Which of these does high rate filters not remove?

What is the porosity range during expansion of the filter bed?

What is the surface area of the River rock (Large) packing material used in trickling filters as the packing medium?

For rock type high filtration rate trickling filters what would be the organic loading rate assumed?

Which of these require a flash mixer prior to it?

For rock type of packing in intermediate filtration trickling filters what is the hydraulic rate considered?

For plastic type high filtration rate trickling filters what would be the BOD removal rate?

For roughing type trickling filters what would be the BOD removal rate?