Transcript Wastewater Treatment in Kansas, USA

Wastewater Treatment
in Kansas, USA
Facts about Kansas
Total Population: 2,764,075
 Capital City: Topeka
Less than 1% of United States Population
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The mission of the Environmental Protection Agency is to
protect human health and the environment. Since 1970, EPA has
been working for a cleaner, healthier environment for the
American people.
EPA leads the nation's environmental science, research,
education and assessment efforts
Research grants and graduate fellowships
Over 40 voluntary pollution prevention programs and energy
conservation efforts
Headquartered at Washington, DC.
EPA is led by the Administrator, who is appointed by the
President of the United States
EPA Clean Water Act 1977
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Primary federal law in the United States
governing water pollution.
Goals: Reduce direct pollutant discharges into
waterways, finance municipal wastewater
treatment facilities, and manage polluted runoff
set water quality standards for all contaminants
in surface waters
Great Lakes Critical Programs Act of 1990
Kansas WWTP- North Topeka
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Wastewater Treatment Plant
Wastewater: water that has been used for domestic or
industrial purposes
Wastewater Treatment: the physical, chemical, and
biological processes used to remove pollutants from
wastewater before discharging it into a water body
Completed May 1996, at a cost of 29.3 million dollars
State-of-the-art 12 million gallon per day (mgd)  0.5 m /s
Complete Mix Activated Sludge Process (CMAS).
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Treatment Stages for Kansas WWTP
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Preliminary Treatment :
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The 1st step in treating the wastewater
entering the treatment plant is to remove the
debris (rags, sticks, etc.) and grit (sand &
gravel) by a bar screen.
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Strained because the debris might interfere
with the operation of pumps, valves, and
other equipment in the wastewater treatment
process down stream.
This debris (screenings), which has been
removed, is then sent to the landfill for burial.
Top to bottom view of bars in the
channel.
The 2nd step is removal of the grit
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Material is removed in the cyclone separator
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acts as a centrifugal separator
Heavy particles (grit and inorganic) are
separated from organic particles and
wastewater.
Heavier material is sent to the landfill
Screened material caught on the bar screen is raked up
and dumped into wheelbarrow for burial at landfill.
Treatment Stages for Kansas WWTP
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Primary Treatment:
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parallel tanks (clarifiers)
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enables the separation of heavy solids
and floating solids from the wastewater.
The clarifiers are sized to allow enough
quiescent time (typically 2-4 hours) so
that the fecal matter can settle out and
so the oil & grease can float.
The skimmer makes a revolution every
half hour to skim grease and floatables.
The “heavier than water” fecal matter
that settles to the bottom of the clarifier
is removed and the oil & grease is
skimmed off the top
Approximately 60 percent of the solid
organic material is removed in the
primary.
This constitutes about 30 percent of
the biodegradable material in the
wastewater.
Primary Clarifier with skimmer for oil & grease removal.
Empty primary clarifier showing solids collector mechanism
in tank bottom.
Treatment Stages for Kansas WWTP
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Secondary Treatment:
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Utilizes naturally occurring microbes to
remove the remaining waste material
Completely Mixed Activated Sludge (CMAS)
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Microbes remain in contact with the wastewater
for about 12 hours
Remove 90 percent of the waste.
Microbes reproduce as they remove waste &
convert the biodegradable material digested to
the microbial form.
Microbe from the wastewater, and send the
wastewater on to the next process.
3.2 million gallon complete mixed activated sludge
in aeration basin. (detention time is c. 6 h)
Clarification Process: removing microbes
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The mixture of wastewater and microbes is
sent on to the secondary clarifiers.
The microbes settle to the bottom of the
clarifier.
Microbes is sent to the solids holding tanks for
removal from the system, and the to secondary
treatment system.
Final clarification basin where the separation of
the microbial mass
Treatment Stages for Kansas WWTP
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Water Treatment Plant Operator
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Daily microbial population vs. incoming
waste material.
Controls the number of microbes in the
system.
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The operator as part of the daily testing
measures the bacterial population by
running a gravimetric test called the
Suspended solids test- gravimetric test to
measure bacterial population
Excess bacteria are sent to the solids
thickening process prior to land
application.
The wastewater leaving the secondary
clarifiers, with already 90 percent of the
original pollutants removed, continues on
to the Disinfection process.
Certified Wastewater Treatment Plant Operator performing a
process measurement.
Treatment Stages for Kansas WWTP
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Why Disinfection/Neutralization is important
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Disinfection: Selective destruction of diseasecausing organisms
Bacteria, viruses, and amoebic cysts.
Disease caused by water borne bacteria includes
typhoid, cholera, paratyphoid, and bacillary
dysentery
Diseases caused by waterborne viruses, which
include poliomyelitis and infectious hepatitis.
Disinfection/Neutralization: Chlorination
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Chlorination used for destruction of pathogenic
and harmful organisms.
Chlorine forms hypochlorous acid, Hypochlorite
ion, & chloramines in water
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good destruction of harmful bacteria
De-Chlorination
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Sulfur Dioxide minimizes toxicity which forms from
chlorination.
Removes the total combined chlorine residual that
exists after chlorination before the treated
wastewater is released to the Kansas River.
Serpentine Channels to reduce short circuiting and
ensure good chlorine contact with the bacteria (disinfection).
A minimum of 30 minutes contact time is built in.
Treatment Stages for Kansas WWTP
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Outfall and Discharge
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Effluent leave the treatment plant to the
Kansas River.
Effluent leaves the plant over a weir which
acts to create a natural aeration
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Adds to dissolved oxygen content.
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necessary for fish and aerobic biota in
order to survive.
After aeration, the effluent goes to a small
drainage ditch where it is directed via the
concrete structure to the Kansas River.
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The wastewater flowing over a discharge weir and
being naturally aerated.
control bank erosion and increase the
velocity of the effluent entering the Kansas
River
facilitating good mixing with the Kansas
River flow.
Diversion structure which funnels discharge to the
Kansas River.
Treatment Stages for Kansas WWTP
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If the Kansas River level rises above flood
stage, the effluent could not be discharged
through the dike as the floodgates would
be closed.
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Effluent from the North Topeka
Wastewater Treatment Plant can be
pumped over the dike via a system of
pumps on the plant site.
Able to pump all the wastewater the plant
is designed to treat (approx. 12 million
gallons per day), but they also are sized
large enough to pump all the storm-water
that will drain from the area.
The three flood pumps for pumping wastewater over the dike
when the Kansas River is in flood stage.
Great Flood of 1993
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April to October 1993
One of America’s most costly and
devastating flood since Great Mississippi
Flood of 1927
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15 billion dollars
Great Flood of 1993