Abstract The microbiologically influenced corrosion (MIC) of zinc and galvanized steel caused by a sulfate reducing bacterium (SRB) was investigated. After 7 days of incubation of Desulfovibrio vulgaris in 125 mL anaerobic vials (100 mL culture medium) at 37 °C, the sessile cell coverage on the galvanized steel was slightly higher than that on pure zinc: (1.9 ± 0.2) × 109 cells/cm2 vs. (9.0 ± 1.8) × 108 cells/cm2. The weight losses for galvanized steel and pure zinc were 31.5 ± 2.5 mg/cm2 and 35.4 ± 4.5 mg/cm2, respectively, which were 101 higher than that for carbon steel. The corrosion current densities of galvanized and pure zinc were 25.5 μA/cm2 and 100 μA/cm2, respectively after the 7-day incubation, confirming that galvanized steel was less prone to SRB MIC despite having a slightly higher sessile cell count. In both cases, the corrosion product was mainly ZnS. Three MIC mechanisms were possible for the severe corrosion against the two metals. Extracellular electron transfer MIC (EET-MIC) was thermodynamically favorable for zinc. Furthermore, in the presence of Zn coupons, H2 evolution in the headspace was 5.5 times higher than without Zn coupons, which suggested that proton attack and/or H2S attack also occurred in the corrosion process.

中文翻译：

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硫酸盐还原菌 Desulfovibrio vulgaris 对锌和镀锌钢造成严重的微生物腐蚀

摘要 研究了硫酸盐还原菌 (SRB) 对锌和镀锌钢的微生物影响腐蚀 (MIC)。Desulfovibrio vulgaris 在 125 mL 厌氧小瓶（100 mL 培养基）中在 37 °C 下孵育 7 天后，镀锌钢上的固着细胞覆盖率略高于纯锌上的：(1.9 ± 0.2) × 109 个细胞/ cm2 与 (9.0 ± 1.8) × 108 个细胞/cm2。镀锌钢和纯锌的失重分别为 31.5 ± 2.5 mg/cm2 和 35.4 ± 4.5 mg/cm2，比碳钢高 101。经过 7 天的培养，镀锌和纯锌的腐蚀电流密度分别为 25.5 μA/cm2 和 100 μA/cm2，这证实了尽管固着细胞数略高，但镀锌钢不太容易发生 SRB MIC。在这两种情况下，腐蚀产物主要是硫化锌。对这两种金属的严重腐蚀可能存在三种 MIC 机制。细胞外电子转移 MIC (EET-MIC) 在热力学上对锌有利。此外，在存在 Zn 试样的情况下，顶部空间中的 H2 释放量比没有 Zn 试样时高 5.5 倍，这表明在腐蚀过程中也发生了质子攻击和/或 H2S 攻击。