Towards bio-utilization and energy recovery potential exploration of membrane foulant from membrane bioreactor by using microbial fuel cell-centered technology

The utilization of membrane foulant is expected to push forward the developments of membrane bioreactor (MBR). In this study, the combination of microbial fuel cell (MFC) with bio-electrochemical enhanced hydrolysis process was proposed, and three systems were conducted to utilize the membrane foulant and simultaneously harvest electricity. Polysaccharides (PS), proteins (PN) and humic acid (HA) concentration variations and the fluorescent compound changes in different chambers revealed the biodegradability of membrane foulant. Optimized HRT improved the hydrolysis of membrane foulant while allowing MFC to utilize the biodegradable components efficiently. MFC-MFC system had the highest voltage and satisfactory effluent quality at HRT of 1 d. Microbial community structure analysis indicated that Proteobacteria, Planctomycetes and Bacteroidetes were the majority phyla and network analysis further revealed that Proteobacteria played a key role in membrane foulant utilization. This study suggests that MFC hybrid systems has potential application for synchronous membrane foulant reuse and energy recovery.

Automated summary

This study proposed the combination of microbial fuel cell (MFC) with bio-electrochemical enhanced hydrolysis process to simultaneously utilize membrane foulant and generate electricity. The biodegradability of the foulant was revealed through variations in polysaccharides, proteins, humic acid concentrations, and fluorescent compounds in different chambers. Optimized hydraulic retention time improved foulant hydrolysis and enabled efficient utilization of its biodegradable components by MFC. The MFC-MFC system achieved the highest voltage and satisfactory effluent quality at a hydraulic retention time of 1 day. Microbial community structure analysis showed that Proteobacteria, Planctomycetes, and Bacteroidetes were the dominant phyla, with Proteobacteria playing a key role in foulant utilization. This study suggests that MFC hybrid systems have potential for synchronous foulant reuse and energy recovery.