17
Operation manual
ACO Clara
6.4.14 Replacement of aeration elements
The working life of the aeration elements is 5-8 years.
Do not use other types of elements than those approved by
the manufacturer.
The aeration elements are placed on a distribution main which is fixed to
the bottom of the activation tank.
To replace the aeration elements it is necessary to pump out the whole
activation tank and final sedimentation tank volume. It is also recommen-
ded to clean away any remaining sediments.
Before pumping out the volume of the activation tank it is
recommended first to drain the mechanical pretreatment
tank and to use it for the storage of activated sludge.
Leave the activated sludge without aeration for a maxi-
mum of 24 hours.
When the replacement of damaged aeration elements is
carried out it is recommended to do a replacement of all
elements in activation tank and air supply hoses as well.
Replacement procedure:
• Turn off the blower
• Pump out the water from activation tank and final sedimentation tank in
a way to leave app. 150 mm water above the elements (app. 350 mm
from the bottom of the tank)
• Turn on the blower
• Visually check all aeration elements
• Turn off the blower
• Discharge the rest of water
• Unscrew the element(s) in an anticlockwise manner
• Check the cleanliness of the connection
• Provide the connection thread with sealing (e.g. teflon tape)
• Screw in the new element in a clockwise manner
• Fill the activation tank and the final sedimentation tank with water in a
way to have app. 150 mm water above the elements (app. 350 mm
from the bottom of the tank)
• Switch on the blower
• Visually check all aeration elements
• Fill the activation tank and the final sedimentation tank with water (acti-
vated sludge) up to maximum level.
• Visually check the aeration described in Chapter 6.4.2
Sampling and its consequent analysis in an accredited laboratory are the
only conclusive way to evaluate the efficiency of the plant.
When sampling follow the procedures defined by the individual regulati-
ons which are prescribed for the given type of analysis (size of sample,
method, maximum period of storage, etc.).
Using contaminated sampling bottles or tools
(scoop, etc.) for sampling can influence the results
of the analysis. Therefore, before sampling wash
the sampling bottles and all other tools coming
into contact with the sample thoroughly.
If not specified otherwise, keep the obtained sample in a cool and dark
place for a maximum period of 24 hours.
6.5.1 Sample at inlet
It is recommended to sample directly under the inlet pipe or shaft on the
inlet sewer system.
6.5.2 Sample at outlet
Take sample directly from the outlet of the plant in the final sedimentati-
on tank using a scoop or directly to a sampling bottle.
6.5.3 Sample of activated sludge
Take always sample from the activation tank, provided that the blower is
running for a minimum of 1 minute.
6.5
Sampling
Summary of Contents for ClarA 19-38
Page 1: ...Waste water treatment plant ACO ClarA 19 38 24 48 30 60 38 76 48 96 60 100 Operation manual ...
Page 28: ...28 Operation manual ACO Clara F2 F1 OFF O 0 OFF A C D B ...
Page 32: ...32 Operation manual ACO Clara p VACUUM p PRESSURE OFF O 0 OFF A C 1 C 2 B ...
Page 33: ...33 Operation manual ACO Clara No D H XXXXX F D 1 D 2 E ...
Page 36: ...36 Operation manual ACO Clara PRESSURE p p VACUUM OFF O 0 OFF A C 1 C 2 B ...
