Applicability of upflow anaerobic sludge blanket and dynamic membrane-coupled process for the treatment of municipal wastewater.

This study investigated the applicability of dynamic membrane filter (DMF) technology in an upflow anaerobic sludge blanket (UASB) and DMF-coupled process for the treatment of municipal wastewater. The overall treatment performance and effects of hydraulic retention time (HRT), operating flux, and mesh pore size on the UASB + DMF were assessed. The UASB + DMF-coupled process demonstrated removal efficiencies of over 64 and 86% for TCOD and TSS, respectively. The effects of filtration flux and support mesh pore size were investigated and it was found that while there was little impact on the treatment performance, a 67% increase in operating flux resulted in a 25% increase in fouling rate. Similarly, with smaller mesh pore size (Mesh 500 with pore size of 28 μm) the fouling rate increased by fourfold as compared to Mesh 300 (pore size of 46 μm). In consideration of the operation duration and contaminant removal, the DMF with Mesh 300 support layer and operating at 100 L/m-h was the most efficient configuration for treating the effluent of the UASB operated with a HRT of 6 h. Microbial analyses of the foulant layer revealed changes in relative abundance as compared to the bulk sludge, particularly with the hydrogenotrophic methanogens completely outcompeting the acetoclastic methanogens. Overall, the coupled process improved the system robustness and reduced variability of the treated effluent.