How is the length of the surface calculated in case of countercurrent settling?

What is the time period for which the water is stored in fill and draw type of sedimentation tank?

How many types of solids are present in water?

What is the detention time assumed while designing a flocculator?

Iron precipitation occurs at which pH?

While designing a rectangular primary sedimentation tank in what range the length should be assumed?

How many hours does the removing of Settleable particles require in fill and draw type of sedimentation tanks?

What is the detention time assumed while designing a flash mixer?