School of Chemistry, Federal University of Rio de Janeiro, Cidade Universitária, Av. Athos da Silveira Ramos, nº 149, Bloco E, Sala 109, Rio de Janeiro, RJ, 21941-909, Brazil.
Environ Sci Pollut Res Int. 2023 Jan;30(4):10830-10840. doi: 10.1007/s11356-022-22896-y. Epub 2022 Sep 10.
Microbiologically influenced corrosion (MIC) behavior of the AISI 1020 carbon steel caused by consortia of nitrate-reducing prokaryotes (NRP) and sulfate-reducing prokaryotes (SRP) was investigated separately in hypersaline seawater conditions. Microbiological analysis, surface images, characterization of corrosion products, weight loss, and electrochemical measurements were employed to monitor the corrosion process for 10 days at 40 °C. Compared to abiotic corrosion (control), the extent of corrosion was more aggravated in the conditions with microbial consortia. It corroborates the critical role of microbial activity in corrosion processes in natural and industrial environments since microorganisms are widely spread. Corrosion rates obtained from Tafel extrapolation were statically equal for both microbial consortia (0.093 ± 0.009 mm.y); however, the maximum pit depth on the steel surface subjected to NRP-MIC was about 25% deeper (48.5 µm) than that caused by SRP-MIC (32.6 µm). In contrast, SRP activity almost doubled the number of pits on the steel surface (2.7 × 10 ± 4.1 × 10 pits.m), resulting in more weight loss than NRP activity. In addition, SRP cells formed nanowires to support direct electron uptake from steel oxidation. This research contributes to the understanding of steel corrosion mechanisms in hypersaline environments with the prevalence of NRP or SRP, as oil reservoirs undergo nitrate injection treatments.
在高盐度海水中，分别研究了硝酸盐还原菌（NRP）和硫酸盐还原菌（SRP）共生体对 AISI 1020 碳钢的微生物影响腐蚀（MIC）行为。采用微生物分析、表面图像、腐蚀产物特性、失重和电化学测量等方法，在 40°C 下监测了 10 天的腐蚀过程。与非生物腐蚀（对照）相比，在有微生物共生体的条件下，腐蚀程度更为严重。这证实了微生物活性在自然和工业环境中的腐蚀过程中的关键作用，因为微生物广泛存在。从 Tafel 外推获得的腐蚀速率在两种微生物共生体之间是静态相等的（0.093±0.009 mm.y）；然而，在 NRP-MIC 作用下钢表面的最大蚀坑深度（48.5 µm）比 SRP-MIC 作用下的深度（32.6 µm）深约 25%。相比之下，SRP 活性几乎使钢表面的蚀坑数量增加了一倍（2.7×10±4.1×10 个蚀坑.m），导致的失重比 NRP 活性多。此外，SRP 细胞形成纳米线以支持从钢氧化中直接获取电子。这项研究有助于了解在油藏进行硝酸盐注入处理时，NRP 或 SRP 普遍存在的高盐环境中的钢腐蚀机制。
