ADVANCED OXIDATION DITCH (A20) PROCESS A2O
PROCESSA2O Process (Anaerobic+ Anoxic+ Aerobic)
The Advanced Oxidation Ditch Process or three-stage A2O process consists of a Modified Ludzack-Ettinger (MLE) process for nitrogen removal, with an anaerobic zone in front for phosphorus removal .The process is called A2O since it consists of anaerobic/anoxic/oxic (aerobic) tanks in series. The RAS is recycled to the anaerobic zone. The anaerobic zone is followed by an anoxic zone for nitrogen removal through de-nitrification. IR is recycled from the aerobic zone to the anoxic zone at a rate of 100 to 400 percent of influent. Nitrogen removal is limited by the IR flow and this is achieved by means of IR gates contrary to the heavy duty pumps which consumes high amount of power . This is a relatively simple process to operate. The process has a small footprint.