The full proceedings paper is at: http://www.extension.org/72845 The main objective of this research was to investigate the electrochemical oxidation of swine manure effluent obtained from a primary lagoon for reducing organic and inorganic pollutants.

1. Shafiqur Rahman, Associate Professor
Md Saidul Borhan, Research Specialist
Agricultural and Biosystems Engineering
Electrolysis of Swine Manure Effluents
Using Three Different Electrodes: FE-FE,
AL-AL, and FE-AL
Waste to Worth Meeting, Seattle, April 02, 2015

2. Introduction
 Removal of phosphorus and nitrogen from livestock
liquid manure is a challenge
 Various techniques are used for the treatment of industrial
effluent
 The biological processes are slow, need large area, high
treatment cost, and generates huge sludge
 Electrocoagulation/Electrolysis is a potential treatment
technique for treating wastewater

3. Introduction
 Electrocoagulation/Electrolysis technique uses DC power source
between electrodes immersed in the effluent and coagulant is
generated in situ
 Performance of the electrolysis system depends on wastewater
chemistry, electrodes types, and power applied
 The use of the electrolysis system in treating livestock wastewater
is limited

4. Objectives
 To compare the performance of three different Fe-Fe,
Al-Al, and Fe-Al electrodes to improve the quality of
swine wastewater.
 To determine the effect of current density levels on
total phosphorus (TP), chemical oxygen demand
(COD), and total organic carbon (TOC) removal.
 To estimate the Electrical Energy Consumption
(EEC) per unit volume of effluents treated.

5. Materials and Methods
Swine Effluents
• Obtained from primary lagoon of Swine Research Unit
of NDSU and stored at 4˚C until treated by electrolysis
• Effluents were homogenized and characterized at room
temperature (25 ±2˚C)
Parameters
Measured
concentrations
pH 8.3 ± 0.1
EC (mS cm-1) 6.7 ± 0.1
TSS (mg L-1) 980 ± 50
TP (mg L-1) 35.3 ± 3.1
TOC (mg L-1) 490 ± 13
COD (mg L-1) 1577 ± 110

6. Materials and Methods
System Descriptions

7. Materials and Methods
• Three current density levels 500, 1000 , and 2000 mA/cm2
were applied
• Electrolysis process was continued for 60 min
• Polarity of the electrodes was reversed every 5 min
• Effluents were sampled while electrolysis was in progress
at 5 intervals (5 or 10, 20, 30 or 40, and 60 min)
• Samples were kept overnight to be settled
• Supernatants before and after electrolysis were analyzed
for TP, COD, TOC, pH and EC.

8. Evaluation Criteria
Removal efficiencies (%) for TP, COD, & TOC
𝑅𝐸 =
𝑪 𝒊−𝑪 𝒇
𝑪 𝒊
× 𝟏𝟎𝟎
Where, Ci = Initial concentrations
Cf = Final concentrations
Electrical Energy Consumption (kWh/m3)
𝐸𝐸𝐶 =
𝑽×𝑰×𝒕
𝟑𝟔𝟎𝟎×𝑸 𝒆𝒇𝒇𝒍𝒖𝒆𝒏𝒕𝒔
Where, V = DC voltage applied
I = Current applied (mA)
t = Electrolysis time (s)
Q = Volume of effluents (L)

9. Results and Discussions
Al-AL electrodes
Al-Fe electrodes
Treated samples for 60 min using
different electrodes at 21 mA/cm2
Initial
swine liquid
manure

10. Results and Discussions
Treated samples in test tubes (from
left to right) after 0, 10, 20, 30, 40,
and 60 min of electrolysis using
Al-AL electrodes at 21 mA/cm2
0 10 20 30 40 60 min

11. 0
10
20
30
40
50
60
70
80
90
100
110
0
300
600
900
1200
1500
1800
2100
2400
2700
3000
3300
3600
3900
TPRE(%)at10mAcm-2
Time (s)
Fe-Fe
Fe-Al
Al-Al
TP Removal Efficiency

12. TP Removal Efficiency
0
10
20
30
40
50
60
70
80
90
100
110
0
300
600
900
1200
1500
1800
2100
2400
2700
3000
3300
3600
3900
TPRE(%)at21mAcm-2
Time (s)
Fe-Fe
Fe-Al
Al-Al

13. 0
10
20
30
40
50
60
70
80
90
100
110
0
300
600
900
1200
1500
1800
2100
2400
2700
3000
3300
3600
3900
CODRE(%)at10mAcm-2
Time (s)
Fe-Fe
Fe-Al
Al-Al
COD Removal Efficiency

14. 0
10
20
30
40
50
60
70
80
90
100
110
0
300
600
900
1200
1500
1800
2100
2400
2700
3000
3300
3600
3900
CODRE(%)at21mAcm-2
Time (s)
Fe-Fe
Fe-Al
Al-Al
COD Removal Efficiency

15. 0
10
20
30
40
50
60
70
80
90
100
110
0
300
600
900
1200
1500
1800
2100
2400
2700
3000
3300
3600
3900
TOCRE(%)at10mAcm-2
Time (s)
Fe-Fe
Fe-Al
Al-Al
TOC Removal Efficiency

16. 0
10
20
30
40
50
60
70
80
90
100
110 0
300
600
900
1200
1500
1800
2100
2400
2700
3000
3300
3600
3900
TOCRE(%)at21mAcm-2
Time (s)
Fe-Fe
Fe-Al
Al-Al
TOC Removal Efficiency

17. Energy Consumption
0
10
20
30
40
50
60
70
80
90
100
110
0
5
10
15
20
25
30
35
40
45
50
0
300
600
900
1200
1500
1800
2100
2400
2700
3000
3300
3600
3900
TPREat5mAcm-2CD,%
EEC,kWhm-3
Time, s
EEC_Fe-Fe EEC_Fe-Al EEC_Al-Al
TP_RE_Fe-Fe TP_RE_Fe-Al TP_RE_Al-Al

18. 0
10
20
30
40
50
60
70
80
90
100
110
0
5
10
15
20
25
30
35
40
45
50
0
300
600
900
1200
1500
1800
2100
2400
2700
3000
3300
3600
3900
COD removal, EEC, and treatment times at 21 mA cm-2
CODREat21mAcm-2CD,%
EEC,kWhm-3
Time, s
EEC_Fe-Fe EEC_Fe-Al EEC_Al-Al
RE_Fe-Fe RE_Fe-Al RE_Al-Al

19. Current
Density
(CD)
EC pH
Removal efficiency (%)
Energy
(kWh m-3)
Sludge
(kg m-3)
Specific
Energy
(kWh kg-sludge-1)
TP COD TOC
Fe-Fe electrode
5 5.9 8.4 12 8 22 2.1 2.80 0.75
10 5.9 8.7 88 74 62 6.8 3.20 2.13
21 5.8 8.4 100 79 85 23.8 7.50 3.17
Fe-Al electrode
5 5.5 8.9 54 46 24 1.9 1.62 1.17
10 5.5 8.9 76 54 51 6.6 3.38 1.95
21 5.6 8.8 100 100 74 22.0 7.30 3.01
Al-Al electrode
5 6.7 8.4 100 30 46 2.5 2.43 1.03
10 6.6 8.3 100 38 43 6.8 3.22 2.11
21 6.6 8.4 100 77 69 23.6 4.70 5.02
Removal efficiencies, sludge collected, and EECs at three CDs
(30 min treatment time)

20. Elemental analysis of electrolysis sludge
Parameters Al-Al Fe-Fe Fe-Al
ppm
Ag 0.15c±0.00 1.42a*±0.32 0.85b±0.13
Al 148888a±381787 130c±164 83377b±234644
As 1.23c±0.00 80.74a±21.37 34.75b±6.19
B 31.53a±2.42 30.50a±2.24 26.08a±4.97
Ba 2.27b±1.13 5.56a±1.12 3.94ab±1.17
Ca 12422a±5501 13740a±8522 12969a±5620
Cd 1.44b±0.34 19.44a±7.20 6.16b±2.21
Ce 1.27c±0.83 5.42a±0.22 3.11b±0.347
Co 1.28c±0.24 7.95a±0.98 4.45b±0.30
Cu 33.76b±14.05 58.16a±7.31 54.53a±2.92
Fe 4142c±1234 337640a±81923 172416b±23751
K 6853a±93.57 3720b±595 4236b±617
Li 4.02b±1.24 1.15b±0.23 14.16a±5.00
Mg 6648ab±945 5419b±1317 10224a±3416
Mn 95.83c±26.48 506.60a±56.57 287.29b±9.92
Na 2469a±74 1566b±252 1726b±210
Ni 9.01c±1.93 49.23a±4.55 32.40b±1.45
P 6839a±3738 6917a±6795 11539a±6998
Pb 150.97a±113 1.83b±1.34 49.33ab±12.38
S 5020a±1757 2766a±1515 4144a±1757
Sb 1.51a±0.001 1.51a±0.001 1.51a±0.001
Se 5.84a±0.60 1.56b±0.003 2.48b±0.79
Si 39.23ab±1.84 50.64a±12.02 28.06b±8.13
Sn 2.57a±1.27 4.93a±1.68 3.29a±1.12
Sr 23.64a±11.51 25.81a±12.68 26.20a±11.51
Ti 9.75a±0.45 5.47b±2.18 7.66ab±0.52
Tl 2.36a±0.47 2.65a±0.60 3.33a±1.00

21. Conclusions
TP, COD and TOC removal increased as current
densities and treatment times increased.
Al-Al electrodes consumed the lowest energy (2.5
kWh m-3) at lower current density level (5 mA/cm2),
but high TP removal efficiency (100%)
Energy consumption and sludge produced are directly
proportional to current densities applied to the
electrodes

22. Conclusions
Fe-Al electrodes outperformed Al-Al and Fe-Fe
electrodes in treating COD at similar EEC.
Fe-Fe electrodes outperformed Fe-Al and Al-Al
electrodes in treating TOC at similar EEC.
Electrolysis process deposited significant amount of
elements in the sludge, thus likely to improve
wastewater quality.

23. Acknowledgement
North Dakota Pork Council
State Board of Agricultural Research and
Education (SBARE)

24. Go Bison!!
Questions????