PERFORMANCE EVALUATION OF A CLOTH MEDIA DISK FILTER FOR WASTEWATER RECLAMATION

A cloth-media disk filter (CMDF) was evaluated as an alternative to granular medium filtration for use in wastewater recycling applications. The CMDF was found to be effective for the filtration of effluent from an activated sludge treatment process and performed equivalent to, or better than, filtration technologies approved for California's Title 22 recycling applications. Effluent turbidity values from the CMDF were consistently less than the Title 22 limit of 2 NTU for influent turbidity values of up to 25 NTU at hydraulic loading rates varying between 7 and 15 m/hr (2.86 and 6.1 gal/ft2•min). The filter produced 154 m3/day (3,781 gal/day) at a hydraulic loading rate of 7 m/hr (2.86 gal/ft2•min) with high turbidity (6–25 NTU), and 330 m3/day (8,102 gal/day) at a hydraulic loading rate of 15 m/hr (6.1 gal/ft2•min) with low influent turbidity (equal to or less than 6 NTU), per m2 (ft2) of filter cloth. The backwash water required by the CMDF at hydraulic loading rates between 7 and 15 m/hr (2.86 and 6.1 gal/ft2•min), and corresponding solids loading rates between 5 and 32 kg/m•day (0.21 and 1.35 lb/ft2•day), varied from 2.0 to 10 percent of the total influent flow. It was concluded that the CMDF could consistently meet the Title 22 requirements of a turbidity less than 2 NTU over a broad range of influent turbidity values and hydraulic loading rates