Integration of aerobic granular sludge and membrane filtration for tapioca processing wastewater treatment: fouling mechanism and granular stability

Abstract

In this study, a novel aerobic granular sludge membrane bioreactor (AGMBR) was developed and its performance was compared with that of a traditional membrane bioreactor (MBR). The findings of membrane filtration at the flux of 12 L/m 2 h showed that the fouling rate of the AGMBR was 0.490 kPa/day, half that of the MBR. Resistance analysis implied that the cake resistance was the major fouling factor in the MBR, up to 67.2% of total resistance, while pore blocking was the key fouling factor in the AGMBR, accounting for 50.3%. Aerobic granules maintained stability in the AGMBR with a size of 1.2-1.5 mm and a sludge volume index (SVI) of 60-70 mg/L. It was therefore possible to reduce cake resistance and fouling rate. In addition, the concentration of soluble extracellular polymeric substances (sEPS) in the AGMBR was 33.1 mg/L, three times lower than that of the MBR, which resulted in a reduction in membrane fouling for the AGMBR compared with the MBR.

Pathways to Water Sector Decarbonization, Carbon Capture and Utilization

“…Therefore, the batch mode using SBR followed by membrane filtration has been verified as an effective configuration of AGMBR to mitigate membrane fouling and maintain long-term stability of granules. The transmembrane pressure (TMP) increasing rates were mostly lower than 0.3 kPa/d, which were 50-90% lower compared to those of the control MBRs Thanh et al, 2013;Truong et al, 2018). Besides, the AGMBRs also showed good total nitrogen (TN) removal efficiency with higher than 55%, which was attributed to the simultaneous nitrification and denitrification (SND) due to the various microenvironments inside the granules Thanh et al, 2013;Vijayalayan et al, 2014).…”