ABSTRACT
Aerobic digestion is the separate aeration of primary sludge, waste biological sludge, or a blend of these two in an open or closed tank.
A separate sedimentation tank may be used following aerobic digestion, or a one tank, batch type system where the sludge is aerated, mixed, settled, and decanted in the same tank may be used.
The aerobic digestion process is an extension of the extended aeration process. The volatile material in the wastes is digested to a reasonable maximum with up to a 45 percent destruction of volatile solids.
The decomposition of solids and regrowth of organisms is maintained until the available energy in active cells and the storage of waste materials are sufficiently low and stable enough for disposal.
Aerobic digestion reduces the volume of sludge solids and reduces odors or other nuisances that may be a hindrance to final disposal.
