A feasibility investigation of a pilot-scale bioelectrochemical coupled anaerobic digestion system with centric electrode module for real membrane manufacturing wastewater treatment

The large-scale application of bioelectrochemical coupled anaerobic digestion (BES-AD) is limited by the matching of electrode configuration and the applicability of real wastewater. In this study, a pilot-scale BES-AD system with an effective system volume of 5 m3 and a 1 m3 volume of a carbon fiber brush electrode module was constructed and tested for treatment of the membrane manufacturing wastewater. The results showed that the BOD5/COD of the wastewater was increased from 0.238 to 0.398 when the applied voltage was 0.9 V. The pollutants such as N, N-Dimethylacetamide and glycerol in wastewater were degraded significantly. The microorganisms in the electrode modules were spatially enriched. The fermenters (Norank_f__ML635J-40_aquatic_group, 6.55 %; unclassified_f__Propionibacteriaceae, 5.25 %) and degraders (Corynebacterium, 29.31 %) were mostly enriched at the bottom, while electroactive bacteria (Pseudomonas, 29.39 %, Geobacter, 7.86 %) were mostly enriched at the top. Combined with the economical construction and operation cost ($1708.8/m3 and $0.76/m3) of the BES-AD system.

Automated summary

A pilot-scale bioelectrochemical coupled anaerobic digestion (BES-AD) system was constructed and tested for the treatment of membrane manufacturing wastewater. The results showed increased BOD5/COD ratio and significant degradation of pollutants. Spatial enrichment of microorganisms in the electrode modules was observed, with fermenters and degraders mostly enriched at the bottom and electroactive bacteria mostly enriched at the top. The economical construction and operation cost of the BES-AD system further highlights its importance.