Activated sludge

The solids formed when microorganisms are used to treat wastewater using the activated sludge treatment process. It includes organisms, accumulated food materials, and waste products from the aerobic decomposition process.

A floc or solid formed by the microorganisms. It includes organisms, accumulated food materials, and waste products from the aerobic decomposition process.


Source: Handbook of water and wastewater treatment plant operations

Wikipedia: https://en.wikipedia.org/wiki/Activated_sludge