At the recent WEFTEC expo in New Orleans, Fluence featured the SUBRE submerged membrane aerated bioreactor (MABR) technology as an efficient and cost-effective upgrade for existing wastewater treatment plants with conventional activated sludge processes.

The system is designed to achieve high removal of total nitrogen and total phosphorus even in basins not designed for that purpose, and without reducing the basins’ treatment capacity. The Fluence MABR is built for low-energy treatment of municipal wastewater.

It uses a spiral-wound, self-respiring membrane sleeve to provide aeration by diffusion. The membrane module at the heart of the system performs simultaneous BOD, nitrogen and phosphorus removal in a single pass.

The SUBRE solution is designed for basins with capacities from 0.5 to 25 mgd. It occupies about 30 percent of the basin area. A partition is set up between the anoxic MABR zone and the aerobic zone. Mixed liquor nitrate circulation is ceased.

The retrofit is performed using existing basins and aeration equipment with minimal interference with plant operations. Results are achieved in two to four weeks after installation. They system performs nitrification/denitrification to meet effluent requirement. The enhanced bio-phosphorus removal process takes out 80 to 90 percent pf phosphorus compounds. Energy consumption is reduced by 20 to 30 percent, according to the manufacturer.