Monitoring of anaerobic microbially influenced corrosion via electrochemical frequency modulation
Monitoring of anaerobic microbially influenced corrosion via electrochemical frequency modulation
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DOI：
10.1016/j.electacta.2013.04.144
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发表时间：
2013-08-30
影响因子：
6.6
通讯作者：
Mayrhofer, Karl J. J.
中科院分区：
文献类型：
--
作者：
Beese, Pascal;Venzlaff, Hendrik;Mayrhofer, Karl J. J.
电化学频率调制（EFM）是一种相当新颖的技术，以监测腐蚀速率在现场，提供直接进入塔菲尔斜率只有轻微的极化。到目前为止，EFM主要应用于纯化学腐蚀体系中的电化学腐蚀监测，主要是均匀腐蚀，但它也有很大的潜力，监测微生物影响的腐蚀（MIC）。因此，在这项研究中，由不同的硫酸盐还原菌（SRB）的培养物诱导的MIC进行监测与EFM，并从线性极化电阻（LPR）和测量的自由腐蚀电位E-corr的结果进行了比较。在小规模的生物反应器与三个电极设置的电化学结果进行了补充化学分析和SEM观察。具有高腐蚀速率的SRB与无腐蚀性但仍消耗H-2的对照SRB、无菌对照和非生物硫化物腐蚀对照进行了比较。在所有情况下，只要该系统是基于均匀腐蚀，用EFM和LPR确定的腐蚀速率都是准确和精确的。然而，随着局部腐蚀的发生，这两种方法都无法预测准确的速率。与其他电化学腐蚀速率测量不同，EFM的优势在于提供不同频率下电流响应的指示比率，即所谓的因果关系因子，这允许识别腐蚀系统的变化，从而评估所获得结果的准确性。因此，EFM是一种很有前途的电化学腐蚀监测技术的MIC在基础和应用研究。(c)2013爱思唯尔有限公司保留所有权利。
Electrochemical frequency modulation (EFM) is a rather novel technique to monitor corrosion rates in situ, providing direct access to Tafel slopes with only minor polarization. So far EFM has been applied mainly for electrochemical corrosion monitoring in purely chemical corrosion systems with predominant uniform corrosion, but it has also great potential for monitoring microbially influenced corrosion (MIC). Thus, in this study MIC induced by different cultures of sulfate-reducing bacteria (SRB) was monitored with EFM, and compared to results from linear polarization resistance (LPR) and measurements of the free corrosion potential E-corr. The electrochemical results obtained in small scale bioreactors with a three electrode setup were complemented by chemical analysis and SEM observations. SRB featuring high corrosion rates were compared to non-corrosive but still H-2-consuming control SRB, sterile controls and abiotic sulfide corrosion controls. Corrosion rates determined with EFM and LPR were accurate and precise in all cases as long as the system was based on uniform corrosion. However with the onset of localized corrosion both methods fail to predict accurate rates. Unlike other electrochemical corrosion rate measurements, EFM has the advantage to provide indicating ratios in the current response at different frequencies, so-called causality factors, which allow identifying changes in the corrosion system and therefore assessing the accurateness of the obtained results. As a consequence EFM is a promising electrochemical corrosion monitoring technique for MIC in fundamental and applied studies. (c) 2013 Elsevier Ltd. All rights reserved.