Performance of low flux sponge membrane bioreactor treating industrial wastewater for reuse purposes

A lab-scale membrane bioreactor (MBR) was operated without and with polyethylene sponge addition (20 % v/v) at low fluxes of 2, 3, and 4 LMH to evaluate the performance of treating industrial wastewater for reuse purposes. Biomass grown in sponge-MBR was better than that in conventional MBR, and biomass inside sponges made up 60 % to 83 % of the total biomass in sponge-MBR. The denitrification efficiency of sponge-MBR (24-45 %) was significantly higher than that of the MBR (4.3-7.0 %), resulting in the same trend of TN removal. Total membrane resistances of the sponge-MBR were reduced by 43 % and 48 % at fluxes of 2 and 4 LMH, respectively. Adding sponges to MBR could reduce membrane fouling in terms of cake resistance reduction by 83 % and 73 % at low fluxes of 2 and 4 LMH, respectively. Sponge-MBR can be used as a promising approach for wastewater reuse purposes in an industrial zone.