Technical Note 6 - Applicability aerobic granular sludge technology in the Brazilian context

Abstract

Aerobic granular sludge (AGS) is currently considered one of the most promising technologies for biological wastewater treatment. This fact is mainly due to the combined removal of organic matter and nutrients in the same reactor, eliminating secondary settlers, making it one of the most compact technology on the market. However, there are several reports of problems, including: (i) instability of the granular biomass; (ii) long start-up periods due to slow granule formation, especially when using sewage with a low concentration of organic matter; (iii) accumulation of nitrite in the final effluent; (iv) high demand for automation; and (v) operational process not yet fully established. Thus, despite considerable advances in sewage treatment with AGS systems and the increase in the number of full-scale sewage treatment plants (STPs) in several countries around the world, an integrated assessment of its application in Brazil is necessary. This technical note aims to present the state-of-the-art of AGS system, as well as to bring up a more in-depth discussion, in the Brazilian context, on the need or not to adopt it, and in what situations it should be implemented to replace other sewage treatment technologies with greater mastery of national engineering and usual lower investment and operating costs.