The Aqua-EMBR system consists of an activated sludge, extended aeration, biological treatment process and an ultrafiltration membrane system for the separation of activated sludge from treated effluent. Aqua-EMBR is an external membrane bioreactor system; the ultrafiltration membrane is positioned outside the bioreactor tank, rather than submerged in the bioreactor tank or in the downstream membrane tank.
The ultrafiltration membrane modules are arranged vertically and aerated continuously at the bottom. Mixed liquor is transported via “air lift pump” action through the module, while the membrane feed/recirculation pump is only used to overcome the hydraulic losses and maintain a relatively constant flow of mixed liquor through the membrane. This design reduces much of the feed pumping energy requirement needed to maintain high crossflow velocity, Aquatech says.
Permeate flow, which is inside-out from the membrane modules, is collected by a permeate pump.
Because no membrane components are submerged in the biological mixed liquor, the biological and membrane systems can be operated and optimized independently. The membrane operation is automatically controlled.
With its tight membrane pore size, Aqua-EMBR produces high effluent quality – an important factor for reuse purposes and future regulations, Aquatech says.
Applications for Aqua-EMBR include wastewater treatment or reclamation in new industrial and municipal wastewater treatment plants or in existing plants undergoing upgrades.
Aqua-EMBR offers several benefits over submerged MBR systems, which already present advantages over conventional activated sludge systems, Aquatech says. Because the Aqua-EMBR system has no membrane tank, it can be built more quickly. Installed as one or more skids on a flat concrete slab, the system eliminates the need for complex civil engineering and lowers the risk for contractors due to construction delays caused by weather conditions, environmental or other local uncertainties.