Pilot Testing of Primary Effluent Filtration for Carbon Diversion Using Compressible Medium Filter and Disk Filter

Primary effluent filtration (PEF) for carbon diversion is an emerging technology which has not yet been implemented at wastewater treatment plants (WWTP), although the potential energy and capital cost savings are significant. A PEF pilot project was conducted at the City of Roseville’s Dry Creek WWTP in 2011. The pilot study was conducted to evaluate the feasibility of PEF for carbon diversion to reduce aeration power requirements, increase treatment plant capacity, and increase the recovery of energy through increased digester gas energy production. The primary objective of the pilot study was to assess the hydraulic and removal performances of PEF using two different wastewater filters (Compressible Media Filter and SuperDisc Filter). Hydraulic and removal performance results observed during this pilot project are encouraging towards implementation of PEF for carbon diversion at WWTPs. Successful backwashing of the filters combined with the observed removal rates are important indications of the feasibility of primary effluent filtration to reduce aeration power requirements and to increase digester gas energy production.