In sewage treatment systems, an anaerobic filter (AF) is a form of anaerobic digester. The digestion tank contains a filter medium where anaerobic microbial populations—organisms that live in the absence of oxygen — can establish themselves.
Sewage treatment systems utilize anaerobic filters (AFs), which are types of anaerobic digesters. These digesters contain a filter medium, allowing anaerobic microorganisms to establish themselves and carry out digestion.