。目前,环境因素对纳米银在地下水环境中运移的影响机理尚不清楚。通过室内柱实验,研究了流速(1、2ml·min~(-1))和介质粒径特征(0.605、0.115 mm以及混合粒径的玻璃珠)对纳米银在饱和多孔介质中迁移的影响。研究结果表明纳米银在粒径较大(0.605 mm)的介质中的迁移主要受吸附沉降控制;在小粒径介质中(0.115 mm以及混合粒径玻璃珠),迁移过程同时受吸附沉降和阻塞沉降两种机理的控制,且阻塞效应主要受小粒径部分介质控制。水流速度提高能降低大粒径介质中纳米银颗粒的沉降效率,从而提高其迁移能力。而对于小粒径介质和混合粒径介质,流速提高除了降低纳米银的沉降效率,还能降低阻塞效应和促进尺寸排除效应,不但能更显著地降低纳米银在介质中的衰减,还能提高纳米银在介质中的穿透速度。研究成果对于理解复杂的场地条件下纳米材料的迁移分布动态具有理论价值。
[Abstract]:As one of the most widely used and ecotoxic engineering nanomaterials, AgNPs will cause environmental problems once they enter the groundwater environment. At present, the effect of environmental factors on the migration of silver nanoparticles in groundwater environment is unclear. The effects of flow rate of 1g / 2ml / min ~ (-1) and medium particle size of 0.605 ~ (0.115 mm) and mixed size glass beads on the migration of silver nanoparticles in saturated porous media were studied by column experiments in the laboratory. The results show that the migration of nano-silver in the medium with larger particle size (0.605 mm) is mainly controlled by the adsorption settlement, while in the medium with small particle size (0.115 mm) and the mixed size of glass beads, the migration process is controlled by the two mechanisms of adsorption settlement and blocking settlement at the same time. The blocking effect is mainly controlled by the medium with small particle size. The increase of flow velocity can reduce the sedimentation efficiency of silver nanoparticles in the medium with large particle size and thus improve its migration ability. For the medium with small particle size and mixed particle size, the increase of flow velocity can not only reduce the sedimentation efficiency of silver nanoparticles, but also reduce the blocking effect and the effect of size exclusion, which can not only significantly reduce the attenuation of silver nanoparticles in the medium. It can also improve the penetration speed of silver nanoparticles in the medium. The results are of theoretical value for understanding the migration and distribution dynamics of nanomaterials under complex site conditions.
【作者单位】：四川农业大学环境学院;沈阳大学区域污染环境生态修复教育部重点实验室;
【基金】：国家自然科学基金项目(41471409,41672248) 沈阳市科学事业费竞争性选择项目辽宁省创新团队项目(LT2015017)~~
【分类号】：X131.2

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