Question

why is layer of sand and charcoal is used in water filtration? (For project in short)​

Answer 1

Explanation:

First, the gravel layer catches large pieces of debris, such as twigs, leaves, and bugs. Next, the sand layer catches smaller particles, such as dirt and grit, and makes the water look clean. Finally, the charcoal layer gets rid of bacteria and some chemicals..

Hope its help..