Transcript MIZUKEN Global Solutions, Inc.

2012 Japan-Taiwan Symposium on intelligent Green and Orange (iGO) Technology
The Relationship of Genus Bacillus,
Sulfate Reducing Bacteria
and Sulfur Oxidation Bacteria
in the Activated Sludge
Sui Kanazawa
Advanced Environmental Engineering Course
Gunma National College of Technology
1. Presentation Outline
1. Background
the corrosion of sewer pipe, B.Subtilis,
Sulfate Reducing and Sulfur Oxidation bacteria (SRB and SOB)
2. Purpose of this research
3. Materials and Method
4. Result and Discussion
5. Summary
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1. Back ground (1/3)
Corrosion of sewer pipe due to sulfuric acid
http://blog.livedoor.jp/tetsu1982/archives
http://www.mcon.co.jp/kasens.html
• Lifespan : 50 years
only 10~20 years
• Protection : the sheet covering method
△ unworkable
3/12
1. Back ground (2/3)
The mechanism of the corrosion due to SRB
the occurrence of H₂S by SRB
SO₄²⁻ + 2C + 2H₂O→2HCO₃+H₂S
H₂O
the diffusion of H₂S
the formation of sulfuric acid
by SOB H₂S + 2H₂O→H₂SO₄ +4H₂
the corrosion of concrete
Ca(OH)₂ + H₂SO₄ →CaSO₄+2H₂O
H₂S
H₂S
SO₄²⁻
SRB : Sulfate Reducing Bacteria
SOB : Sulfur Oxidation Bacteria
4/12
1. Back ground (3/3)
Bacillus. subtilis
• rod-shaped,
gram-positive bacteria
• exists widely in nature
the inhibition of sewer
odor
the limitation of activity
of Escherichia coli
limitation of SRB?
5/12
2. Purpose
To prove the interaction between
B. subtilis, SRB and SOB
To develop the technique for corrosion
protection of concrete
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3. Materials and Method (1/4)
the activated sludge
a biological floc composed of bacteria
• the night soil treatment plant in Gunma
• membrane separation method
• the activated sludge of a B. subtilis-dominated
• wet sample
• freeze-dried sample
7/12
3. Materials and Method (2/4)
Measurement of the Bacillus. subtilis
4
3
2
1
• dilution at 10³ to10⁷ times
• cultivation for 2 days
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3. Materials and Method (3/4)
Measurement of the SRB
• cultivation for 10 days
• MPN method
9/10
3. Materials and Method (4/4)
Measurement of the SOB
• Starkey medium
• shaking culture for a week
• MPN method
10/12
6. Result and discussion
The number of the colonies
[1] data of the night soil treatment plant
[2] data of municipal wastewater disposal plant
Okutone Amenity Park
freeze-dried sample
liquid sample
data from preceding study
B. subtilis (cells/g )
6.6×10⁷
5.0×10⁷
8.9×10⁷ ～
5.43×10⁸ [1]
SRB(cells/g )
7.9×10⁷
9.2×10⁷
0.5×10⁷ ～
33.6×10⁷ [2]
SOB(cells/g )
6.1×10⁴
• the number of SRB is not small in the activated
sludge of a B. subtilis- dominated
• the sludge was odorless
The activity of SRB was
inhibited by some factor ?
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7. Summary
The number of SRB was not small
especially in the activated sludge of
B. subtilis-dominated.
We need to research
to examine others waste water
treatment plant
to examine the activated sludge of
laboratory scale reactor
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