Prokaryotic communities in a two-stage EGSB system treating pig slurry under increasing upflow velocity
This study investigated the effect of upflow velocity on the performance and microbial community dynamics of a pilot-scale two-stage expanded granular sludge bed (EGSB) system treating real pig slurry. Different hydrodynamic conditions were applied while maintaining constant hydraulic retention times to evaluate their influence on reactor performance, biomass retention, granulation, and microbial community structure. Bacterial and archaeal communities were characterized by 16S rRNA gene amplicon sequencing at different operational stages to assess their temporal response to changes in upflow velocity and their differentiation between the hydrolytic/acidogenic and methanogenic reactors.