Journal of Membrane Science, Vol.547, 34-42, 2018
Coupling microfiltration membrane with biocathode microbial desalination cell enhances advanced purification and long-term stability for treatment of domestic wastewater
In this study, a hollow fiber microfiltration membrane (HFM) coupled biocathode microbial desalination cell (MDC) was fabricated. With real wastewater flowing serially from anaerobic anode to oxic biocathode, filtered by the HFM and finally to the central membrane stack, the HFM-MDC took advantages of conventional anaerobic/ oxic process, membrane biofilm reactor, and eletrodeionization technology, realizing advanced removal of organics, suspended solids, and salinity during 105 days of operation. The produced diluate was 86.1 v%, with final conductivity, chemical oxygen demand, total nitrogen, and total phosphorus (TP) reaching 59.2 +/- 12.2 mu S/cm, 35.5 +/- 4.0 mg/L, 1.65 +/- 0.39 mg/L, and 0.14 +/- 0.05 mg/L respectively. The corresponding concentrate (13.9 v%) concentrated 6.7 times the initial conductivity (6044 +/- 168 +/- mu S/cm), recovered 98.7% of phosphorous (TP of 40.9 +/- 4.9 mg/L) and part of nitrogen. In addition, the HFM was stably operated for 105 days due to coefficient aeration flushing and regular chemical backwashing, with trans-membrane pressure keeping at = 15 kPa for most of time. Moreover, this integrated process only needs wastewater as sole water input, and possesses a relative cheap HFM coupled biocathode compared with conventional Pt cathode, providing a promising solution for practical application of MDC in wastewater purification.