描绘纳米颗粒附着效率与流体流速之间的关系,Environmental Science & Technology

当前位置： X-MOL 学术 › Environ. Sci. Technol. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

描绘纳米颗粒附着效率与流体流速之间的关系
Environmental Science & Technology ( IF 10.8 ) Pub Date : 2020-10-14 , DOI: 10.1021/acs.est.0c02669
Changwoo Kim ₁ , Kurt D. Pennell ₂ , John D. Fortner ₁

Affiliation

从根本上描述地下纳米颗粒（NP）传输的能力支持环境风险评估和成功的材料应用，包括先进的补救和传感技术。尽管取得了长足的进步，但由于有关流体流速对附着效率的影响的报道相互矛盾，我们对NP沉积行为的理解仍然不完整。为了直接解决这个问题并更准确地描述NP的附着行为，我们开发了一种新颖的协议，使用带有耗散监测的石英晶体微量天平（QCM-D）来分离和单独观察沉积机制（扩散和沉积），从而提供原位，真实的有关粒子扩散（从散装液体到固体表面）的时间信息。通过这种技术，我们已经证实，NPs通过扩散接近的速度随着流速（6.1-106.0μm/ s）的增加而增加（0.8–6.7μm/ s），从而导致NP动能的增加，从而影响沉积过程。此外，在存在与有机表面涂层有关的次要能量最小值的情况下，次要最小沉积量减少，并且次要最小沉积量随流速的增加而增加。沉积在最低限度的NP对流体动能（包括与分离相关的能）的抵抗力相对较高，从而导致观察到的附着效率提高。在一起这项工作不仅描述了一种描述和量化支撑颗粒行为的物理过程的新颖方法，而且还提供了有关定义流速和颗粒附着关系的关键因素的直接测量方法。这种洞察力对于下一代命运和运输模型的准确性非常有价值，尤其是在不利的附着状态下，这是地下材料应用和蕴涵范式的当前和关键需求。

"点击查看英文标题和摘要"

Delineating the Relationship between Nanoparticle Attachment Efficiency and Fluid Flow Velocity

The ability to fundamentally describe nanoparticle (NP) transport in the subsurface underpins environmental risk assessment and successful material applications, including advanced remediation and sensing technologies. Despite considerable progress, our understanding of NP deposition behavior remains incomplete as there are conflicting reports regarding the effect of fluid flow velocity on attachment efficiency. To directly address this and more accurately describe NP attachment behavior, we have developed a novel protocol using a quartz crystal microbalance with dissipation monitoring (QCM-D) to separate and individually observe deposition mechanisms (diffusion and sedimentation), providing in situ, real-time information about particle diffusion (from the bulk liquid to solid surface). Through this technique, we have verified that the approaching velocity of NPs via diffusion increases (0.8–6.7 μm/s) with increasing flow velocity (6.1–106.0 μm/s), leading to an increased NP kinetic energy, thus affecting deposition processes. Further, in the presence of a secondary energy minimum associated with organic surface coatings, secondary minimum deposition decreases and primary minimum deposition increases with the flow velocity. NPs deposited at the primary minimum are relatively more resistant to hydrodynamic energies (including detachment associated energies), resulting in an increase of observed attachment efficiencies. Taken together, this work not only describes a novel method to delineate and quantify physical processes underpinning particle behavior but also provides direct measurements regarding key factors defining the relationship(s) of flow velocity and particle attachment. Such insight is valuable for next-generation fate and transport model accuracy, especially under unfavorable attachment regimes, which is a current and critical need for subsurface material applications and implication paradigms.

更新日期：2020-11-03

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南