A BioSep MBR, or Membrane Zone, can best be described as the initial step in a biological process where microbes are used to degrade pollutants that are then filtered by a series of submerged membranes (or membrane elements). The individual membranes are housed in units known as modules, cassettes, or racks and a combined series of these modules. Air is introduced through integral diffusers to continually scour membrane surfaces during filtration, facilitate mixing and in some cases, to contribute oxygen to the biological process.

BioSep MBR

BioSep MBR Membrane bioreactors for wastewater treatment is a combination of conventional biological treatment (e.g., activated sludge) processes with membrane filtration to provide an advanced level of organic and suspended solids removal.  The membranes are used to perform the critical solid-liquid separation function. In an MBR system, the membranes are submerged in an aerated biological reactor. The membranes have porosities ranging from 0.04 microns to 0.4 microns, which is considered between micro and ultrafiltration. This level of filtration allows for high quality effluent to be drawn through the membranes and eliminates the sedimentation and filtration processes typically used for wastewater treatment. Because the need for sedimentation is eliminated, the biological process can operate at a much higher mixed liquor concentration.

The two general types of MBR systems are vacuum (gravity-driven) and pressure-driven systems. Vacuum systems are immersed and normally employ hollow fiber or flat sheet membranes installed in either the bioreactors or a subsequent membrane tank. Pressure driven systems are in-pipe cartridge systems located externally to the bio-reactor.

MBR - How it Works

Primary / Fine Screen

A screen that removes large solid particles above a specific size from the waste stream is required preceding the equalization basin.

Equalization Basin

An EQ basin with aeration diffusers and blower.  The EQ basin and the aeration system are sized according to the project requirements

Pump Skid

A pump skid containing EQ transfer pumps, WAS pumps, and EQ/WAS blowers. EQ transfer pumps conveys wastewater from the EQ basin into the secondary fine screen on the MBR process tank. The blowers will feed aeration equipment in the EQ and sludge holding tanks. WAS pumps pull WAS from the MBR process tank to the sludge holding tank. 10% of the WAS is recycled back to the screens.

Modular MBR

The modular MBR system is configured with one Anoxic (AX) Zone, one Pre-Aeration (PA) Zone, and Membrane (MB) Zones. Each zone is separated by a welded baffle structurally designed such that any zone can be fully drained if needed.

Clean in Place (CIP) Tank / Wash Water System

Clean in place “CIP” system is required for regular membrane maintenance. Automatic CIP eliminates the need for the tank and dose pump but requires a plant water supply and additional chemical feed equipment. Wash water is also required for both primary/fine screens.

Chemical Feed System

Chemical feed systems are included for the addition of alkalinity, carbon, and alum for phosphorus removal.

Sludge Holding Tank

A sludge holding tank is required to hold the sludge created during the process.