Which materials are commonly used in granular media filters?

Granular media filters utilize a variety of materials to achieve effective filtration of water. The inclusion of sand, crushed anthracite coal, garnet, and ilmenite in the correct answer reflects a combination of properties ideal for trapping particles and providing efficient filtration.

Sand is widely recognized for its ability to provide a stable filtration medium that can effectively remove larger particles from water. Crushed anthracite coal enhances the filter’s capacity to capture smaller particulates due to its angular shape and higher surface area. Garnet, a natural mineral, is denser than sand and can aid in the removal of both fine suspended solids and turbidity. Ilmenite, which is another mineral, can be used for its unique properties and further improves performance in certain filtration scenarios.

This combination of materials allows for a multi-layered filtration approach, where each component plays a role in eliminating contaminants from water, resulting in higher efficiency and effectiveness at different particle sizes. Each medium can also contribute to the overall durability and longevity of the filter, making this selection ideal for use in potable water treatment systems.