Aerobic granular sludge in a sequencing batch bioreactor treating synthetic wastewater contaminated with atrazine

The main objectives of this study were to evaluate the efficiency of atrazine removal using aerobic granular sludge (AGS) in a sequencing batch reactor and to investigate the effects of prolonged exposure to atrazine on AGS. Throughout the biological treatment, morphological changes in the granular sludge were monitored using quantitative image analysis, as well as changes in the microbial community. The toxicity of the treated effluent was assessed using the Vibrio fischeri bioluminescence inhibition test. Given the importance of extracellular polymeric substances in AGS systems, their evolution was also assessed.