Membrane filtration.
https://www.emergency-wash.org/water/en/technologies/technology/membrane-filtration
👉🏼 PDF: https://app.box.com/s/ezoq82p6veulyzg9t66k7h9nu4f8ljmw _ Household Membrane Filters generally use ultrafiltration (UF) or microfiltration (MF) membranes as flat sheet or hollow fibre modules. Water is filtered by gravity or manual pumping. Particles, colloids, protozoa, bacteria and viruses are retained on the membrane surface. The removal performance depends on the pore size of the membrane and its manufacturing quality.