What is a key factor that filtration by granular media depends on?

Filtration by granular media is fundamentally influenced by adsorption, which refers to the process where particles adhere to the surface of the granular media. In water treatment, the granular media, which can consist of materials like sand or activated charcoal, captures contaminants by attracting and holding them on their surfaces. This ability to adsorb various substances is crucial for effective filtration, as it enhances the removal of impurities from the water being treated.

While other factors such as temperature, pressure, and viscosity can play roles in the filtration process, they primarily affect aspects like the flow rate or the physical behavior of the water and particles. However, adsorption specifically addresses the mechanism by which contaminants are retained within the filtration media, making it a key factor in the efficacy of granular media filtration. This is vital to ensuring that potable water meets safety standards and is free from harmful substances.