What is the bulk density of sand assumed while designing the amount required for a sand filter?

What is the depth of washing during high-rate water backwash?

While designing a blower for backwash for multimedia filters with air scouring what is the velocity considered?

While designing a pump for backwash for a filter what will be the velocity assumed?

Which of these is the most efficient?

What is the shape of a typical trickling filter?

The synthetic fibres used are temperature resistant.

While designing an HRSCC what is the detention time assumed for the detention hood?