Question

What is the primary composition of municipal sewage by mass?

Options

• 99.5–99.9% water and 0.1–0.5% organic/inorganic matter and microbes

• 50.0–60.0% water and 40.0–50.0% organic matter

• 90.0–92.0% water and 8.0–10.0% toxic industrial effluents

• 75.0–80.0% water and 20.0–25.0% suspended solids

Answer 1

Typical municipal sewage is overwhelmingly liquid, containing approximately 99.5–99.9% water and only about 0.1–0.5% suspended or dissolved organic/inorganic impurities and pathogenic microorganisms.