海洋环境腐蚀与生物污损重点实验室知识库

海洋环境是一个十分复杂的系统，腐蚀性微生物也是无处不在，除海洋复杂环境中的物理和化学因素造成的腐蚀影响外，由腐蚀性微生物导致的金属微生物腐蚀问题也广泛存在，成为海洋工程设施材料安全生产所面临的一大严峻挑战。目前，杀菌剂以其经济、简便及性能优良等特点被广泛应用在各行各业中。但是，现如今杀菌剂多仅以杀菌为目的，人们对杀菌机理的认识相对匮乏。因此，本研究从杀菌机理探讨的角度出发，分析不同浓度的杀菌剂2,2-二溴-3-次氮基丙酰胺（DBNPA）对硫酸盐还原菌（SRB）诱导X80管线钢腐蚀行为的影响，探究DBNPA与鼠李糖脂（RL）复配时的杀菌作用机理，同时进一步对实际工况进行模拟，对比探讨生物膜形成后杀菌混合物的杀菌机制，从而为杀菌剂的实际应用提供一定的参考。主要结论如下，

（1）研究了不同浓度DBNPA对SRB诱导X80管线钢腐蚀行为的影响，并对DBNPA的腐蚀抑制机理进行了探讨。通过DBNPA梯度浓度的设置发现，当c_DBNPA≤300 ppm时，随着DBNPA浓度的升高，腐蚀速率逐渐降低，抑制了SRB的增殖及在金属表面的固着，减缓了金属材料的局部腐蚀。但当DBNPA浓度提高至1000 ppm时，检测到了Fe₂O(PO₄)和Fe(PO₃)₃特征腐蚀产物，X80试片的腐蚀速率大大加快，SRB的存在与否不再是腐蚀的控制因素，X80管线钢的腐蚀形式转变为全面腐蚀。

（2）研究了DBNPA与RL复配对SRB诱导X80管线钢腐蚀行为的影响。在SRB体系中添加150 ppm DBNPA与500 ppm RL时，X80管线钢腐蚀速率降低了77.8%，试片表面固着细菌数量减少了3个数量级，腐蚀电流密度降低了84.7%，杀菌性能优于仅含DBNPA或RL的体系，显著抑制了X80管线钢的局部腐蚀。DBNPA可影响SRB中影响代谢的成分，有效抑制SRB的增殖；RL具有分散SRB生物膜的作用，并且可吸附在金属的表面形成阻隔膜，二者的协同作用可有效抑制X80试片的MIC。

（3）研究了生物膜形成后杀菌混合物对SRB诱导X80管线钢腐蚀行为的影响。向SRB腐蚀5天后的体系中加入杀菌剂或杀菌混合物，含150 ppm或300 ppm DBNPA的体系中，X80管线钢的腐蚀速率分别降低了12.5%、19.8%。含150 ppm DBNPA和 500 ppm RL杀菌混合物的体系的腐蚀速率降低了64.7%，腐蚀电流密度降低了78.4%。与前述实验（研究内容2）相比，在相同浓度的杀菌剂条件下，已形成的生物膜对外界杀菌剂起到了一定程度屏蔽和抵抗的作用，使得杀菌剂及杀菌混合物的腐蚀防护效果欠佳。

因此，本文从实际工程应用的角度出发，对不同浓度杀菌剂下SRB诱导的X80管线钢的腐蚀行为进行了研究；同时对杀菌剂及杀菌混合物的作用机理进行了探讨，并对杀菌效果进行了对比分析；另外，对实际环境中设备管道表面生物膜已形成的情况进行模拟，对比分析杀菌剂及杀菌混合物的缓蚀抑菌作用机制，有助于为实际工况中杀菌剂的选择与使用提供一定的参考，从而实现高效、科学及长效防腐。

The marine environment is a very complex system, corrosive microorganisms are also ubiquitous, so in addition to facing the impact of physical and chemical factors, the corrosion problem caused by corrosive microorganisms is also widespread, which has become a major challenge for the safe production of in-service production equipment. At present, people have developed a variety of anti-corrosion technologies, but biocides are widely used for their economic, simple and excellent properties. However, nowadays, most biocides only aim at sterilization, and people's understanding of sterilization mechanism is relatively poor. Therefore, from the perspective of discussion on bactericidal mechanism, this study analyzed the influence of different concentrations of biocide 2,2-dibromo-3-nitropropionamide (DBNPA) on the corrosion behavior of sulfate-reducing bacteria (SRB), explored the bactericidal mechanism of DBNPA combined with rhamnolipid (RL), and further simulated the actual working conditions. The bactericidal mechanism of the bactericidal mixture after biofilm formation was compared and discussed, so as to provide a certain reference for the practical application of biocides. The main conclusions are as follows.

(1) The impact of varying concentrations of DBNPA on the corrosion behavior of X80 pipeline steel induced by SRB was investigated, and the mechanism of corrosion inhibition by DBNPA was analyzed. By establishing a gradient concentration of DBNPA, it was observed that when c_DBNPA≤300 ppm, an increase in DBNPA concentration led to a gradual decrease in corrosion rate, inhibiting the proliferation and adhesion of SRB on the metal surface, thereby slowing down local metal material corrosion. However, at a concentration of 1000 ppm, characteristic corrosion products Fe₂O(PO₄) and Fe(PO₃)₃ were detected, resulting in a significant acceleration in the corrosion rate of the X80 coupons. The presence or absence of SRB no longer played a controlling role in corrosion; instead, comprehensive corrosion became the dominant form for X80 pipeline steel.

(2) The combined effect of DBNPA and RL on the corrosion behavior of X80 pipeline steel induced by SRB was investigated. The addition of 150 ppm DBNPA and 500 ppm RL to the SRB system resulted in a 77.8% reduction in the corrosion rate of X80 pipeline steel, a three order of magnitude decrease in the number of sessile bacteria on the coupon surface, an 84.7% reduction in corrosion current density, and superior bactericidal performance compared to systems containing only DBNPA or RL. Local corrosion of X80 pipeline steel was significantly inhibited. DBNPA can impact SRB components that affect metabolism and effectively suppress SRB proliferation, while RL has biofilm-dispersing properties and can form a barrier film when adsorbed onto metal surfaces. The synergistic effect of both compounds effectively inhibits MIC on X80 coupons.

(3) The impact of a bactericidal mixture on the corrosion behavior of X80 pipeline steel induced by SRB after biofilm formation was investigated. Addition of biocide or bactericidal mixture to the system after 5 days of SRB corrosion resulted in a reduction in the corrosion rate of X80 pipeline steel, with reductions of 12.5% and 19.8% observed for 150 ppm and 300 ppm DBNPA, respectively. Furthermore, the addition of 150 ppm DBNPA and 500 ppm RL led to a reduction in the corrosion rate by 64.7% and a decrease in the corrosion current density by 78.4%. In comparison with previous experiments (research content 2), it was found that under equivalent biocide concentrations, formed biofilms provided some level of shielding and resistance against external biocides, thereby diminishing their effectiveness.

Therefore, this work investigates the corrosion behavior of X80 pipeline steel induced by SRB under different concentrations of biocides from the perspective of practical engineering application. It also discusses the action mechanism of biocide and bactericidal mixture, compares and analyzes their bactericidal effects. Furthermore, the simulation of biofilm formation on equipment pipeline surfaces in actual environments and comparative analysis of the corrosion and bacteriostatic mechanism of biocide and bactericidal mixture mechanisms are helpful for providing references for selecting and using biocides in actual working conditions to achieve efficient, scientific, and long-term anticorrosive measures.

第1章 绪论    1
1.1研究背景    1
1.2硫酸盐还原菌（SRB）简述    3
1.2.1 SRB来源及特点    3
1.2.2 SRB生理代谢    3
1.2.3 SRB腐蚀机理研究进展    5
1.3 X80管线钢应用简述    7
1.4杀菌剂简述    8
1.4.1杀菌剂分类    8
1.4.2 DBNPA应用介绍    9
1.4.3 RL应用介绍    9
1.4.4杀菌剂应用现状    10
1.5选题依据与研究内容    12
1.5.1选题依据    12
1.5.2研究内容    12
第2章 SRB在不同浓度DBNPA中对X80管线钢腐蚀行为的影响    14
2.1引言    14
2.2材料与方法    15
2.2.1实验仪器    15
2.2.2微生物培养与材料试样    16
2.2.3代谢因子测定    16
2.2.4腐蚀浸泡实验    17
2.2.5腐蚀失重实验    17
2.2.6腐蚀形貌观察    17
2.2.7腐蚀产物元素分析    18
2.2.8电化学测量    18
2.3结果与讨论    18
2.3.1理化代谢因子测定    18
2.3.2腐蚀形貌观察    19
2.3.3腐蚀坑测量    20
2.3.4腐蚀速率测量    23
2.3.5腐蚀产物组成分析    23
2.3.6腐蚀电化学测量表征    30
2.4章节小结    35
第3章 DBNPA与RL复配对SRB诱导X80管线钢腐蚀的影响    37
3.1引言    37
3.2材料与方法    38
3.2.1实验仪器    38
3.2.2微生物培养与材料试样    38
3.2.3 SRB生长代谢因子表征    38
3.2.4 SRB浮游及固着细菌计数    38
3.2.5腐蚀速率及腐蚀坑测定    39
3.2.6腐蚀形貌观察    39
3.2.7腐蚀产物组成表征    39
3.2.8电化学参数测量    39
3.3结果与讨论    40
3.3.1 SRB生理代谢过程    40
3.3.2 SRB在X80表面的附着表征    40
3.3.3腐蚀速率测定    41
3.3.4腐蚀形貌观察    42
3.3.5腐蚀坑测量    44
3.3.6腐蚀产物组成分析    46
3.3.7电化学测量表征    49
3.4章节小结    55
第4章 DBNPA与RL复配对已形成SRB生物膜诱导X80管线钢腐蚀行为的影响    56
4.1引言    56
4.2材料与方法    56
4.2.1实验仪器    56
4.2.2微生物培养与材料试样    57
4.2.3 pH及吸光度测定    57
4.2.4 SRB附着表征    57
4.2.5腐蚀速率及腐蚀坑测定    57
4.2.6腐蚀形貌观察    57
4.2.7腐蚀产物组成表征    58
4.2.8电化学测量    58
4.3实验结果与讨论    58
4.3.1 SRB生理代谢过程    58
4.3.2 SRB在X80表面的附着    59
4.3.3腐蚀速率    60
4.3.4腐蚀形貌观察    61
4.3.5腐蚀坑测量    63
4.3.6腐蚀产物元素组成表征    65
4.3.7 SRB影响下X80的腐蚀电化学    71
4.4章节小结    76
第5章 结论与展望    77
5.1主要结论    77
5.2创新点    78
5.3研究展望    78
参考文献    79
附录  全文缩略词表    90
致  谢    91
作者简历及攻读学位期间发表的学术论文与其他相关学术成果    93