Activated Sludge
Aerobic floc in a healthy state are referred to as activated sludge. While aerobic floc has a metabolic rate approximately ten times higher than anaerobic sludge, it can be increased even further by exposing the bacteria to an abundance of oxygen.
Compared to a septic tank, which takes several days to reduce the organic material, an activated sludge tank can reduce the same amount of organic material in approximately 4-6 hours. This allows a much higher degree of overall process efficiency.
In most cases treatment efficiencies and removal levels are so much improved that additional downstream treatment components are dramatically reduced or totally eliminated.