AWWA JAW31571

Full-scale and dual- and mixed-media filters were compared side by side at nominal loadings of 3, 4, 5, and 6 gpm/sq ft for eight months using flocculation and sedimentation pretreatment. Both media produced an effluent of < 0.5 ntu at all loadings. The mixed-media filter was more successful than the dual-media filter for attaining a potential 0.1 ntu effluent standard using the plant's current pretreatment. The media performed equally in removing residual aluminum and would require about the same initial filter to waste, roughly 0.5 percent of the run. Neither media showed turbidity breakthrough when subjected to a 33 percent flow surge or showed significant media loss. The mixed media showed slightly higher energy costs, which were not considered significant. For replacing media in the eight remaining filters, the mixed media was estimated to cost $48,000 more for the media itself and installation and to cost between $4,000 and $17,000/year more for backwash water. Includes 13 references, tables, figures.

Product Details

Edition:

Vol. 84 - No. 6

Published:

06/01/1992

Number of Pages:

6

File Size:

1 file , 1.5 MB