NUMERICAL MODELING OF FLOW AND AIR DISPERSION INTO AEROBIC GRANULAR SLUDGE BIOREACTOR FOR WASTEWATER TREATMENT.

Innovative aerobic granular sludge (AGS) technology has proved its ability to remove organic pollutants and nutrients from wastewater treatment at the same efficiency, but at a lower costs than conventional biological process. This technology has been successfully applied in sequencing batch reactor (SBR) configuration. An experimental model bioreactor was designed for adapting the AGS technology to continuous flow conditions. This paper presents numerical results for hydrodynamics and air dispersion into bioreactor that highlight dead-zones formation in the corners of the tank, as experiments previously shown. Bioreactor geometry and aeration system has to be optimize to avoid them and to improve mixing, assuring that the entire contents of the aeration tank are kept in suspension. Also, attention should be given to the effects of hydrodynamic factors on the quality of granular sludge. An improved geometry of the tank is proposed, suitable for AGS development and adapted to the aeration system. [ABSTRACT FROM AUTHOR]