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 2/12 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 6/12 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 8/12 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 ? 11/12 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 12/12
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