What is the Difference between CLEAN-FLO
International Wastewater Continuous Laminar Flow Inversion and
Wastewater Aeration?
Before 1970 the Water Pollution Control Federation had
determined that fine bubble bottom air diffusers were by far the
most efficient and energy saving of all types of wastewater aeration
systems. The
problem was that fine bubble diffusers quickly clogged. So the
majority of the wastewater treatment industry went to the less
efficient surface aerators. Surface wastewater aerators not only sit on the
surface, they also oxygenate only the surface water of
wastewater lagoons, leaving the rest of the lagoon water anoxic
(without
oxygen). Most important, in temperate and colder
climates, surface aerators often freeze in the winter,
rendering them useless. Our wastewater aerators have a
unique design that allows us to achieve high capacity water
movement with aeration.
In designing its first wastewater aeration system, CLEAN-FLO tackled all
the toughest problems. Because of the energy crisis, the
wastewater aerator
had to be a fine bubble bottom diffuser. But it had to be
non-clogging. It had to be more efficient than wastewater surface aerators.
It had to remove odor. And it had to
remove
bottom organic
sediment (muck). To achieve these goals, the CLEAN-FLO
wastewater
aeration system
had to be especially engineered to be non-clogging and to have
the following characteristics:
CLEAN-FLO Wastewater Aeration System Characteristics
CONTINUOUS: To accomplish
these great improvements over existing wastewater aeration
systems,
it had to operate continuously without failure.
LAMINAR FLOW: To be the
most efficient of all fine bubble bottom diffusers and not stir
up bottom muck and not mix phosphorus, nitrogen and other
pollutants in the muck into the water column, wastewater
aeration must not create
turbulence. It must create a laminar flow of the water from the
bottom to the surface without mixing bottom water in with the
wastewater lagoon water.
INVERSION: To duplicate
nature, which kept lakes clean for thousands of years, the
CLEAN-FLO wastewater aeration system had to be properly engineered to duplicate
spring and fall turnover, or inversion, of lakes several times a
day. The reason for this is because our wastewater
aerator brings water to the surface where it spreads out in a
thin sheet 0.1 inches thick. Oxygen transfer from the atmosphere
to the wastewater is then much higher than it is in standard
clean water tanks, which have very low surface area.
OXYGENATION: To bind
phosphorus and nitrogen to the bottom sediment instead of
re-suspending it into the water column, the wastewater aeration system had to be
engineered to fully oxygenate the water from surface to bottom.
It also had to oxygenate the bottom so bacteria and insects
could feed on and biodegrade organic sediments and so anaerobic
bacteria would not produce odors and toxic gases.
The CLEAN-FLO
Continuous Laminar Flow Inversion and Oxygenation System
was successfully engineered and designed in 1970, and
accomplished every one of these goals. The system is still today
the only wastewater aeration system to our knowledge capable of doing all these
things. To our knowledge, other than inefficient coarse bubble
diffusers, competitive fine bubble bottom diffuser aerators are
known to quickly clog.
CLEAN-FLO International has two types of wastewater diffusers.
Fine Bubble Diffuser: The
most efficient diffuser is fine bubble, usually non-clogging
microporous ceramic. This is not used in oil-laden water, as the
oil will quickly clog the ceramic. In worst-case conditions in
non-oily water, they may have to be cleaned twice a year, or
replaced once a year.
One severe problem with bottom diffusers is that when they fail,
the entire lagoon has to be drained and people have to wade on
the bottom of the pond to replace defective diffusers.
To avoid this nuisance mess, CLEAN-FLO International developed
self-sinking wastewater diffusers that can be raised and lowered from the
surface.
Medium Bubble Diffuser:
Some companies have developed expensive and energy guzzling
coarse bubble diffusers to avoid the clogging and replacement
problem. CLEAN-FLO International developed an economical
medium
bubble diffuser that is non-clogging. This diffuser can also be
lowered to the bottom and raised back up for inspection.
Improving the efficiency of existing surface aerators,
the CLEAN-FLO waste water diffusers completely mix the entire
lagoon, surface to bottom. This means that a few diffusers can
be placed on the bottom of an already surface-aerated lagoon.
The waste water surface aerators can now oxygenate all the water
in the lagoon, which up to doubles the present efficiency of the
surface aerators. Some of the surface aerators can then be
turned off.
•
If your existing wastewater surface aeration systems are not meeting discharge
standards, adding a few CLEAN-FLO bottom diffusers to your
lagoon will economically and effectively increase oxygen
transfer and save energy costs..
•
If you are set on purchasing wastewater aerators, by all means add
a few CLEAN-FLO wastewater bottom diffusers to the package to
get much more oxygen transfer efficiency at much less capital
and energy cost.
Bottom diffuser
comparison: Carr and Martin1
reported the following oxygen transfer efficiencies for bottom
air diffusers in lake water:
Venturi type: 1.8 lb O2 / hp-hr
Perforated Pipe: 2.2 lb O2 / hp-hr
CLEAN-FLO 4.4 lb O2 / hp-hr
Clean Water and Waste Water Comparisons:
CLEAN-FLO International tested oxygen transfer efficiency in
standard clean water for rubber membrane wastewater diffusers,
and the efficiency was the same as our fine bubble
ceramic diffuser. However, rubber membrane diffusers quickly
clog in wastewater, so that the remaining unclogged holes become
much larger. Then the oxygen transfer quickly drops
considerably. Rubber membrane diffusers are also known to tear.
CLEAN-FLO International measured oxygen transfer of the
microporous ceramic diffusers in standard clean water and found
it to be 1.8 kg / kW-hr.
In waste water, contrary to other wastewater aerators in which oxygen
transfer goes down, the efficiency of the CLEAN-FLO diffuser
increases. This is because the CLEAN-FLO wastewater aeration system moves the bottom
water continuously across the surface of the lagoons.
Oxygen transfer from the atmosphere is added to the oxygen
transfer from the rising bubbles free of energy expense.
Please compare the CLEAN-FLO International diffusers to
the Table 5.1 taken from the Water Pollution Control
Federation.2
|
Aeration Efficiency, kg
O2 / kW-hr |
|
Aerator type |
Standard |
Field |
|
Microporous Ceramic |
1.77 |
3.7 – 7.9 |
|
Medium Bubble |
0.9 |
1.9 – 4.0 |
References
1. Carr, Joseph E. and Dean F. Martin, 1978. Aeration Efficiency
as Means of Comparing Devices for Lake Restoration. Department
of Chemistry, University of South Florida, Tampa, Florida.
Journal of Environmental Science $ Health, A13(1), 73 – 85.
2. Water Pollution Control federation, 1988. Aeration a
Wastewater Process.
Click here for a free estimate for your
wastewater aeration project.
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Wastewater
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Wastewater
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Bukidnon
Resources, Mindanao, Philippines.
CLEAN-FLO International Diffusers prove to be
effective in this application. |
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Bukidnon
Resources, Mindanao, Philippines. |
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