title: Improving the nitrogen removal efficiency of an A2/O based WWTP by using an on-line knowledge based expert system.
abstract: The results obtained using an expert system to control an activated sludge process involving nutrient removal are reported. The study was conducted at a pilot plant using an Anaerobic/Anoxic/Oxic (A2/O) scheme for which a distributed control system was specially developed. The system allows various expert operational approaches to be developed with a view to minimize nitrogen levels in the outlet while using the minimum amount of energy. The proposed distributed control system is supervised by a Knowledge Based Expert System (KBES) constructed with G2 (a tool for expert system development) and permits the on-line implementation of every operating strategy of the experimental system. A set of experiments involving variable loads and flow-rates was carried out. It revealed that the amount of removed nitrogen could be increased by 11% compared to the usual operating conditions. This increase resulted in a decrease in the amount of total nitrogen and ammonium nitrogen in the outlet by 49% and 64%, respectively. These improvements were achieved with little energy cost because the performance of the treatment plant was optimised using operating rules implemented in real time.
authors.affiliation: Department d'Enginyeria Química, ETSE, Universitat Autònoma de Barcelona, Bellaterra, Spain. juanantonio.baeza@uab.es
authors.forename: J A
authors.initials: JA
authors.lastname: Baeza
authors.forename: D
authors.initials: D
authors.lastname: Gabriel
authors.forename: J
authors.initials: J
authors.lastname: Lafuente
mesh_terms: D001185:Artificial Intelligence; D001421:Bacteria, Anaerobic / Q000502:physiology; D019149:Bioreactors; D004867:Equipment Design; D009584:Nitrogen / Q000378:metabolism*; D010865:Pilot Projects; D012722:Sewage / Q000382:microbiology*; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D012722:Sewage; D009584:Nitrogen