In a trickling filter, which order of media occupies the lower portion from top to bottom?

In a trickling filter, the arrangement of media serves specific purposes for effective wastewater treatment. The correct order that occupies the lower portion of the trickling filter from top to bottom is coal, sand, and garnet.

Coal, which is typically used at the bottom, provides a larger surface area for microbial growth and aids in the adsorption of organic compounds, facilitating the breakdown of pollutants. This layer can also help in reducing odors and enhancing treatment efficiency.

Sand is positioned above the coal and contributes to the filtration process by capturing finer particles. It acts as a support layer providing additional structural stability as well as a habitat for beneficial microorganisms necessary for treating wastewater.

Garnet, being the top layer in the setup, typically helps in the initial filtration process and can be used to protect the layers beneath it from clogging. Its characteristics can aid in various forms of treatment, including providing structure and promoting aeration.

This arrangement is strategic for maximizing the exposure of wastewater to microbial action and ensuring that solids are effectively filtered out before the treated effluent exits the system. Each material’s unique properties play a crucial role in the overall function of the trickling filter, making this order of media essential for optimal treatment efficiency.