Membrane microfiltration is used widely, from processing small particles and colloids, to biological applications such as protein precipitates and microorganisms. Porous membranes designed with specific porosity, surface area, pore size distribution, and permeability play critical roles in achieving health, environmental, or engineering performance goals, when sieving is required. 3D micro-imaging and image-based simulation solve long standing challenges in filtration and fluid management industry.