Figure 1: Schematic representation of the experimental setup: (1) crosssectional view of the nitrifying/denitrifying reactor operated in fed-batch mode; (2) mechanical stirrer; (3) turbine impeller; (4) stainless steel basket; (5) peristaltic pump-feeding; (6) diaphragm pump-discharge; (7) porous stone; (8) aquarium air pump; (9) entry for micro-sensors.