阴极极化与典型海洋微生物对腐蚀的耦合效应研究

Microbe induced corrosion is a most complex and serious in marine corrosion area, and cathodic protection is an essential method for protecting offshore structures. Microorganism directly or indirectly takes apart in corrosion electrochemical process, the coupled mechanism with cathodic polarization is not clear, so appropriate protection potential is argued in practice. .Coupled mechanism of cathodic polarization with typical marine microorganism anaerobic sulfate reducing bacteria (SRB) and aerobic iron-oxidizing bacteria (IOB) will be studied. The rules of strong and week electric current/ electric field intensity changing the growing and activity of SRB, the component and structure of biomembrane will be researched. The inhibiting for SRB corrosion behavior, SRB localized corrosion, and by potentiostatic method and changed potential polarization will be researched by electrochemical methods and SEM/ XPS/ XRD determination; the micro environmental changing will be researched through coupled multi-electrode technology and micro pH sensors. The effecting mechanism of potentiostatic method and changed potential polarization on the electrochemical process, the forming of IOB biomembrane and its biomineralization process will be studied; also, the coupled mechanism on the coordination of SRB and IOB will be focused. .To understand the interaction of cathodic polarization, micro environmental property with the growing, metabolism of SRB、IOB and their biomembrane, to understand the properties and changing of biomembrane/corrosion products when SRB and IOB coexistence, to understand the coupled mechanism of cathodic polarization with marine typical microbe induced corrosion, it has not only important theoretical significance for microbiological corrosion electro chemistry, but also has important application value for marine cathodic protection.

微生物腐蚀是海洋腐蚀中最严重、影响因素最复杂的类型。阴极保护是海洋防止构筑物腐蚀的必要措施，微生物直接或间接参与腐蚀电化学过程，与阴极极化的耦合效应尚不清楚，致使制定的保护电位存在争议。.本课题拟研究阴极极化与海洋典型厌氧硫酸盐还原菌（SRB）/好氧铁氧化菌（IOB）及其共生对腐蚀的耦合效应。研究电流（场）强度对SRB生长、活性和附着生物膜的影响规律；研究恒/变电位阴极极化对SRB腐蚀的抑制、对微环境的改变以及对SRB局部腐蚀的抑制行为；研究恒/变电位阴极极化对IOB电化学过程、生物膜形成及生物矿化过程的改变，与IOB和SRB共生腐蚀的耦合机制。.弄清阴极极化、微环境与SRB、IOB的生长、代谢及其对钢腐蚀的耦合作用规律与机理，SRB、IOB及其共存时生物膜/腐蚀产物的演变，揭示阴极极化与海洋微生物腐蚀耦合效应，不仅对微生物腐蚀电化学具有重要的理论意义，也对海洋阴极保护具有重大的应用价值。

阴极保护是海洋构筑物腐蚀防护的必要措施，微生物腐蚀是微生物直接或间接参与的典型电化学过程，微生物必然与阴极保护电场/电流发生交互作用。针对微生物腐蚀的保护电位多年来一直是有争议的。因此，阴极极化与典型微生物腐蚀的耦合效应，阴极电场以及保护的有效性是本课题需要解决的问题。.本课题研究了阴极极化与海洋典型厌氧硫酸盐还原菌（SRB）/好氧铁氧化菌（IOB）及其共生对腐蚀的耦合效应。研究了SRB对高强钢的应力腐蚀敏感性，研究了电流（场）强度对SRB生长、活性和附着生物膜的影响规律，研究恒/变电位阴极极化对SRB腐蚀的抑制、对微环境的改变以及对SRB局部腐蚀的抑制行为；研究固着和浮游IOB对管线钢的腐蚀过程和贡献，研究恒/变电位阴极极化对IOB电化学过程、生物膜形成及生物矿化过程的改变；研究IOB和SRB共生时的腐蚀机制，研究恒/变电位阴极极化对其共生腐蚀过程的抑制以及针对生物膜与阴极极化过程的耦合机制。.弄清SRB对应力腐蚀敏感性加速的规律，强的阴极极化电场可以抑制SRB的腐蚀；固着IOB对腐蚀的贡献远远大于浮游IOB的腐蚀，阴极极化对IOB腐蚀矿化过程有影响，从而抑制其腐蚀；阴极极化对SRB与IOB共生腐蚀有抑制作用，极化强抑制效果好，对生物膜腐蚀也有一定的保护作用。总之，阴极极化对微生物均匀腐蚀和孔蚀均具有抑制作用，是通过抑制微生物的附着、改变微环境的pH值、优化钙镁沉积层和抑制氧化过程实现的；获得了阴极极化过程中，微环境与SRB、IOB的生长、代谢及其对钢腐蚀的耦合作用规律与机理，SRB、IOB及其共存时生物膜/腐蚀产物的演变，揭示了阴极极化与海洋微生物腐蚀耦合效应。不仅对微生物腐蚀电化学具有重要的理论意义，也对海洋阴极保护具有重大的应用价值。