Pilot Studies and Full Scale Performance Evaluation of a Membrane Disc Aeration System Treating Coated Paper Mill Wastewater at Repap Wisconsin, 1992 Environmental Conference Proceedings

Successful, economic application of synthetic elastomeric membrane fine pore diffusers is becoming established in wastewater treatment plants. The disc configuration and the recent availability of materials with superior environmental resistance have contributed to this development.

This paper describes the experience at the Repap Wisconsin’s wastewater treatment plant at Kimberly Wisconsin. The mill sought to increase its capacity and efficiency by replacing the existing single-stage jet system with a two-stage EPDM membrane grid aeration system.

Prior to design, pilot tests were performed in parallel on both ceramic and EPDM diffusers to assess environmental and fouling resistance. These tests, which led to the selection of membrane diffusers, are described and reported. After approximately one year of operation, full-scale oxygen transfer tests using offgas analysis were performed on the system and sample diffusers were retrieved and tested to determine the presence and extent of environmental changes, if any.