Impact of linear alkylbenzene sulfonate (LAS) on the performance of an aerobic granular sludge (AGS) reactor

Linear alkylbenzene sulfonate (LAS) is an anionic surfactant found in detergents that can cause toxic effects when released into the environment. The removal of this pollutant through aerobic treatment technologies faces challenges related to biomass stability. Therefore, there is a need to explore technologies capable of removing it while maintaining long-term stability, such as aerobic granular sludge (AGS). In this study, the stability of granular biomass was investigated in a sequencing batch reactor with an influent containing 10 mg L -1 LAS. Degranulation occurred at the beginning of LAS addition, but biomass stability was recovered after acclimatization. Pollutant removal was minimally affected, with ammonia removal remaining around 85%, improved phosphorus removal (from approximately 14% to 20%), and LAS removal reaching 99% efficiency. LAS exposure stimulated EPS and other resource production, while the microbiota showed reduced abundance in most functional microbial groups.