Feasibility evaluation of submerged anaerobic membrane bioreactor for municipal secondary wastewater treatment

A laboratory-scale submerged anaerobic membrane bioreactor (SAnMBR) was operated for 106 days for municipal secondary wastewater treatment. COD removal efficiency of approximately 90% with methane yield rate of 0.26 LCH4/gCODremoval was achieved. The results of laboratory-scale experiment served to full-scale SAnMBR design. Cost analysis of the full-scale SAnMBR system showed that membrane costs and gas scouring energy accounted for the largest fraction of total life cycle capital costs and operational costs, respectively. The operational costs can be totally offset by the benefits from biogas recovery. Sensitive analysis showed that membrane parameters including flux, price and lifetime play decisive roles in determining the total life cycle costs of the SAnMBR. The study demonstrated the technical feasibility as well as economic feasibility of SAnMBR treating municipal wastewater, providing that the membrane performance was significantly improved or membrane price significantly decreased.

► A comprehensive cost analysis of full-scale SAnMBR was performed.
► Operational costs of SAnMBR can be totally offset by biogas recovery benefits.
► Membrane parameters played decisive roles in determining the total costs.