청정석탄(clean coal)을 생산하기 위한 석탄의 미생물 탈황공정에서 석탄 슬러리의 점도를 낮출 수 있는 계면활성제들을 찾기 위하여, coal-water-mixture의 제조에 사용되는 11종의 계면활성제들이 철산화 박테리아인 Thiobacillus ferrooxidans의 ferrous iron 산화에 미치는 영향을 조사하였다. 음이온성 계면활성제인 CWM 1001(polymer sulfonate Ne salt), CWM 1002[formaldehyde condensate of sodium naphthalene sulfonate(n=4-5)], CWM 1102formaldehyde condensate of sodium naphthalene sulfonate(n=10-20)]는 10ppm의 낮은 농도에서도 T.ferrooxidans의 강한 전해물질로 작용하였다. 대부분의 계면활성제들은 10-100ppm의 낮은 농도에는 ferrous iron의 산화를 촉진하였고, 계면활성제의 농도 증가에 따라 ferrous iron 의 산화속도가 급격히 감소하였다. 음이온성 계면활성제인 CWM 1104(formaldehyde condensate of sodium naphthalene sulfonate, n=1)와 CWM1105(sodium polyacrylate), 비이온성 계면활성제인 TW 1020(polyoxyethlene sobitaneoleate)는 1,000ppm까지 ferrous iron의 산화를 다소 촉진하거나 영향이 없었다. 500ppm이상의 Monopol NP 1060(non-ylphenol ethyene oxide adduct)을 첨가하였을 때, ferrous iron의 산화속도가 다소 감소하였다. 이들 네 종류(CWM 1104, CWM 1105, TW1020, NP 1060)의 계면활성제들은 석탄의 미생물 탈황공정에서 고농도 석탄 슬러리의 유동성을 향상시키기 위해 사용이 가능한 것으로 평가되었다.

Influences of a number of surfactants on the oxidation of ferrous iron by Thiobacillus ferrooxidans were investigated. The goal was to select appropriate surfactants for a microbial coal desulfurization process. Anionic surfactants such as CWM 1001(polymer sulfonate Na salt), CWM 1002[formaldehyde condensate of sodium naphthalene sulfonate(n=4-5)], and CWM 1102 [formaldehyde condensate of sodium naphthalene sulfonate(n=10-20)] strongly inhibited the oxidation of ferrous iron to ferric iron by T. ferrooxidans. Most of the surfactants tested slightly promoted the oxidation at low concentrations of 10-100ppm, but significantly inhibited as increasing their concentrations. Other anionic surfactants such as CWM 1104(formaldehyde condensate of sodium naphthalene sulfonate, n=1) and CWM 1105 (sodium polyacrylate), and a nonionic surfactant, TW 1020(polyoxyethylene sobitaneoleate), up to 1,000ppm either had no effect on or slightly promoted the oxidation. The oxidation rate of ferrous iron was slightly reduced when a nonionic surfactant, Monopol NP1060(nonylphenol ethylene oxide adduct), Was added over 500ppm. These surfactants, CWM 1104, CWM 1105, TW 1020, and NP1060, were found to be used to improve the fluidity of coal slurry in a microbial coal desulfurization process with no harmful effects.

Ryu HW, Yoo HJ, Chang YK, Kim SD, Proc. 3rd Asian Conference on Fluidized Bed and Three-Phase Reactors (Chun, H.S. and Kim S.D., eds.) 628-633, Kyoung-Ju, Korea (1992)
Ryu HW, Chang YK, Kim SD, Energy Eng. J., 1, 135 (1992)
Ryu HW, Chang YK, Kim SD, Fuel Process. Technol., 36, 267 (1993) 
Ryu HW, Chang YK, Kim SD, HWAHAK KONGHAK, 31(3), 325 (1993)
Andrews GF, Maczuga J, Biotechnol. Bioeng., 12, 337 (1982)
Andrews GF, Darroch M, Hansson T, Biotechnol. Bioeng., 32, 813 (1988) 
Beyer M, Ebner HG, Klein J, Appl. Microbiol. Biotechnol., 24, 342 (1986)
Beyer M, Ebner HG, Assenmacher H, Frigge J, Fuel, 6, 551 (1987) 
Rinder G, Beier E, Erdoel Kohle, 36, 170 (1983)
Hoffmann MR, Faust BC, Panda FA, Koo HH, Tsuchiya HM, Appl. Environ. Microbiol., 42, 259 (1981)
Lee K, Yen TF, Blazquez ML, "New Filamentous Bacteria for Coal Desulfurization," In Bioprocessing and Biotreatement of Coal (ed. by Donald L. Wise), Marcel Dekker Inc., New York, and Basel (1990)
Wakao N, Mishina M, Sakuai Y, Shiota H, J. Appl. Microbiol., 29, 177 (1983)
Chen CCY, Skidmore DR, "Microbial Desulfurization with Thermophilic Microorganisms," In Bioprocessing and Biotreatment of Coal (ed. by Donald L. wise), Marcel Dekker Inc., New York and Basel (1990)
Chandra D, Mishra AK, "Removal of Sulfur from Assam Coals by Bacterial Means," in Bioprocessing and Biotreatment of Coal (ed. by Donald L. Wise), Marcel Dekker Inc., New York and Basel (1990)
Ehrilich HL, Fox SI, Biotechnol. Bioeng., 9, 471 (1967) 
Lowry OH, Rosebrough NJ, Farr AL, Randall RJ, J. Biol. Chem., 193, 265 (1951)
Silverman MP, Lundgren DG, J. Bacteriol., 77, 642 (1959) 
Dugan PR, Biotechnol. Bioeng., 29, 49 (1987) 
Bos P, Huber TF, Kos CH, Ras C, Kuenen JG, "A Dutch Feasibility Study on Microbial Coal Desulphurization," In Fundamental and Applied Biohydrometallurgy (Lawrence, R.W., Branion, R.M.R. and Ebner, H.G., eds.), pp. 129-150, Elsevier, Amsterdam (1986)
Muir MK, Andersen TN, Metallurgical Trans. B, 8B (1977)