A rotating membrane contactor: Application to biologically active systems

Gas transfer through hollow fiber membranes allows for rapid transfer kinet ics, high transfer efficiencies, and the ability to precisely control trans fer rates. Despite these advantages, membrane gas transfer has not been use d extensively in industrial fermentation or wastewater treatment. Module pl ugging and biofouling are problematic with current contactor designs, makin g: membrane gas transfer unattractive for applications where the growth of microorganisms is encouraged. Recently, a novel rotating contactor configur ation was designed to give high transfer rates and simultaneously alleviate these problems. In the rotating contactor configuration, the hollow fiber membranes are pulled through the water, reducing energy requirements. Solid s are also able to pass through the fluidized fibers without being filtered . In addition, the entire fiber length experiences a similar flow velocity. This makes the control of biological fouling possible. Pilot plant experim ents on a rotating membrane contactor operated in wastewater are presented. The performance of the rotating contactor design in such an environment wh ere the potential for biological fouling exists is evaluated as a function of operating parameters and time in service. Membrane failures are addresse d and the transfer performance is compared to other contactor configuration s and aeration systems.