Civil Engineering Reference
In-Depth Information
Wash
Water
Treated
Water
Raw Water
Backwash Air
Normal Operation
Wash
Water
Treated
Water
Raw Water
Backwash Air
Backwash Operation
Wash
Water
Treated
Water
Raw Water
Backwash Air
Flushing Operation
Fig. 25-6.
Backwash cycle for typical contact clarifier
quality. Typically, the controls are set up to initiate a flushing cycle every 4 to 8 hours.
Unlike conventional filters, complete cleaning of the adsorption clarifier is not required,
as the majority of solids are removed by the violent agitation provided during the first
minutes of the flush cycle. Also, more efficient performance of the adsorption clarifier
occurs if some residual solids are left on the media.
The mixed-media filter is backwashed in a manner similar to that of a conventional
filter. Although the filter may not necessarily be backwashed each time the adsorption
clarifier is flushed, the equipment is designed to ensure that a backwash cycle is always
preceded by a flushing cycle.
USFilter—Microfloc Trimite and Trident Systems
The Trimite and Trident package water treatment plant designs utilize an upflow filter
of high- density plastic bead media, termed an ''adsorption clarifier,'' followed by a
mixed-media filter for final polishing. The adsorption clarifier replaces the flocculation
and settling processes and results in an extremely compact unit. Figure 25-7isaflow
diagram of the typical Trimite and Trident Water System manufactured by USFilter,
