Backwash Water Source

A clear backwash water storage tank should be provided for at least a 7-min-backwash period at 15 gpm per sq ft or more. For a battery of three or more filters, the clear backwash water supply can be the filtered effluent from other filters.

Filter runs are terminated when (1) the head pressure loss across the filter reaches a predetermined value (10 ft H2O), (2) the effluent turbidity exceeds the acceptable

FIG. 7.33.1 Multilayered filter showing a flat underdrain deck with long-stem nozzles for washing with backwash and air.
0 0

Post a comment