海洋铁细菌对紫铜腐蚀行为的影响

Influence on corrosion behavior of copper in marine iron-oxidizing bacteria

摘要:

【目的】研究海洋铁细菌(Iron-oxidizing bacteria, IOB)对铜的腐蚀影响。【方法】采用电化学极化曲线、电化学阻抗谱(EIS)研究紫铜在海洋环境铁细菌影响下的腐蚀行为。【结果】扫描电子显微镜SEM形貌分析结果表明, 在紫铜上附着的铁细菌呈杆状。电化学测试结果表明紫铜在含IOB海水中的腐蚀过程主要受活化极化控制, 有菌海水的活化电阻比无菌海水的小6 000 Ω·cm2, 表明在含IOB的海水中铜发生溶解反应受到的阻滞较小。【结论】IOB的存在导致紫铜的自腐蚀电位变小, 使得紫铜发生腐蚀的倾向变大; IOB也使紫铜的阳极极化曲线塔菲尔斜率和变小, 从而加速了紫铜的腐蚀进程。

Abstract:

[Objective] Influence on corrosion behavior of copper in marine iron-oxidizing bacteria. [Methods] The effects of salinity and microbe on the corrosion behavior of copper were investigated by using open-circuit potential of electrode, polarization curves and electrochemical impedance spectroscopy (EIS). [Results] Results show that the analysis of scanning electron microscopy (SEM) indicated that the iron-oxidizing bacteria on the copper were rod. Electrochemical measurement results show that the control step for corrosion of copper in the culture medium for bacteria (IOB) in seawater is activation polarization process. The resistivity of seawater with bacteria is less 6 000 Ω·cm2 than that of without bacteria. It indicated that the retardation of the copper dissolution reaction in seawater with iron-oxidizing bacteria is small. [Conclusion] The presence of micro-organism (IOB) decrease the open circuit potential and activation polarizability of copper, thus speed up the corrosion process of pure copper.