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4190962 
Journal Article 
Anaerobic electrochemical corrosion rug of mild steel in the presence of extracellular polymeric substances produced by a culture enriched in sulfate-reducing bacteria 
Chan, KY; Xu, LC; Fang, HHP 
2002 
Environmental Science & Technology
ISSN: 0013-936X
EISSN: 1520-5851 
36 
1720-1727 
English 
The corrosion of mild steel in a seawater medium containing extracellular polymeric substances (EPS) produced by sulfate-reducing bacteria (SRB) was studied by electrochemical experiments and atomic force microscopy (AFM). Under anaerobic conditions, the corrosion of mild steel increased up to 5-fold in the presence of a 1% (w/w) EPS solution but in the absence of SRB. The enhanced corrosion is mainly due to the oxidizing power of EPS with a reduction potential of E1/2 at -0.54 V (saturated calomel electrode), which is 0.4 V above that of hydrogen reduction. The electrochemical reduction of EPS provides a couple to iron oxidation, as demonstrated by H-shaped cell experiments in which the steel sample and EPS are not in physical contact but are ionically connected via the solution and electronically connected through an external wire. Fourier transformation infrared spectroscopy and X-ray photoelectron spectroscopy showed that EPS derived from SRB are comprised of 60% proteins, 37% polysaccharides, and 3% hydrocarbons. The XPS results showed that, upon corrosion, polysaccharide components were mostly converted to hydrocarbons. 
• Inorganic Mercury Salts (2)
     Mercurous Chloride
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