Office of Technology Transfer – University of Michigan

Multistage Bioreactor with Fixed Biofilm Growth for Biological Treatment

Technology #2018-456

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Steven J Skerlos, Ph.D.
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Managed By
Jeremy Nelson
Senior Licensing Specialist, Physical Sciences & Engineering 734-936-2095

The water treatment field is increasingly moving towards anaerobic membrane bioreactors (AnMBRs) for a variety of applications due to their many advantages, including generation of biogas that can be used to offset the system’s energy and heat requirements. Typical AnMBRs, with a single large created connected to an external membrane unit, are already successfully employed at mesophilic (30-50°C) and thermophilic (>50°C) temperatures. Operation at lower temperatures (<30°C) have proven more difficult due to long start-up times, reduced overall COD removal rates, and an increased sensitive to factors such as loading rate.

Efficient Low Temperature Multi-Stage Dynamic Anaerobic Membrane Bioreactor

The proposed technology is a multi-stage dynamic anaerobic membrane bioreactor that can operate at high loading rates and low temperatures. The system uses conductive meshes to both divide the reaction chamber into compartments and to support the active biofilms. An innovative flow program controls biomass migration and substrate staging between the compartments. The biofilm-supporting meshes divide the chamber but also decrease mass transfer limitations and increase the direct electronic interactions between the microbial populations. After treatment in the AnMBR, the effluent is filtered in a conventional membrane unit. This system can be operated at low (psychrophilic) temperatures making it ideal for cold and/or mild climates. The system is designed to minimize dissolved methane in the permeate, thereby increasing the recoverable biogas of the system and reducing net greenhouse gas emissions.


·  Industrial wastewater treatment

·  Municipal wastewater treatment

·  Treatment of brewery wastewater


·  Stable operation even at low temperatures (i.e., psychrophilic conditions, <30°C)

·  High loading rates, even at low temperature

·  Membrane-bound biofilm decreases mass transfer limitations

·  Conductive mesh decreases chemical energy losses

·  Increased methane (energy) collection efficiency