The transport and retention of CQDs-doped TiO2 in packed columns and 3D printed micromodels.
The transport and retention of CQDs-doped TiO2 in packed columns and 3D printed micromodels.
复制标题
CQD 掺杂 TiO2 在填充柱和 3D 打印微模型中的传输和保留。
DOI：
10.1016/j.jes.2021.06.025
复制
发表时间：
2021
影响因子：
6.9
通讯作者：
Wei Jiang
中科院分区：
文献类型：
--
作者：
Tao Sun;Jian Song;Zhen Liu;Wei Jiang
CQDs掺杂的TiO 2（C-TiO 2）由于其优异的催化性能，近年来受到了广泛的关注。了解C-TiO 2在多孔介质中的迁移规律对于评价这种新型纳米材料的环境过程是必要的。本文采用柱实验研究了离子强度（IS）、溶解性有机物（DOM）和沙粒粒径对C-TiO 2运移的影响。增加IS和减小沙粒粒径抑制了C-TiO 2的迁移，增加DOM浓度则促进了C-TiO 2的迁移。DOM的促进作用大小依次为腐殖酸（HA）>海藻酸钠（Alg）>牛血清白蛋白（BSA），这与其改变表面电荷的能力大小顺序一致。通过3D打印技术制备孔隙网络微观模型，进一步揭示C-TiO 2在多孔空间的沉积机理和时空分布。C-TiO 2主要吸附在捕收剂的上游区域，主要是由于截留作用。在长时间沉积后观察到捕收剂成熟。DOM的存在使C-TiO 2在孔网络中的沉积量明显减少。在3种DOM中，HA对沉积的抑制作用最显著，这与柱试验结果一致。该研究有助于预测C-TiO 2在天然多孔介质中的迁移行为。
CQDs-doped TiO2(C-TiO2) has drawn increased attention in recent because of its excellent catalytic performance. Understanding the transport of C-TiO2in porous media is necessary for evaluating the environmental process of this new nanomaterial. Column experiments were used in this study to investigate ionic strength (IS), dissolved organic matter (DOM) and sand grain size on the transport of C-TiO2. The mobility of C-TiO2was inhibited by the increased IS and decreased sand grain size, but was promoted by the increased DOM concentration. The promotion efficiency of DOM ranked as humic acid (HA) > alginate (Alg) > bovine serum albumin (BSA), which was in the same order as their ability to change surface charges. The micromodels of pore network were prepared via 3D printing to further reveal the deposition mechanisms and spatial/temporal distribution of C-TiO2in porous space. C-TiO2mainly attached to the upstream region of collectors because of interception. The collector ripening was observed after long-time deposition. The existence of DOM caused visible decrease of C-TiO2deposition in the pore network. HA caused the most remarkable reduce of deposition in the three types of DOM, which was consistent with the column experiment results. This research is helpful to predict the transport of C-TiO2in natural porous media.