Shewanella algae对纯锌腐蚀性能的影响

Effects of Shewanella algae on Corrosion of Pure Zinc

关键词:  微生物腐蚀  锌牺牲阳极  腐蚀电位  海藻希瓦氏菌

Key words:  microbiologically induced corrosion  zinc sacrificial anode  corrosion potential  Shewanella algae bacteria

摘要:

[目的]在室内模拟条件下研究海藻希瓦氏菌(Shewanella algae)对纯锌牺牲阳极腐蚀的影响。[方法]利用微生物分析、交流阻抗测试技术、扫描电镜及荧光显微等方法,测试Shewanella algae的生长曲线、开路电位、电化学阻抗、表面形貌等。[结果]在含细菌体系中,细菌通过代谢活动消耗掉溶解氧,在试样表面形成一层生物膜。该生物膜阻挡了腐蚀介质与试样表面的接触,从而使试样的腐蚀受到抑制。荧光显微镜观察结果表明,浸泡7 d,试样表面形成完整的生物膜,但随着营养物质及氧气的消耗,生物膜逐渐脱落。[结论]该细菌可以使纯锌试样的腐蚀电位升高,并且显著抑制试样的腐蚀。该细菌生物膜的形成需要一定的时间及充足的营养物质和氧气。

Abstract:

[objective] The effects of Shewanella algae on sacrificial anode corrosion of pure zinc were studied under laboratory model conditions.[Methods] The growth curves of Shewanella algae,open circuit potential,electrochemical impedance and surface morphology were tested by means of microbial analysis,impedance spectroscopy,scanning electron microscopy and fluorescence microscopy.[Results] In bacteria-containing systems,bacteria consume dissolved oxygen through the metabolic activities,forming a layer of biofilm on the surface of the sample.The biofilm blocked the contact of the corrosive medium with the surface of the sample,thereby inhibiting corrosion of the sample.Fluorescence microscopy showed that the biofilm gradually formed on the surface of the sample after soaking for 7 d,but gradually abscised with the consumption of nutrients and oxygen.[Conclusion] The results show that the bacteria can make the corrosion potential of pure zinc samples increased,and significantly inhibit the corrosion of the samples.The formation of the bacterial biofilm takes a certain time and plenty of nutrients and oxygen.