RESUMEN
A novel continuous flow system with "flat geometry" composed by two completely mixed aerobic tanks in series and a settler was used to promote the formation of aerobic granular sludge. Making similarities of this system with a typical sequencing batch reactor (SBR), for aerobic granules cultivation, the value of the tank 1/tank 2â¯vol ratio and the biomass recirculation rate would correspond with the feast/famine length ratio and the length of the operational cycle, respectively, while the settler upflow liquid velocity imposed would be related to the settling time. From the three experiments performed the best results were obtained when the tank 1/tank 2â¯vol ratio was of 0.28, the sludge recycling ratio of 0.25 and the settler upflow velocity of 2.5â¯m/h. At these conditions the aggregates had settling velocities between 29 and 113â¯m/h, sludge volume index at 10â¯min (SVI10) of 70â¯mL/g TSS and diameters between 1.0 and 5.0â¯mm.