AEROBIC GRANULAR SLUDGE SYSTEMS: THE NEW GENERATION OF WASTEWATER TREATMENT TECHNOLOGIES

The paper reports the results of a laboratory investigation aimed at evaluating the effectiveness of an innovative technology (SBBGR), based on aerobic granular biomass, for treating diluted (i.e., municipal wastewater) or concentrated wastewater (i.e., municipal landfill leachates). When this technology was applied to the treatment of municipal wastewater, the results showed that even at maximum organic load (i.e., 7 kg COD/m3d), the COD in the treated effluent was lower than 50 mg/L. In addition, TKN removal efficiency resulted higher than 87% up to an organic load of 5.7 kg COD/m3d corresponding to a nitrogen load of 0.8 kg TKN/m3d. Process performances also resulted very satisfactory during the treatment of a mature municipal landfill leachate. In this case, the SBBGR proved suitable for removing the whole content of biodegradable compounds (i.e., about 80% of the COD content of the leachate) up to an applied organic loading value of 1.1 kg COD/m3d. During the whole investigation, the process was characterised by a very low sludge production, about one order of magnitude lower than that of conventional systems.