Environment Research Institute, Shandong University, Qingdao 266237, China.
Qingdao SKSS 3D Printing Technology Co. LTD., Qingdao 266111, China.
J Environ Sci (China). 2022 Mar;113:365-375. doi: 10.1016/j.jes.2021.06.025. Epub 2021 Jul 10.
CQDs-doped TiO (C-TiO) has drawn increased attention in recent because of its excellent catalytic performance. Understanding the transport of C-TiO in 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-TiO. The mobility of C-TiO was 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-TiO in porous space. C-TiO mainly 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-TiO deposition 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-TiO in natural porous media.
CQDs 掺杂 TiO（C-TiO）因其优异的催化性能而引起了越来越多的关注。了解 C-TiO 在多孔介质中的迁移对于评估这种新型纳米材料的环境过程是必要的。本研究采用柱实验研究了离子强度（IS）、溶解有机物（DOM）和砂粒大小对 C-TiO 迁移的影响。IS 的增加和砂粒大小的减小抑制了 C-TiO 的迁移，而 DOM 浓度的增加则促进了 C-TiO 的迁移。DOM 的促进效率顺序为腐殖酸（HA）>海藻酸钠（Alg）>牛血清白蛋白（BSA），与它们改变表面电荷的能力顺序一致。通过 3D 打印制备了孔隙网络微模型，以进一步揭示 C-TiO 在多孔空间中的沉积机制和时空分布。由于拦截作用，C-TiO 主要附着在集流器的上游区域。长时间沉积后观察到集流器成熟。DOM 的存在导致 C-TiO 在孔隙网络中的沉积明显减少。HA 导致三种类型的 DOM 中沉积减少最显著，这与柱实验结果一致。这项研究有助于预测 C-TiO 在天然多孔介质中的迁移。
