What is the bulk density of pebbles assumed while designing a Pressure sand filter?

What is the specified minimum time for backwash of rapid filters?

What is the rate of backwash water?

What is the percentage of wash water?

For rock type low filtration rate tricking filters what would be the BOD removal rate?

While designing a blower for backwash for multimedia filters without air scouring what is the velocity considered?

Orifice placement is critical to the successful operation of the clarifier.

Pre-treatment of beds is not necessary.