电势诱导下电活性硫酸盐还原菌的电子传递过程及腐蚀机理研究

Electroactive sulfate reducing bacteria (SRB) is one of the most important representative marine corrosion bacterium. It was wide spread in water, oil, gas pipeline and ocean engineering. It could obtain electrons directly from metals by electron transfer, causing serious corrosion damage to metals and threatening the safe operation of production activities. Thus, the research of electroactive SRB corrosion mechanism has always been the research hotspot among scholars. In the actual marine environment, steel facilities are often under the protection of the cathodic polarization, in other words, steel facilities were under the potential induction of direct electrical stimulation. However, the changes of the growth metabolism and electron transfer pathway of the electroactive SRB change with different potential induction, and then influencing the corrosion mechanism. Therefore, it is of great significance to study the electron transfer process and corrosion mechanism of electroactive SRB on metals. In this project, we suggested to study the regulation in metabolism changes of electroactive SRB with different induced potentials, and illustrate the electron transfer process of SRB under different potential induction by using electrochemical measurement, metabolic factors detection and other techniques. Analysis on corrosion behavior of metals and corrosion products will be conducted to clarify the corrosion mechanism influenced by SRB under different potential induction. These researches would perfect the corrosion mechanism of microbial induced corrosion and provide significant scientific basis for corrosion protection of marine engineering facilities.

电活性硫酸盐还原菌（SRB）是最重要的代表性海洋腐蚀细菌之一，广泛存在于各种输水、油、气管道和海洋工程中。它能通过电子转移的方式直接从金属中获取电子，对金属造成严重的腐蚀破坏，威胁生产活动的安全运行。因此，电活性SRB腐蚀机理一直是学者们的关注重点与研究热点。鉴于实海腐蚀环境中，钢铁设施却常处于阴极极化的保护下，即钢铁设施处于直接电刺激的电势诱导下。而不同电势诱导会引起电活性SRB的生长代谢和电子传递方式的改变，进而影响金属腐蚀破坏机理。因此，研究电势诱导下电活性SRB的电子传递过程及腐蚀机理具有重要意义。本项目将系统对比研究不同诱导电势下电活性SRB的生长代谢变化规律，利电化学和代谢因子检测等技术探究SRB的电活性，阐明其电子传递过程，在此基础上进行金属的腐蚀行为和腐蚀产物分析，揭示不同诱导电势下SRB的腐蚀机理。研究成果将完善微生物的腐蚀机理，并为海洋工程设施阴极保护提供参考。

硫酸盐还原菌（SRB）是典型的海洋腐蚀性细菌，其代谢产生硫化氢等腐蚀性物质会与金属反应产生化学腐蚀；此外，SRB也能通过直接或者间接的胞外电子传递方式从金属中获得电子加速金属腐蚀，诱导微生物电化学腐蚀发生。本项目首先研究了在金属不同自腐蚀电位下微生物的生长代谢情况和环境因子变化，发现了不同自腐蚀电位的金属与SRB相互作用关系和不同腐蚀机制；通过建立不同诱导电势下生物膜电活性测定方法，进一步研究了不同外加诱导电势下微生物的电活性和金属腐蚀行为，研究证明-0.46 VSCE外加电势诱导下形成的微生物较无外加诱导电势下的生物膜具有更高的生物催化活性，而附着的生物膜对SRB与电极之间的电子传递起主要作用；通过不同环境下X70管线钢在不同电势下的电化学特征，找到金属在不同环境中的最佳阴极保护电位和不同诱导电位下的腐蚀速率。本项目搭建诱导电势下微生物的电活性和金属腐蚀行为的研究体系，建立了多环境因子下SRB生物膜活性和腐蚀机理的测试方法，发现了不同环境中金属腐蚀速率随诱导电势的变化规律，研究结果将有助于厌氧微生物电子传递诱导下的金属腐蚀机制形成更全面的认识，并为海洋工程设施防腐和基础研究提供参考。