Rapid Sand Filtration.
https://www.emergency-wash.org/water/en/technologies/technology/rapid-sand-filtration
👉🏼 PDF: https://app.box.com/s/k24tatjbkwhp7a06ovspjs48m5cala0o ____ Rapid Sand Filters use coarse sand as a filtration medium to remove fine suspended solids from water with varying levels of turbidity (or ‘muddiness’). It is a pre- treatment step prior to a final disinfection process, such as Chlorination T.6 , and can be used in all phases of an emergency.