What is the physical process used for initial sewage treatment?

What is the physical process used for initial sewage treatment?

• A. Sewage Runoff
• B. Harmful Algal Blooms
• C. Primary Sewage Treatment
• D. Raw Sewage

Answer: (C)

Initial sewage treatment relies on physical processes to remove solids before any biological treatment. In primary treatment, wastewater is first passed through screens to remove large debris, then directed into a sedimentation tank where gravity pulls suspended solids to the bottom, forming sludge and leaving clearer water at the top. This physical separation significantly reduces the solids load and turbidity that downstream processes must handle. The other terms aren’t treatment steps: raw sewage is the untreated material, harmful algal blooms are ecological phenomena, and sewage runoff describes polluted water flow, not a treatment process.

Initial sewage treatment relies on physical processes to remove solids before any biological treatment. In primary treatment, wastewater is first passed through screens to remove large debris, then directed into a sedimentation tank where gravity pulls suspended solids to the bottom, forming sludge and leaving clearer water at the top. This physical separation significantly reduces the solids load and turbidity that downstream processes must handle. The other terms aren’t treatment steps: raw sewage is the untreated material, harmful algal blooms are ecological phenomena, and sewage runoff describes polluted water flow, not a treatment process.