Oxidation Ditches
Here the wastewater is aerated which keeps a steady supply of aerobic bacteria which feed on the organic material in the wastewater and help remove nitrogen. As the bacteria grow, they clump together, suspended in the wastewater. These clumps are the activated sludge. Some of this sludge is removed in the final clarifiers and some is returned to the oxidation ditches to keep a good supply of bacteria to aid in the treatment of more incoming wastewater.
