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

Biofouling impedes the performance of anaerobic membrane bioreactors (AnMBR). Two reactors, one as an upflow attachment-growth AnMBR (UA-AnMBR) configuration, and the other, as a continuously stirred AnMBR (CS-AnMBR) were evaluated for differences in membrane fouling rate. TMP increment in UA-AnMBR was slower than CS-AnMBR, although both reactors had similar COD removal efficiency (ca. > 96%). Slower fouling rate for UA-AnMBR was related to lower total and viable cells, and thereby microbial activity compared to that in CSAnMBR. Acinetobacter and Methanobacterium that played keystone roles in anaerobic biofilm formation were not consistently prevalent on the membranes connected to UA-AnMBR. This is in contrast to both Acinetobacter and Methanobacterium consistently prevalent on the membranes connected to CS-AnMBR. The findings suggest that UA-AnMBR can alleviate membrane biofouling through changes in microbial activity and profile dynamics, and would be a suitable reactor configuration to adopt to achieve an efficient AnMBR for municipal wastewater treatment.

Automated summary

The study showed that the upflow attachment-growth AnMBR (UA-AnMBR) had a slower membrane fouling rate compared to the continuously stirred AnMBR (CS-AnMBR), which was attributed to changes in microbial activity and profile dynamics.