Activated Sludge Process (ASP)

Activated sludge refers to a mass of microorganisms cultivated in the treatment process to break down organic matter into carbon dioxide, water and other inorganic compounds. The activated sludge process has three basic components: 1) a reactor in which the microorganisms are kept in suspension, aerated and in contact with the waste they are treating; 2) liquid-solid separation; and 3) a sludge recycling system for returning activated sludge back to the process. There are many variants of activated sludge processes, including variations in aeration method and in the way the sludge is returned to the process

This technology is very effective for BOD, COD and nutrients removal and provides cost-effective treatment with minimal maintenance however it requires large area and power supply.