Jin Chao, Ren Carolyn L, Emelko Monica B
Department of Civil and Environmental Engineering, University of Waterloo , 200 University Ave W., Waterloo, Ontario N2L 3G1, Canada.
Department of Mechanical and Mechatronics Engineering, University of Waterloo , 200 University Ave W., Waterloo, Ontario N2L 3G1, Canada.
Environ Sci Technol. 2016 Apr 19;50(8):4401-12. doi: 10.1021/acs.est.6b00218. Epub 2016 Apr 7.
It is widely believed that media surface roughness enhances particle deposition-numerous, but inconsistent, examples of this effect have been reported. Here, a new mathematical framework describing the effects of hydrodynamics and interaction forces on particle deposition on rough spherical collectors in absence of an energy barrier was developed and validated. In addition to quantifying DLVO force, the model includes improved descriptions of flow field profiles and hydrodynamic retardation functions. This work demonstrates that hydrodynamic effects can significantly alter particle deposition relative to expectations when only the DLVO force is considered. Moreover, the combined effects of hydrodynamics and interaction forces on particle deposition on rough, spherical media are not additive, but synergistic. Notably, the developed model's particle deposition predictions are in closer agreement with experimental observations than those from current models, demonstrating the importance of inclusion of roughness impacts in particle deposition description/simulation. Consideration of hydrodynamic contributions to particle deposition may help to explain discrepancies between model-based expectations and experimental outcomes and improve descriptions of particle deposition during physicochemical filtration in systems with nonsmooth collector surfaces.
人们普遍认为，介质表面粗糙度会增强颗粒沉积——已有大量但并不一致的这种效应的实例报道。在此，开发并验证了一个新的数学框架，该框架描述了在不存在能量势垒的情况下，流体动力学和相互作用力对粗糙球形收集器上颗粒沉积的影响。除了对DLVO力进行量化外，该模型还改进了对流场剖面和流体动力学阻滞函数的描述。这项工作表明，相对于仅考虑DLVO力时的预期，流体动力学效应可显著改变颗粒沉积。此外，流体动力学和相互作用力对粗糙球形介质上颗粒沉积的综合影响并非相加的，而是协同的。值得注意的是，所开发模型的颗粒沉积预测结果比当前模型的结果更符合实验观察结果，这表明在颗粒沉积描述/模拟中纳入粗糙度影响的重要性。考虑流体动力学对颗粒沉积的贡献可能有助于解释基于模型的预期与实验结果之间的差异，并改进对具有不光滑收集器表面的系统中物理化学过滤过程中颗粒沉积的描述。
