海藻希瓦氏菌对Zn-Al-Cd牺牲阳极的腐蚀性能影响  

EFFECTS OF SHEWANELLA ALGAE ON CORROSION OF Zn-Al-Cd ANODE

作　　者：张杰[1] 宋秀霞[1,2] 栾鑫[1,3] 孙彩霞[1,4] 段继周[1] 侯保荣[1] 

机构地区：[1]中国科学院海洋研究所,青岛266071 [2]上海海洋大学水产与生命学院,上海201306 [3]中国海洋大学海洋生命学院,青岛266100 [4]烟台大学化学化工学院,烟台264005

出　　处：《金属学报》2012年第12期1495-1502,共8页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目41006054;中国科学院知识创新工程重要厅向项目KZCX2-EW-205资助~~

摘　　要：从锈层中分离出黄色细菌,经分子生物学技术鉴定为海藻希瓦氏(Shewanella algae,SA)菌.采用分光光度法研究了其生长曲线的变化,发现该细菌的生长分为3个阶段:指数生长阶段、稳定阶段和衰亡阶段.采用电化学交流阻抗技术、扫描电镜和荧光显微技术等方法研究了SA菌对Zn-A1-Cd牺牲阳极材料腐蚀行为的影响.结果表明,含SA菌培养基的试样的开路电位要高于无菌培养基中试样的电位,电荷传递电阻R_(ct)值大于无菌培养基的R_(ct)值,说明该SA菌能够抑制试样的腐蚀.分析原因是细菌在试样表面形成生物膜,隔离了腐蚀介质与试样的接触,同时,细菌的生长消耗了氧气,抑制了腐蚀的发生;试样在含SA体系中,5 d时,其表面覆盖比较致密的生物膜;而在不含细菌的体系中,试样表面有明显的腐蚀坑;试样在含SA体系中7 d时,生成比较完整的生物膜,随着体系中营养物质及氧气的减少,SA菌逐渐减少,11 d后试样表面附着的SA菌所剩不多.Shewanella is a typical iron-reducing bacteria which can reduce insoluble ferric iron to soluble ferrous iron and consume oxygen, being considered as the reasons of corrosion inhibition. The main study on Shewanella algae （SA） is the degradation of environmentally harmful organic compounds and heavy metals, and there are very few reports on the interaction of metal corrosion and SA. In this paper, the bacteria isolated from yellow rust layer were identified as SA by using molecular biology techniques. The growth curve of SA was determined with spectrophotography. The results showed that the growth curve was divided into three phases： exponential growth phase, steady phase and decay phase. The effects of SA on corrosion of Zn-A1-Cd anode were investigated by using electrochemical impedance spectroscopy （EIS）, scanning electron microscopy （SEM） and fluorescence microscopy （FM）. The results showed that corrosion potential for samples exposed to the culture medium containing SAwas higher than that for samples exposed to the sterile culture medium during the whole experiment. Rct value in the culture medium containing SA was much greater than that of anode in the sterile culture medium. The bacteria could inhibit the corrosion of the specimen. The reason was that a biofilm layer was formed on the sample surface and the oxygen was consumed through the metabolic activities of bacteria in the culture medium containing bacteria. The biofilm layer was formed on the 5th day in the culture medium containing bacteria. While in bacteri^free system, obvious corrosion pits and white corrosion products were seen on the sample surface. The complete biofilm was formed on 7th day, and it detached from the sample on llth day because of the exhaustion of nutrients and oxygen, showing that the biofilm formation had a great relationship with the presence of nutrients and oxygen.

关 键 词：希瓦氏菌 牺牲阳极 电化学阻抗谱 分子生物学 腐蚀 

分 类 号：TG171[金属学及工艺—金属表面处理]