Anaerobic membrane bioreactor (AnMBR) scale-up from laboratory to pilot-scale for microalgae and primary sludge...

This research work proposes the scale-up evaluation in terms of biological and filtration performance from laboratory to pilot-scale of an anaerobic membrane bioreactor (AnMBR) co-digesting raw microalgae and primary sludge. Best operating conditions for this scale-up were energetically and economically assessed based on laboratory results. Economic balance showed 3% higher annual costs when operating a reactor at 100 d solids retention time (SRT) compared to 70 d SRT. Energetic balance showed a 5.5-fold increase in heat demand working at thermophilic temperature comparing to mesophilic. The AnMBR operating conditions were set at 70 d SRT and 35 °C. The pilot-scale and lab-scale co-digesters performed similarly in terms of biogas production and system stability. 154 mLbiogas·d^-1·L^-1_reactor were produced at pilot-scale, corresponding to methane yield of 215 mLCH₄·gCOD_inf^-1. AnMBR filtration at both laboratory and pilot-scale showed stability working at permeate fluxes of 4.2-5.8 L·m^-2·h^-1.