A novel aerobic electrochemical membrane bioreactor with CNTs hollow fiber membrane by electrochemical oxidation to improve water quality and mitigate membrane fouling. (15th March 2019)

• Record Type: Journal Article
• Authors: Yang, Yue; Qiao, Sen; Jin, Ruofei; Zhou, Jiti; Quan, Xie
• Is Part Of: Water research. Volume 151(2019)
• Page Start: 54
• Page End: 63
• Publication Date: 2019-03-15
• Subjects: EMBR -- Carbon nanotubes hollow fiber membranes -- Membrane fouling -- Transmembrane pressure -- Electrochemical effect; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2018.12.012
• Languages: English
• ISSNs: 0043-1354

Abstract

Abstract: A novel electro-assisted membrane bioreactor (EMBR) was constructed by integrating conductive carbon nanotubes hollow fiber membranes (CNTs-HFMs) into an aerobic activated sludge system. Herein, the CNTs-HFMs served as anode and filtration core simultaneously. Contrasted with the other two MBRs (PVDF-HFMs and CNTs-HFMs without electro-assistance), the effluent COD and NH4 + N were lower than 40 mg/L and 3 mg/L at +1.0 V even HRT as short as 4 h. However, they were mostly over 50 mg/L (COD) and 5 mg/L (NH4 + N) under the same conditions in the other two MBRs. The hydraulic cleaning for electro-assisted CNTs-HFMs was carried out only once during 60-day operation, and the permeate flux recovered to 100% of the original status. While four and five times hydraulic cleaning were executed for other two MBRs (PVDF-HFMs and CNTs-HFMs), respectively. Furthermore, merely 50 min continuous electrochemical oxidation was enough to resume flux of the heavily fouled CNTs-HFMs, i.e. flux recovered to 2020.87 L/(barm 2 h) from 394.68 L/(barm 2 h) (pure water flux, ∼2200 L/(bar·m 2 ·h)). Simpson and Shannon indexes indicated enhanced microbial community stability in EMBR. Thus, electro-assisted CNTs-HFMs endow EMBR excellent anti-fouling ability and good effluent quality. Graphical abstract: Image 1 Highlights: A novel EMBR system was constructed via combining electrochemical oxidation with CNTs-HFMs as anode. Electro-assisted CNTs-HFMs exhibited excellent anti-fouling abilities in EMBR. COD and NH4 + N were further removed in EMBR by electrochemical oxidation. Flux recovery of fouled CNTs-HFMs reached about 92% under electro-assistance.