30-percent solution of hydrochloric acid. If
clogging is by soot, oil, or dust from
improperly filtered air, remove the diffusers
and burn off the extraneous material in a
Porous ceramic tubes. Tubes may be removed
and cleaned by soaking in acids or by burning
(as described for porous plate diffusers).
Porous Saran-Wound Tube Diffusers
These diffusers should be inspected and cleaned
semiannually as necessary. This material cannot be
subjected to strong acids or heat. It must be scrubbed
with a brush and soap or detergent.
Injection nozzles should be inspected and cleaned
semiannually as necessary. Diffuser nozzles on header
lines may become clogged from deposits inside from
iron oxide particles, or on the outside from organic
growths. Clogging from the inside may require
removal of the individual nozzles for cleaning.
Chlorine gas injection into the air line header between
inspections will hold down organic growths. At
inspection periods, if growths are present, scrub them
off with a brush and detergent solution to which
hypochloride has been added.
SPRAY NOZZLE AERATORS
The maintenance procedures for spray nozzle
aerators is as follows:
At weekly intervals, check the nozzles for
clogging, and clean when necessary. Remove
the nozzles only when necessary. Check for
Quarterly, check air line manifolds, remove caps
and clean out sediment; check for joint leaks.
Check pipe supports, replace or repair, and paint
When spray fences exist, repair and paint them
BLOWERS AND ACCESSORY
The procedures for injection aeration is as follows:
Daily, lubricate the blower or compressor under
the manufacturers instructions. Check output
Weekly, inspect the air filters; clean, repair, or
replace them as necessary.
Annually, open the blower or compressor and
inspect for internal erosion or deterioration;
repair as necessary. Paint exterior surfaces.
Maintenance operation frequencies and the
schedule of inspections for aeration equipment are
shown in appendix III, table G.
Q21. Waterfall-type of aerators use what type of
action to areate water?
Q22. What reaction will occur when water is poured
into sulfuric or chromic acid?
Q23. Chlorine gas injection into the air line header of
injection nozzles will reduce what condition?
SAFETY AND EMERGENCIES
LEARNING OBJECTIVE: Recognize and
understand basic safety procedures for use,
handling, and storage of water treatment
chemicals. Understand first aid for chlorine
The operation of water treatment plants is a
hazardous occupation, with dangers from noxious
gases and vapors, physical injury, and infections.
Work should be carried on only under the supervision
of an experienced workman or operator who is trained
in first aid and is familiar with the hazards of the work.
Specific precautions in handling ammonia,
chlorine, and chlorine-yielding compounds were
shown in an earlier chapter on water treatment plants.
A number of chlorination safety precautions are given
Provide self-generating oxygen-breathing
apparatus or self-contained oxygen-breathing
apparatus designed to cope with chlorine.
Maintain only the supply of chlorine in any
chlorinator room that will do for normal daily
demands. Store the main supply in a detached
noncombustible building or in a fireproof room
which is vented only to the outside and which is
separated from the main part of the building.
Keep the chlorinator and chlorine storage.
buildings or rooms locked to prevent the
entrance of unauthorized personnel and restrict
these areas from any other use.