A novel eductor-based MBR for the treatment of domestic wastewater

Abstract

A novel aeration device has been developed that combines the mechanism of a venturi aerator with the flow multiplier effect of an eductor used for pump driven mixing. The performance of this novel eductor was evaluated in a flat-sheet immersed MBR and compared with the same MBR equipped with a conventional diffuser for the treatment of domestic wastewater. The eductor showed a higher rate of oxygen transfer both in clean and wastewater compared to the diffuser. The α value with the eductor (0.91) was also found to be more than that of the diffuser (0.75). Higher recirculation rate through the eductor resulted in a higher mixing/turbulance inside the MBR tank and thus alleviated membrane fouling significantly compared to the diffuser. The performance of the MBR in terms of organics removal was also found to be higher with the eductor than the diffuser. The eductor could have significant potential as a combined aerator and mixer in the field of wastewater treatment by MBR.

Keywords: Aeration; Diffuser; Eductor; MBR.