【作者】 刘玉秀；

【导师】 战广深； 刘贵昌；

【作者基本信息】 大连理工大学 ， 电化学工程， 2002， 硕士

【摘要】 将实地取来的四种环境介质富集培养，置于生化培养箱中（29±1）℃下培养21天，获得硫酸盐还原细菌菌种，并利用最大可能计数法（MPN法）进行计数。利用固体培养基进行菌种提纯，使用干燥器厌氧条件下富集培养，并用冰箱冷藏保存菌种。利用简单染色法和革兰氏染色法进行细菌形貌鉴定，证明得到的细菌属于革兰氏阴性菌。 将实验菌种接种于无菌培养基中，利用失重法、动电位极化法和交流阻抗图谱测量等电化学技术及金相显微镜、扫描电子显微镜等物理检测手段，研究了硫酸盐还原菌的数量与A3钢孔蚀诱发的关系、溶液中Fe²⁺浓度和溶解氧的存在对细菌生长的影响以及这些环境因素与硫酸盐还原细菌对碳钢腐蚀行为的协同影响。研究结果表明，硫酸盐还原细菌的代谢产物中含有酸性物质。在含细菌的培养基中，试样的自腐蚀电位都产生了负移，细菌含量越高，负移的程度越大。接种细菌的培养基中测得的阴极极化曲线比空白的斜率小些，硫酸盐还原细菌有促进阴极去极化过程的作用，而阳极极化曲线的变化相反，极化曲线的斜率比空白的大，硫酸盐还原细菌的存在使阳极过程受阻。接种细菌后A3钢的阳极极化曲线都有一段变化较慢的区域，可能是由于试样表面存在生物膜的缘故，生物膜的存在一定程度上阻碍了腐蚀的进一步的发展。硫酸盐还原菌含量不同，测得的容抗弧的直径不同。细菌含量高的介质中C_d小，R_p大，试样表面形成的生物膜较厚，增大了反应阻力；相反在SRB含量较低的介质中C_d大，R_p小。更多还原

【Abstract】 Testing for Sulphate-Reducing Bacteria (SRB) from four kinds of media was discussed. The numbers of each kind of SRB were counted by Most Probable Number estimate method. By using solid culture medium, SRB was purified and conserved at low temperature. The musculomyces of the Sulphate-Reducing Bacteria was identified with simple staining method and Gram’s staining method. It was showed that the bacteria belong to G".By measuring the polarization curves and electrochemical impedance spectrum as well as the aid of microscope and scanning electron microscope, the correlation between bacterial numbers and corrosion behavior of carbon steel was studied. The influences of the ion of Fe2+ and oxygen on the growth of SRB were also investigated. The results showed that there’re acidic substances during the process of metabolism of Sulphate-Reducing Bacteria. The corrosion potential decreased in the medium inoculated with bacteria. It is detected that the more the concentration of the bacteria, the more negative the corrosion potential. The slope of cathodic polarization curves measured in the medium inoculated with SRB is lower than the one obtained in the medium without bacteria, while the slope of anodic polarization curves is higher than it. It is concluded that the process of anodic polarization was repressed at the presence of Sulphate-Reducing Bacteria. There’s some part of anodic polarization curves changed slowly in the medium of SRB. The results showed that the biofilm could restrain the development of the corrosion when the biofilm was compact on the surfaces of specimens. The diameters of Electrochemical Impedance Spectrum vary with the amount of SRB. When the double-electronic layer capacitance Cd decreased, the polarization resistance Rp increased, which indicated that the biofilm on the surfaces of carbon steel raised the reactive resistance in the medium with higher concentration of bacteria. On the contrary, in the medium inoculated with lower amount of SRB, the Cd is higher and the Rp is lower.更多还原