Influence of the filter grain morphology on separation efficiency in dielectrophoretic filtration

Abstract

Recovery of noble materials from waste is essential for industries around the globe. Dielectrophoretic (DEP) filtration, an electrically switchable particle separation technique, can be applied to tackle this challenge. It is highly selective regarding particle size, material, or shape. Expanding the scope of DEP towards high throughput and improving the trapping efficiency are vital to make DEP a viable robust alternative to conventional separation methods. DEP filtration works by selective immobilisation of particles in a porous medium by the action of an inhomogeneous electric field. The field inhomogeneity comes from scattering an electric field at the phase boundary between the particle suspension and the filer surface. In this article, we show how the filter structure affects the DEP separation. We study fixed bed filters of three different grain types and find that the morphology of the grains highly influences the DEP filter efficiency. Specifically, grains with irregular surface structure and high perceived angularity show high separation efficiency. We believe insights into the design of DEP filtration will pave the way towards its application in, e.g., the recovery of valuable materials from electronic waste dust.

Influence of the filter grain morphology on separation efficiency in dielectrophoretic filtration

“…The 3D µCT images of three different samples (glass beads mesh 250, sand mesh 250 and sand mesh 355) and their segmented porous structures are shown in Figure 3 (details for segmentation and analysis can be found in Section S6 and the online repository [33]).…”