Where is the rock in most trickling filters placed?

In trickling filter systems, the rock serves a crucial role in supporting the filtration media and facilitating optimal water flow. Placing the rock on a system of tile underdrains allows for efficient drainage of treated effluent while ensuring that the filtering media is adequately aerated. This configuration helps maintain the appropriate moisture levels needed for microbial biofilm growth on the rock and enhances the overall treatment process.

The tiles beneath the rock enable the collected wastewater to flow through the media, thus preventing waterlogging and ensuring consistent movement of treated water. This setup is essential for maintaining the effectiveness of the trickling filter in breaking down organic material present in the wastewater.