Membrane bioreactors

A membrane bioreactor (MBR), widely used in industrial and municipal applications, is an effective wastewater treatment system that produces high quality effluent suitable for reuse applications.

The membranes retain the biomass and mixed liquor suspended solids (MLSS) within the bioreactor, thus producing effluent that is free of particles, bacteria and viruses. MBRs remove between 96-99% of COD, compared to 95% in conventional activated sludge processes.

Additionally, MBRs can be operated at higher MLSS concentrations of up to 30 g/L.

MBR

In an effort to minimize their short and long-term environmental impact, industries across the globe are facing increasing challenges and costs in the treatment of their process wastewater. As a result, many of these industries have built their own treatment systems in order to treat and reuse process streams, reducing discharge costs to municipal treatment plants and recovering valuable products from effluent.

Traditional wastewater treatment plants consist of pre-treatment systems to capture large floating particles and coarse suspensions (e.g. wood, textile, plastic and stones), followed by biological aerobic digestion that converts organic waste into carbon dioxide, nitrogen gas and water.

After the biological process, the cleaned water is typically separated by gravitational force in settlers or clarifiers in which part of the biomass is then fed again to the biological process. Excess biomass then flows to the thickener for further dehydration.

The last step consists of granular (sand) filtration and chemical treatment which filters and decontaminates the solution from pathogenic microorganisms.