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