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Background Data: |
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Case Study: Wastewater Treatment |
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Location: Southeast District Wastewater Treatment Facility
Jacksonville, Florida |
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The Southwest District Wastewater Treatment Facility, located
in Jacksonville, Florida, with a design flow of 10 MGD, treats
an average of 6 MGD of both industrial and domestic
wastewater. This aerobic wastewater treatment facility
generated an average of 7 tons per day of sludge. |
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Sludge disposal costs for the Southwest District Wastewater
Treatment Facility were above $290,000.00 per year. This
figure does not take man hours, sludge press maintenance, or
polymer usage into account. According to Ed Chatham, Plant
Manager, the true sludge disposal costs may be over
$500,000.00 per year. |
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Scope: |
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It was determined that the use of PX-700TM could reduce the
quantity of sludge generated at the Southwest District
Wastewater Treatment Facility, thus reducing overall sludge
disposal costs. |
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PX-700, a microbial bio-catalyst, was to be used as an
additive at the Southwest District Wastewater Treatment
Facility. |
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The anticipated result from the use of PX- 700TM was to be an
overall reduction of sludge generated by the Southwest
District Wastewater Treatment Facility thereby reducing costs
associated with sludge disposal. |
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Facility personnel gathered pertinent data to analytically
determine the effectiveness of PX-700TM. Records were
maintained and reviewed by Ed Chatham, Plant Manager. |
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Treatment Procedures: |
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On July 8, 1998, PX-700TM was introduced into the aerobic
digester at the Southwest District Wastewater Treatment
Facility. |
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Since the only objective was to eliminate the amount of sludge
generated, and thereby reduce the cost associated with sludge
disposal, the digester was chosen as the injection point.
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165 ounces were injected on a flow proportional bases into the
digester during each 24 hour period; this converts into 0.25
mg/l. |
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To further test the effectiveness of PX-700TM, a second
injection point, with no increase in the total amount of
PX-700TM used, was added to the digester on December 9, 1998.
As of the time of this writing, the dosage amounts and
locations have not changed. |
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Results: |
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The Operators Log at the Southwest District Wastewater
Treatment Facility noted a decrease in the number of loads of
sludge transported out of the facility per day. |
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Facility records indicated that 9 loads per day of sludge were
generated and disposed of prior to use of PX-700TM. Three days
after the initial dosage of PX-700TM the number of loads of
sludge transported off site for disposal decreased to 7 loads
per day. This amounts to a reduction of over 22% in the amount
of sludge generated. |
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Facility records indicate that during the month of November
1998, the Southwest District Wastewater Treatment Facility had
a flow increase of over 600,000 GPD, due to fluctuations in
the number of residents in the area. The additional 600,000
gallons of wastewater only produced 1 additional load of
sludge per day requiring transport and disposal. |
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It quickly became apparent to all involved that the use of
PX-700TM significantly reduced the amount of sludge generated
by the Southwest District Wastewater Treatment Facility. |
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City personnel have indicated that they wish to use PX- 700TM
on a permanent basis. |
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The Southwest District Wastewater Treatment Facility has
continued to use PX-700TM through the date of this writing. |
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Total Cost of Sludge Transport and Disposal |
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Prior to Use of PX-700 |
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$500,000.00 Annually |
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With Use of PX-700 |
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$400,000.00 Annually |
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This amounts to a 20% reduction in the total annual
cost of transport and disposal of sludge. |
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$500,000.00
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Prior to Use
of PX- 700
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With Use of
PX- 700
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$400,000.00
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$300,000.00
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$200,000.00
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$100,000.00
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$50,000.00
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Total Cost of Sludge Generated |
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Prior to Use of PX-700 |
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9 Loads per Day |
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With Use of PX-700 |
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7 Loads per Day |
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This amounts to a 22% reduction in the total amount of
sludge generated |
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9 Loads per Day
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Prior to Use
of PX- 700
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With Use of
PX- 700
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8 Loads per Day
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7 Loads per Day
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6 Loads per Day
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5 Loads per Day
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4 Loads per Day
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3 Loads per Day
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