An Innovative Submerged Anaerobic Membrane Bioreactor for Treatment of Potato Solids and Bioenergy Production

A submerged anaerobic membrane bioreactor (sAnMBR) was studied for the treatment of a high organic strength wastewater containing a high level of suspended solids. A 25L reactor was operated, under mesophilic conditions (35°C), for 218 days treating a blend of primary clarifier sludge and centrifuge solids from a potato processing plant. The system achieved volumetric loading rates from 3 to 9 kgCOD/m3/d (0.1 to 0.3 gCOD/gVSS/d). Organic removal was consistently high providing 99% COD and cBOD removal in effluent. Average COD and carbonaceous BOD were less than 300 mg/L and 50 mg/L, respectively during steady operating conditions. Effluent TSS were less than 1 mg/L. Methane production yield, from influent solids, decreased from 444 to 393 mL CH4/gVSS/d as the organic loading rate (OLR) increased. Operating flux diminished from 0.28 to 0.11 m3/m2/d, as the OLR increased. Membrane fouling occurred as a result of sludge cake formation.