Pebbles

Pebbles are used in water purification as a physical filtration method, trapping larger particles and debris. They form part of a multi-layered filtration system, typically placed beneath sand and above larger gravel, aiding in the initial removal of impurities before the finer media take over.

Here's a more detailed explanation:

• Physical Filtration: Pebbles create a porous matrix that allows water to flow through while trapping larger particles like sediment, organic matter, and debris.
• Support Layer: They provide a support layer for the finer filter media (like sand) above, preventing them from clogging.
• Layered System: In a typical filtration system, pebbles are part of a layered approach, with coarser gravel at the bottom, followed by pebbles or finer gravel, and then a sand layer.
• Initial Impurity Removal: The pebbles help remove larger impurities, reducing the load on the finer filter media and extending their lifespan.