Microbial characterization and removal of anionic surfactant in an expanded granular sludge bed reactor

► First evidence of anaerobic removal of linear alkylbenzene sulfonate this reactor. ► We varied the hydraulic retention time and characterized (16SrRNA) the biomass. ► LAS removal (∼64%) was favored with an increase in contact time (biomass-LAS). ► Dilution and mass transfer contributed to the global removal (57%). ► Microbial diversity was different between the biomass (sludge bed and phase separator).