An innovative technology based on aerobic granular biomass for treating municipal and/or industrial wastewater with low environmental impact

The paper reports the results of an investigation carried out at lab scale to assess the effectiveness of an innovative technology (SUPERBIO) for treating municipal and/or industrial wastewater. When this technology was applied for treating municipal wastewater, the results showed that even at maximum organic load (i.e. 7 kg COD m⁻³ d⁻¹), the COD in the treated effluent was lower than 50 mg L⁻¹. In addition, both ammonia and TKN removal efficiencies resulted in higher than 87% up to an organic load of 5.7 kg COD m⁻³ d⁻¹ corresponding to a nitrogen load of 0.8 kg TKN m⁻³ d⁻¹.

Very satisfactory process performances also resulted during tannery wastewater treatment, when a chemical oxidation step (i.e. ozonation) was inserted in the treatment cycle of SUPERBIO. In such an instance, at organic and nitrogen loadings of 3 kgCOD m⁻³ d⁻¹and 0.20 kg N m⁻³ d⁻¹, COD, NH⁺₄‐N and TSS average removals were 96, 99 and 98%, respectively. Finally, during the whole experimentation, SUPERBIO was always characterised by a very low sludge production. Such a result was ascribed mainly to the characteristics of biomass that grew in the form of very dense granules (i.e. 130 gVSS L_Biomass⁻¹) allowing a biomass concentration as high as 50–60 gTSS l_bed⁻¹ to be achieved.