Transcript Creating Ideal Floc for Instant Startup of a Conical Flocculator CEE 453

CEE 453
Research Project
Chris Garnic
Nolan Rogers
Creating Ideal Floc for Instant Startup of a
Conical Flocculator
Research Goals
To create a working conical flocculator
 Find the proper concentrations of clay and
alum to create floc
 Create a recipe for mixing procedures to
create floc in a jar setup
 Find the best transfer method from jar to
conical flocculator
 Generate acceptable drinking water in a
short time period (Honduras)
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Materials
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Peristalic pump
Mixing Device
Cylinder and cone
apparatus
Solenoid valve
Process Controller for
flow regulation
Pressure sensor to
monitor flow
Assortment of tubing
 Pump to regulate
sludge blanket height
(for prolonged periods
of use)
 Clay, Alum, NaOH
 pH sensor
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Supplying influent to reactor
Delivering influent from the bottom via
small 5 mm existing ports.
 Passing influent down tubing to the
bottom of the cone
 What should the exit velocity of the
influent be?
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Influent
Jar Tests
2 sets of 6 jar tests
were conducted.
 5:1 clay to alum ratio
 Constant 50 mg/L
alum (turbidities
ranging from 2502000 NTU)
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Graph of Jar Test Results
4.5
4
Turbitity (NTU)
3.5
3
2.5
2
1.5
1
0.5
0
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
Clay (g/L)
Figure 5: Blue line shows the 5:1 clay to alum ratio while the pink line shows the
constant 50 mg/L alum solution.
Recipe into the Reactor
Two different methods tested for
performance of recipe in reactor
 Funneling to create instant sludge blanket
without disturbing clean water in the
upper half of the reactor.
 Complete mixing of solution in reactor
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Conical Flocculator
What went wrong…
Upside down funnel inside apparatus
 Flow rate problems (too low)
 Sodium Bicarbonate (NaHCO3) versus
Sodium Hydroxide (NaOH) for pH
adjustment
 Settling basin was too small and
turbulence mixed up settling floc
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Settling Basin
Recipe for Instant Floc
Add water to jar (amount of water would be
25% reactor volume)
 Mix in 12 g/L clay, 2.4 g/L alum
 Adjust for pH by adding 0.87 grams NaOH
(For each gram of alum add .364 grams of NaOH)
 Fast mix solution at 100 rpm for 1 minute
 Slow mix solution at 30 rpm for 20 minutes
 Add solution to reactor (that is already 75% full
of water)
 Completely mix water and solution
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Conclusions
Our recipe for floc produced 2.15 NTU
effluent water
 Drinking water standards could be met via
filtration
 Floc can be produced in a jar test!
 We effectively decreased the startup time
of the conical flocculator to about 0.5
hours.
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Suggestions/Comments
Test different cone angles and sizes
 Test different flow rates
 Test the effects of scaling up (Honduras)
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