Wastewater Treatment and Membrane Fouling Control Using an Algae-Activated Sludge Self-Forming Dynamic Membrane Bioreactor (AAS-SFDMBR)

Self-forming dynamic membrane bioreactors (SFDMBRs), which utilize formed biomass layer and large pore-size mesh/ support materials instead of conventional membrane materials, have been studied for wastewater treatment applications. The consortium of algae and activated sludge bacteria has also been recently shown to improve pollutant removal and fouling rate reduction in membrane bioreactors (MBR). This study presents a novel Algae-Activated Sludge SFDMBR (AAS-SFDMBR), with combined activated sludge and Chlorella vulgaris as biomass, for wastewater treatment. Pollutant removal efficiency and membrane fouling alleviation by the AAS-SFDMBR were compared to those of a previously reported Algae-Activated Sludge Membrane Bioreactor (AAS-MBR), which utilized a hollow-fiber ultrafiltration membrane. COD removal by the AAS-SFDMBR was only slightly lower than that obtained in the AAS-MBR. NH4+-N removal efficiency was increased by 10.83% in the AAS-SFDMBR. Concentration of membrane fouling pre-cursors in the AAS-SFDMBR mixed liquor, particularly those of the protein fractions of bound Extracellular Polymeric Substances (EPS) and Soluble Microbial Products (SMP), were significantly reduced in the AAS-SFDMBR. Consequently, the fouling rate in the AAS-SFDMBR was lower by 71.25% than that in the AAS-MBR. This study demonstrated the potential of SFDMBR, with algae-activated sludge biomass, as low-cost alternative to conventional MBRs.