Solids like fats, grease and oil that float on top of liquid wastewater is called ________ .

scum

The correct answer is Option (2)- scum

The solids like fats, grease, and oil that float on top of liquid wastewater are not called urea, compost, or peat. These terms refer to other substances:

• Urea is a nitrogenous waste product excreted by animals.

• Compost is decomposed organic matter used as a fertilizer.
• Peat is a partially decomposed organic matter found in bogs and wetlands.

• Scum refers to the layer of floating materials, including fats, oils, grease, and other debris, that accumulates on the surface of wastewater. When wastewater containing these substances cools, the fats solidify and form a layer on top. This scum can accumulate in sewage systems, causing blockages and other issues. Therefore, it's essential to remove scum from wastewater treatment systems to prevent clogs and maintain proper functioning.