Unravelling transport and deposition mechanisms of virus-like colloids during depth filtration

• Applicant: Professor Dr.-Ing. Matthias Wessling
• Subject Area: Chemical and Thermal Process Engineering
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 455822746

Depth filtration is a cornerstone of membrane filtration processes, playing a critical role in applications such as virus filtration and contaminant removal in wastewater treatment. However, achieving optimized filtration performance requires a deep understanding of particle deposition phenomena and the interplay between fluid flow, filter structures, and particle properties. Advanced technological approaches, such as electric-field-assisted filtration, further promise to revolutionize the field by addressing existing limitations. In the first phase of our project, “Unraveling Transport and Deposition Mechanisms of Virus-Like Colloids During Depth Filtration”, we laid the groundwork by systematically investigating key interactions: particle characteristics (shape, size, and softness), filter properties (inner surface roughness, surface charge, and geometry), and fluid parameters (pH-value). Employing microfluidic model systems alongside real membranes, we uncovered critical insights, many of which have been published in leading journals. Building on this foundation, the second phase of our project aims to address outstanding questions while significantly expanding the scope of our research. We will integrate stimuli-responsive materials into our microfluidic models, enabling dynamic control over filtration conditions. A comprehensive analysis of membrane fouling and coating behavior will be performed, including their mitigation strategies. Furthermore, we will investigate the influence of electric fields on both filtration efficiency and coating stability, leveraging their potential to enhance particle deposition and fouling removal. To achieve these goals, we will employ cutting-edge imaging techniques, including brightfield and fluores- cence microscopy, high-speed imaging, and automated data analysis, to extract critical parameters such as particle streamlines and breakthrough curves. Particle imaging velocimetry (PIV) will provide detailed insights into flow behavior within model membranes, while microscale 3D printing will be used to fabricate realistic three-dimensional filter structures. Novel materials will be explored to produce pores with tailored mechanical and chemical properties, ensuring realistic and applicable results. These experimental data are an essential prerequisite for the complementary work we are conducting in the field of fouling and filtration simulations using CFD-DEM. Financed through our own resources, these two approaches—experimental investigations and computational modeling—synergistically enhance our holistic understanding of the complex physics underlying colloidal filtration. Together, they provide a comprehensive framework for addressing the multifaceted challenges in filtration science.

• DFG Programme: Research Grants