Question

1. A flocculation basin must be drained with a drain line of how big in diameter?

2. Can you alone buy and install a solids contact unit for water treatment use for your town?

3. Where should a head loss sensor be located for a sand filter?

4. What is the freeboard requirement for a slow sand filter?

5. What exact specifications would you need to tell your supplier for your sand for a rapid sand filter?

6. IF you are going to handle your residuals with drying beds, what is the minimum size of a bed allowed?

Answer 1

Ans 1) A flocculation basin must be drained with a drain line of at least 4 inches in diameter .  

Ans 2) No, someone alone cannot install solid contact unit for the town because it is a large chamber which combine the function chemical treatment , mixing flocculation and sedimentation which is out of scope of one individual

Ans 3) Head loss sensor should be placed at top and bottom of filter column of sand filter

Ans 4) Free board requirement for slow sand filter is 0.2 m

Ans 5) Specification of sand required for rapid sand filter are as follows :

Size = 0.4 5mm - 0.55 mm (for single media)

= 0.9 - 1.1 mm (for dual media )

Desnity = 2.65 gm/cc

Porosity = 0.42 - 0.47

Spherecity = 0.70 - 0.80

Ans 6) Minimum size of bed allowed for drying bed is 4 m width and 15 m long