Post-treatment of upflow anaerobic sludge blanket effluent by combining the membrane filtration process: fouling control by intermittent permeation and air sparging

In this study, the membrane filtration process was proposed as a post-treatment process to treat the upflow anaerobic sludge blanket (UASB) effluent. The flat-sheet membrane modules were submerged into the UASB reactor to retain the suspended solids in the UASB effluent under intermittent permeation and air sparging conditions. The results indicated that intermittent permeation enhanced the sustainability of the submerged membrane and an idle time of 4 min with a 10-min filtration was optimal for reducing membrane fouling under the experimental conditions. Air sparging could also alleviate membrane fouling, and the lowest transmembrane pressure (TMP) change rate (dTMP/dt) was achieved at the moderate aeration rate of 2 L/min. It appears to be effective to alleviate membrane fouling and achieve high effluent production at a flux of 25 L/m2 h and an idle time of 4 min with a 10-min filtration considering the energy consumption.