Which step in a conventional treatment train primarily removes settleable solids before filtration?

Which step in a conventional treatment train primarily removes settleable solids before filtration?

• A. Sedimentation
• B. Disinfection
• C. Coagulation
• D. Jar testing

Answer: (A)

Sedimentation uses gravity in large basins to settle out the settleable solids after coagulation and flocculation. By allowing heavy particles to settle before water reaches the filters, it lowers the solids and turbidity entering filtration, helping filters operate more efficiently. Disinfection targets microorganisms and doesn’t remove solids; coagulation helps form larger flocs but doesn’t settle them by itself; jar testing is a bench procedure to determine coagulant dose, not a treatment step. So the step that primarily removes settleable solids before filtration is sedimentation.

Sedimentation uses gravity in large basins to settle out the settleable solids after coagulation and flocculation. By allowing heavy particles to settle before water reaches the filters, it lowers the solids and turbidity entering filtration, helping filters operate more efficiently. Disinfection targets microorganisms and doesn’t remove solids; coagulation helps form larger flocs but doesn’t settle them by itself; jar testing is a bench procedure to determine coagulant dose, not a treatment step. So the step that primarily removes settleable solids before filtration is sedimentation.