Granulated coal ash can effectively
adsorb hydrogen sulfide
*S. Asaoka, T. Yamamoto, S. Hayakawa
K. H. Kim, H. Yamamoto
(EMECS'90)
Major enclosed water bodies in the world
Where is Seto Inland sea?
Japan has 88 enclosed water bodies
Setouchi Net (2007)
Aquaculture criterion:
Fly ash(85~95 %)Bottom ash(5~15 %)
Boiler
Electro dust
collector
Den
itirificatio
n
Desu
lfuriza
tion
Coal thermal power plant
11Mt was produced every year in Japan
15 % cement
GCA
1400~1500℃
(3) What is GCA (Granulated Coal Ash) ?
29.2 Ni0.40Sr
3.2 Cs29.3 Pb1.86P2O5
3.9 Yb34.2 La2.50Na2O
4.2 U34.4 Nd5.68TiO2
5.2 W52.6 Y5.2H
6.7 Hf58.9 Cu6.09K2O
12.7 Th69.7 Ce8.11MgO
14.5 Sc88.9 Zn22.5Fe2O3
34.4 Nb111V27.4C
20.6 Ga200N55.4CaO
27.2 Cr298Zr126Al2O3
28.6 Co329MnO133CO3
28.8 Rb397Ba395SiO2
Trace elements (mg・kg-1-dw)Main elements (g・kg-1-dw)
Table 1 Chemical composition of the granulated coal ash used
in the present study
29.2 Ni0.40Sr
3.2 Cs29.3 Pb1.86P2O5
3.9 Yb34.2 La2.50Na2O
4.2 U34.4 Nd5.68TiO2
5.2 W52.6 Y5.2H
6.7 Hf58.9 Cu6.09K2O
12.7 Th69.7 Ce8.11MgO
14.5 Sc88.9 Zn22.5Fe2O3
34.4 Nb111V27.4C
20.6 Ga200N55.4CaO
27.2 Cr298Zr126Al2O3
28.6 Co329MnO133CO3
28.8 Rb397Ba395SiO2
Trace elements (mg・kg-1-dw)Main elements (g・kg-1-dw)
Table 1 Chemical composition of the granulated coal ash used
in the present study
Table 2-3 Chemical composition of granulated coal ash
used in the present study
29.2 Ni0.40Sr
3.2 Cs29.3 Pb1.86P2O5
3.9 Yb34.2 La2.50Na2O
4.2 U34.4 Nd5.68TiO2
5.2 W52.6 Y5.2H
6.7 Hf58.9 Cu6.09K2O
12.7 Th69.7 Ce8.11MgO
14.5 Sc88.9 Zn22.5Fe2O3
34.4 Nb111V27.4C
20.6 Ga200N55.4CaO
27.2 Cr298Zr126Al2O3
28.6 Co329MnO133CO3
28.8 Rb397Ba395SiO2
Trace elements (mg・kg-1-dw)Main elements (g・kg-1-dw)
Table 1 Chemical composition of the granulated coal ash used
in the present study
29.2 Ni0.40Sr
3.2 Cs29.3 Pb1.86P2O5
3.9 Yb34.2 La2.50Na2O
4.2 U34.4 Nd5.68TiO2
5.2 W52.6 Y5.2H
6.7 Hf58.9 Cu6.09K2O
12.7 Th69.7 Ce8.11MgO
14.5 Sc88.9 Zn22.5Fe2O3
34.4 Nb111V27.4C
20.6 Ga200N55.4CaO
27.2 Cr298Zr126Al2O3
28.6 Co329MnO133CO3
28.8 Rb397Ba395SiO2
Trace elements (mg・kg-1-dw)Main elements (g・kg-1-dw)
Table 1 Chemical composition of the granulated coal ash used
in the present study
Table 2-3 Chemical composition of granulated coal ash
used in the present study
Table 1
(1) Chemical composition of GCA
-13.10.211.6Zn
10--
To investigate hydrogen
sulfide adsorption behavior
onto GCA in terms of utilizing
as a remediation agent of
organically enriched marine
sediments.
Motivation
Pure water :50 mL
Na2S・9H2O
0.1 N-HCl (pH=8.2)
Agitated (25oC)
N2 gas purged
Monitoring H2S and SO42-
Liquid phase (Seawater)
XAFS
Solid phase (G.Coal Ash )
XAFS:X-ray absorption fine
structure spectroscopy
1. Experiments
G. Coal Ash (0.2 g)
0.0
2.0
4.0
6.0
8.0
10.0
0 10 20 30 40 50
Contact Time (hr.)
H2S
(m
g-S
L-1
)
Cont Coal
0
20
40
60
80
100
0 20 40 60 80 100
Contact Time (hr.)
H2S
(m
g-S
L-1
)
Cont Coal●:Control, ■: GCA ●:Control, ■: GCA
Removal rate constant
2. Removal kinetics of H2S-S
Contact time (h) Contact time (h)
C0 (mg L-1) k (h-1)
8 0.043
80(0
Day0 1 2 3 4 5 6 7
H2
S (
mo
l/L
)
0
500
1000
1500
2000
2500
3000
SO
42
- (
mo
l/L
)0
100
200
300
400
GCA (H2S)
Control (H2S)
GCA (SO42-)
Control (SO42-)
Day
C0 G0 C3 G3 C7 G7
Co
ntr
ibu
tio
n (
%)
0
20
40
60
80
100
H2S-S (Liq. phase)
SO42- (Liq. phase)
Adsorption (Sol. phase)
Others
H2S and SO42- ( M) Contribution
3.Time course of H2S and SO42- (Initial 100 mg/L)
Solid phase analyses
GCA Initial
Sulfur
Na2SO3
GCA 10 mg L-1
H2S
GCA 100 mg L-1
H2S
GCA 500 mg L-1
H2S
2465 2470 2475 2480 2485
No
rmal
ized
Inte
nsi
ty (
a. u
.)
X-ray energy (eV)
Sulfur Sulfite Sulfate
X-ray energy (eV)
2460 2465 2470 2475 2480 2485
No
rmal
ized
in
ten
sity
(a.
u.)
MnS
TiS3
Al2S3
CaS
FeS
FeS2
XAFS analyses
4960 4980 5000 5020 5040
No
rma
lize
d in
ten
sity
(a
. u
.)
X -ray energy (eV)
Initial
After adsorbed
TiS3
(6) Ti K edge XANES spectra of GCA
Adsorbed
(mg/g)
Ratio(%)
Sulfate Sulfite Sulfur
0 100 0 0
1.5 89 3 8
9.5 63 4 33
18 21 4 75
X ray energy (eV)
2465 2470 2475 2480 2485
Norm
aliz
ed i
nte
nsi
ty (
a. u
.)
Col 1 vs Col 2
Col 4 vs Col 6
Col 5 vs Col 7
Col 10 vs Col 11
Col 10 vs Col 12
Col 15 vs Col 18
Col 16 vs Col 19
Plot 2
0 mg/g
1.5 mg/g
9.5 mg/g
18 mg/g
Sulfur Sulfite Sulfate
Observed
Curve fitting
3.Identifying sulfur species on the GCA
5.Adsorption maximum of H2S
Adsorbent Capacity
(mg-S g-1)
References
Granulated
Coal Ash
>108 This study
Activated carbon 2.3~71
(H2S gas)
Guo et al., 2007
Xiao et al., 2008
Montmorillonite 0.53~12
(H2S gas)
Nguyen-Thanh
et al., 2005
0
20
40
60
80
100
120
140
160
0 400 800 1200 1600
Cu
mu
lati
ve
ad
sorb
ed H
2S
(mg-S
・g-1
)
Time (hr.)
0
50
100
150
200
250
0 500 1000 1500 2000
H2S
-S(m
g-S
L-1
)
Time (hr)
Conclusion
• Granulated coal ash has high H2S
adsorption capacity since H2S was
adsorbed onto the GCA and oxidized
to sulfur.
• Granulated coal ash can effectively
adsorb hydrogen sulfide.
• Granulated coal ash is one of
promising materials to remediate
coastal marine sediments.
Acknowledgements
I thank organizing committee of EMECS9
for providing us prestigious conference.
Thank you for your attention!
3.Time course of H2S and SO42- (Initial 10 mg/L)
Day
0 1 2 3
H2
S (
mo
l/L
)
0
50
100
150
200
250
300
SO
42
- (
mo
l/L
)0
20
40
60
GCA (H2S) Control (H2S)
GCA (SO42-)
Control (SO42-)
Day
C0 G0 C1 G1 C3 G3
Con
trib
uti
on
(%
)
0
20
40
60
80
100
H2S-S (Liq. phase)
SO42- (Liq. phase)
Adsorption (Sol. phase)
Others
H2S and SO42- ( M) Contribution