Environmental Engineering Reference
In-Depth Information
Causal factors
•
organic loading due to poor filter effluent quality (recir-
culation), poor primary treatment operation, poor control of sludge
treatment process that results in high BOD
5
recycle flows.
Poor ventilation because of submerged or obstructed underdrains,
Excessive
•
clogged vent pipes, or clogged void spaces
•
Overloaded filter (
hydraulically or organically)
•
Poor housekeeping
Corrective actions
•
Evaluate the operation of the primary treatment process. Eliminate
any short-circuiting. Determine any other actions that can be taken
to improve the performance of the primary process.
•
Evaluate and adjust control of the sludge treatment processes to
reduce the BOD
5
or recycle flows.
Increase the
•
recirculation rate to add additional dissolved oxygen
(DO) to the filter influent. Do not increase the recirculation rate if
the flow rate through the underdrains would cause less than 50%
open space.
•
Maintain aerobic conditions in the filter influent.•
•
Remove debris from media surfaces.
•
Flush underdrains and vent pipes.
•
Add a commercially available masking agent to reduce odors and
prevent complaints.
•
Add
chlorine at a 1- to 2-mg/L residual for several hours at low low
to reduce activity and cut down on the oxygen demand. Chlorination
only treats symptoms; a permanent solution must be determined
and instituted.
7.3.7.3 High Clarifier Effluent Suspended Solids or BOD
Symptoms
•
The
effluent from the trickling filter process settling unit contains
a high concentration of suspended solids.
Causal factors
•
Recirculated flows are too high, causing hydraulic overloading of
the settling tank. In multiple unit operations, the flow is not evenly
distributed.
•
Settling tank baffles or skirts have corroded or broken.
•
The sludge collection mechanism is broken or malfunctioning.
