Attached-growth configuration outperforms continuously stirred tank anaerobic membrane bioreactors in alleviating membrane biofouling. Attached-growth configuration outperforms continuously stirred tank anaerobic membrane bioreactors in alleviating membrane biofouling

Biofouling impedes the performance of anaerobic membrane bioreactors. In this study, two lab-scale bio-entrapped up-flow attachment-growth anaerobic membrane bioreactor (UA-AnMBR) and continuously stirred AnMBR (CS-AnMBR) were applied to treat municipal wastewater. Lower biomass, soluble microbial products and extracellular polymeric substances concentration were obtained in this bio-entrapped reactor compared to CS-AnMBR. The TMP increment in UA-AnMBR is slower than that in CS-AnMBR. A consequential less in biofilm composition related to total cells, live cells, polysaccharides, protein, and bioactivity (i.e., adenosine triphosphate (ATP)) was observed in UA-AnMBR than CS-AnMBR. High-throughput sequencing data analysis indicated the anaerobic microbial consortium in both sludge and biofilm were largely affected by stochastic dispersal and migration processes (i.e., neutral assembly). However, Acinetobacter spp., Smithella spp., Syntrophorhabdus spp., and Syntrophobacte spp. occurred consistently in higher frequency in the biofilm. Due to the neutral assembly between sludge and biofilm, less biofilm associated microorganism by UA-AnMBR would benefit the fouling control. These findings of this study collectively suggest bio-entrapment based reactor can significantly enhance membrane filtration performance.