Detritus is best described as which of the following?

• A. Dissolved minerals
• B. Fine organic material
• C. Heavy coarse grit in wastewater
• D. Suspended fungi

Answer: (C)

Detritus in wastewater refers to solid material that settles out of the flow due to gravity, and in many plant contexts it is the heavy, inorganic solids known as grit. These coarse particles, like sand and gravel, are removed early in grit chambers to protect pumps and downstream processes from abrasion and blockage. Dissolved minerals aren’t detritus because they aren’t solids and don’t settle; they remain in solution. Fine organic material can be suspended as dissolved or colloidal matter and isn’t the descriptor most associated with detritus. Suspended fungi describe a biological component rather than the typically inert, heavy solids that detritus represents. So, describing detritus as heavy coarse grit best fits its usual meaning in this context.