Design of an emergency portable roughing filter using polystyrene beads as media

Roughing filtration is a simple, efficient and chemical free water treatment method for turbidity removal; it can be used as a pre-treatment method prior to slow sand filters or disinfection with chlorine. The main disadvantage of roughing filtration for use in emergency situations is that it uses gravel as a filter medium. Gravel may be unavailable or difficult to transport because of its weight. [Continues.]