PERFORMANCE OF PILOT SUBMERGED MEMBRANE BIOREACTOR TREATMENT SYSTEMS IN GIRDWOOD, ALASKA

The Anchorage Water and Wastewater Utility (AWWU) has conducted pilot testing of an Enviroquip submerged membrane bioreactor (SMBR) and a ZENON SMBR at the Girdwood Wastewater Treatment Facility (GWWTF) located in Girdwood, Alaska. The Girdwood wastewater is unique relative to other municipal wastewaters in that it is dilute, weak and typically low-temperature. This paper summarizes the results of both pilot tests. Both systems were capable of achieving a high-quality effluent with biochemical oxygen demand (BOD) at or below 5 mg/L and total suspended solids (TSS) at or below 6 mg/L. The Enviroquip pilot SMBR was capable of sustaining a long-term membrane flux rate of approximately 5 gallons per square foot per day (gfd) and the ZENON pilot SMBR was capable of sustaining long-term flux rates between 6 and 8 gfd.