| 摘要: |
| 为了揭示海洋生物膜形成对金属腐蚀的影响,描述了在不锈铜上形成的海水生物膜,制备了伏安微电极,并测量生物膜中氧化还原化学成分如溶解氧、过氧化氢、锰和硫在不同位置的垂直分布。结果表明,生物膜中存在溶解氧的垂直浓度梯度。在溶解氧浓度小于10μmol/L 条件下,生物膜中的某些位置出现过氧化氢和锰离子,在无氧条件下,生物膜中有硫化物出现,这些化学成分表明生物膜中确实有锰氧化还原菌或者硫酸盐还原菌的活动迹象。生物膜在固体表面的分布是不均匀的,浓差电池或者生物极化作用的存在意味着生物膜的形成可能加速金属基体表面的局部 |
| 关键词: 生物膜 微电极:溶解氧 金属腐蚀 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目(40476035);;厦门大学科研基金资助项目 |
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| Marine biofilm formation and its effect on metal corrosion |
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| Abstract: |
| Microbial cells attach to almost any surface submerged in an aquatic environment.The immobilized cells grow,reproduce,and produce extracellular polymers,forming a tangled matrix of fibers,which provide an assemblage termed a biofilm.The thickness of the biofilm may vary from tens to thousands of micrometers depending on the property of the solid surface,seawater quality,and exposure conditions.This study grew marine biofilms on stainless steel surfaces and constructed voltammetric microelectrodes to measure chemical microprofiles within the biofilms.The purpose is to provide chemical evidences for elucidating the effect of biofilm formation on metal corrosion.It was found that biofilms formed on metal surfaces were heterogeneous both horizontally and vertically.There were oxygen concentration gradients across the thickness of biofilms. Peroxide and Mn~(2+) were found within the biofilms under low oxygen (<10 μ mol/L) conditions,and sulfide was detected at anoxic conditions at the depths of biofilms.These chemical evidences indicated that there were manganese oxidation and reduction microbes and sulfate-reducing microbes living in the biofilms.It was suggested that biofilm heterogeneity could promote localized corrosion at the metal substratum through differential concentration cells and polarizations. |
| Key words: biofilm microelectrode dissolved oxygen metal corrosion |
