Rapid filtration in the water treatment process typically uses:

Rapid filtration in the water treatment process is characterized by the use of granular media that allows for the quick passage of water through the filter bed while effectively removing contaminants. The correct answer focuses on the use of granular media with greater depths.

When employing granular media of greater depths, the filtration system is able to achieve a larger volume of water processed in a shorter amount of time. This depth increases the contact time between the water and the media, which enhances the removal of particulates and impurities. The increased depth also means that the filter has a larger storage capacity for collected solids, which allows for longer intervals between backwashing cycles, maintaining efficiency in water treatment operations.

Using granular media with greater depths is a significant factor in rapid filtration systems, as it optimizes flow rates and treatment efficiency, which are critical in meeting high water demand and ensuring safe drinking water. The other options do not align with the principles of rapid filtration as effectively, as they either refer to systems designed for slower processing or use inappropriate grain sizes for this method.