Design methodology for submerged anaerobic membrane bioreactors (AnMBR): A case study

The main objective of this study is to propose guidelines for designing submerged anaerobic MBR (AnMBR) technology for municipal wastewater treatment. The design methodology was devised on the basis of simulation and experimental results from an AnMBR plant featuring industrial-scale hollow-fibre membranes. The proposed methodology aims to minimise both capital expenditure and operating expenses, and the key parameters considered were: hydraulic retention time, solids retention time, mixed liquor suspended solids concentration in the membrane tank, 20 °C-standardised critical flux, specific gas demand per square metre of membrane area, and flow of sludge being recycled from the membrane tank to the anaerobic reactor. An AnMBR WWTP operating at 15 and 30 °C with both sulphate-rich (5.7 mg COD mg−1 SO4-S) and low-sulphate (57 mg COD mg−1 SO4-S) municipal wastewater was designed. The minimum cost of the designed plant was €0.097 and €0.070 per m3 when treating sulphate-rich and low-sulphate wastewater, respectively.