This document summarizes a student research project investigating the use of coal fly ash as an adsorbent for removing color from pulp mill effluent. The research team analyzed how factors like ash dosage, shake speed, contact time, and pH affected color removal efficiency. Equilibrium was reached within 12 hours, and dosage optimization found 175g/L of ash most effective. Adsorption models showed the process was more complicated than simple physical adsorption. The team received a research grant and plans to present findings at conferences. Further studies include analyzing COD levels and running continuous column tests.

1. Faculty Advisor: Dr. George Fu
Team Leader: Matthew Usry
Group Members: Abel Sualevai
Andrew Waters
Taylor Vail
Bernard Scott

2.  Introduction
 Objectives
and Scope
 Materials and Methods
 Results & Discussion
 Conclusions
 Further Studies

3. **Images obtained from Georgia Power

4.  Georgia
Power plants
produce an immense
amount of coal/fly ash
 Physical properties of fly
ash that provide means
for filtration/treatment of
some types of
wastewaters, such as
pulp mill effluent
produced at the
Weyerhaeuser plant.

5.  Effects
of the effluent
on the Environment :
• Harms liver function in
fish
• Decrease levels of
dissolved oxygen
• Loss of aesthetic
beauty
• High concentration of
pollutants

6. •
•
To determine if coal
ash is an effective
adsorbent for color
removal from pulp
mill effluent
Complete data
analysis in order to
provide insight into
large scale
application

7.  The
focus will be on such affection
factors for color removal efficiency:
• The dosage of ash
• Shake speed
• Contact Time
 Kinetic
Study to determine equilibrium
time
 Isotherm study performed to model the
adsorption mechanism

8. 
Thus far only the Batch Absorption
experiment has been run. The
procedure for this is as follows:
1.
Coal ash is added into conical
flasks with raw pulp mill effluent.
2.
The mixture is shaken in a rotary
shaker for a certain time period.
3.
The mixture of pulp mill effluent
and coal ash will then be separated
using a vacuum filter.
4.
The color of raw pulp mill effluent
and the filtrate will be tested using
Spectrophotometer in order to
calculate the color removal
efficiency.

9. Sieve
Analysis
Initial
pH Test
Massing
of Coal
Ash

10. Thermo
Scientific
Shaker
Table
Millipore
Vacuum
Membrane
Filtration
(.45µm)
DR 5000
Spectropho
tometer

11. Vial Color
Comparison and
Storage

12. Measurement
Mass (g)
Preliminary Screening __9/18___
Sample 1
Sample 2
2.0267
2.0204
Average
2.02355
Initial Diluted Color
Reading (Pt-Co)
405
317
404
362
404.5
4
4
4
4
4
4
Initial Color (Pt-Co)
1620
1268
1616
1448
1618
1358
Final Diluted Color
Reading (Pt-Co)
309
307
312
308
310.5
307.5
Dilution Factor
Final Color (Pt-Co)
% Removed
4
1236
23.70
4
1228
3.15
4
1248
22.77
4
1232
14.92
4
1242
23.24
4
1230
9.43
20 g/L
300 RPM
720 min
339.5
Dilution Factor
Dose =
Shake Speed =
Shake Time =
Notes:
Initial pH
7.9
7.9
7.9
Final pH
8.1
8.06
8.08
Initial COD (mg/L)
Final COD (mg/L)
430
442
436
**Initial color reading were after 2
times (5mL:5mL) diltuion. COD is
measure of raw effluent. Mass noted
was added to 100 mL of effluent

13. % Color
Removal
92.78
86.95
60.67
26.47
16.33
Concentration (g/L)
200
150
100
50
20

14. Preliminary Screening __9/18___
Measurement
Sample 1
Sample 2
Mass (g)
2.0267
2.0204
Average
2.02355
Initial Diluted Color
Reading (Pt-Co)
374
371
382
378
378
4
4
4
4
4
4
1496
1484
1528
1512
1512
1498
459
489
464
479
461.5
484
100 g/L
150 RPM
720 min
374.5
Dilution Factor
Dose =
Shake Speed =
Shake Time =
Notes:
Initial Color
Co)
(Pt-
Final Diluted Color
Reading (Pt-Co)
Dilution Factor
2
2
2
2
2
2
Final Color (Pt-Co)
918
978
928
958
923
968
% Removed
38.64
34.10
39.27
36.64
38.96 35.38
Initial pH
7.9
7.9
7.9
Final pH
8.106
7.987
8.0465
Initial COD (mg/L)
Final COD (mg/L)
**Initial color reading were after 2
times (5mL:5mL) diltuion. COD is
measure of raw effluent. Mass noted
was added to 100 mL of effluent

15. % Color
92.64
90.10
79.63
52.60
37.17
Concentration
200
175
150
125
100

16. Color Removal Comparison by RPM
Batch 1 (300 RPM)
Batch 2 (150 RPM)
% Color Removal
Concentration (g/L) % Color Removal
Concentration (g/L)
92.7752
200
92.64065
200
86.94526
150
90.10023
175
60.66714
100
79.62828
150
26.47189
50
52.59843
125
16.3321
20
37.16777
100

17.  Dosage
 Shake
Speed
• Optimal dosage range
• 150 RPM was
was determine to be
between 150 g/L and
175 g/L
• The increase in color
removal hit a plateau
as dosage increased
past 200 g/L
determined to be the
most efficient shake
speed
• Due to the marginal
increase in color
removal at high
dosages for 300 RPM
• Cost effective

18. pH
2
4
6
8
10
12
%color removal
98.98
95.93
94.87
86.95
75.35
74.21

19. Dose = 100g/L
Shake Speed= 300RPM
Shake Time = 720 min

20. Affection Factor Adjustment (Batch #4)
1800
Dosage = 175 g/L
RPM of shaker = 150
Shake Time = 12 hours
1600
Color Units (Pt-Co)
1400
1200
1000
Raw Effluent
800
With Coal Ash (100g/L)
pH adj. only
600
400
200
0
0
2
4
6
8
pH
10
12
14

21.  It
was determined that pH
adjustment was not an appropriate
catalyst for color removal
 Required large volume of acid/base to
adjust pH of effluent
 Harsh nature of extreme pH levels
 pH adjustment provided too large of an
initial color level change
 No
pH adjustment was performed on
Kinetic and Isotherm Studies

22.  Properties
of the
adsorption process
 How quickly color can
be removed by coal
ash
 Determine
equilibrium contact
time

23. Time
(min)
5
10
15
30
60
120
240
360
720
1440
2880
Color Units vs Time
1200
Color Units (Pt-Co)
1000
800
600
400
200
12 hr
0
0
10
20
30
Time (Hours)
40
50
60
Final Color Reading
(Pt-Co)
987
962
949
902
865
719
660
597
348.75
345.75
322
As shown,
equilibrium contact
time is approx. 12
hours

24. 

Determination of equilibrium at
different dosages
Equilibrium models based on
Langmuir and Freundlich Isotherm
patterns
 Describe the nature in which the
adsorptive process takes place

25. Process:

Relates the adsorption of
mono-layer molecules onto a
solid surface area to
concentration of
adsorbate
Langmuir Isotherm
Equation is:
[non-linear]
[Linear]
*note: linear Langmuir
equation is in y=mx+b
form
1/Ce
0.00073
0.001071
0.001718
0.002677
0.004878
0.005563
0.005814
Expected Asorption Rate (q)
19.72386588
mg/g
b
-2.729
Langmuir Isotherm Model
0.12
1/adsorption capacity (1/qe)

1/qe
0.097491
0.019339
0.014456
0.013972
0.014126
0.015801
0.017695
0.1
y = -7.2275x + 0.0507
R² = 0.2583
0.08
0.06
0.04
0.02
0
0
0.001
0.002
0.003
0.004
0.005
0.006
Concentration of Color at Equilibrium (Ce)
0.007

26. Process:
o
Relation of concentration
of a solute on the surface
of the media to the
concentration of solute left
in liquid
Freundlich
Isotherm Equation
is:
[non-linear]
[Linear]
*note: linear Freundlich
equation is in y=mx+b
form, but on log scale
Log Ce
3.136403
2.970347
2.764923
2.572291
2.311754
2.254669
2.235528
K
3.153
1/n
-0.5617
Freundlich Isotherm Model
2.000
1.800
1.600
1.400
log (qe)

log (qe )
1.011
1.714
1.840
1.855
1.850
1.801
1.752
1.200
y = -0.5617x + 3.153
R² = 0.4494
1.000
0.800
0.600
0.400
0.200
0.000
1.5
2
2.5
Log Ce
3
3.5

27. 
Langmuir
 Based on the intercept of the best fit linear regression line, the
expected adsorption capacity of about 19 mg of color units per g
of coal ash

Freundlich
 Freundlich constants (K and 1/n) represent the adsorption
capacity and intensity, respectively
 The expected adsorption capacity for this method was
about 3.1 mg/g and the intensity of the reaction was very
low at -.56

Based on the very low value of correlation coefficient R2,
we could conclude that:
the mechanism of color removal by coal ash could be more
complicated than physical adsorption
chemical reaction could also play an important role.

28. 



Dosage optimization was first performed and was
found to be approx. 175 g/L
Optimal shake speed was found to be 150 RPM as the
difference in color removal of 300 RPM was marginally
greater
Equilibrium contact time was determined to be
approximately 12 hours (720 min) from the Kinetic
Study
The Isotherm models suggested that the adsorptive
process taking place was not efficient and could be
more complicated than physical adsorption and
chemical reaction could also play an important role

29.  Received
Georgia Southern Undergraduate
Research Grant
 Submitted complete abstract of our research
for the “National Conference of Undergraduate
Research at Columbus University” in
Columbus, GA
 Plan to submit abstract and poster for
Undergraduate Research Symposium on our
campus Spring 2014

30.  Adsorption
in terms of COD levels before
and after mixing
 Fixed-bed Continuous Column Study
Column Study Diagram