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Bdellovibrio bacteriovorus is a gram-negative predatory bacterium which can potentially inhibit microbiologically influenced corrosion by preying on sulfate-reducing bacteria (SRB). However, no researches about the inhibition are reported according to the authors’ knowledge. The purpose of this paper was to investigate the Inhibition effect of B. bacteriovorus on the corrosion of X70 pipeline steel induced by SRB.

The effect of B. bacteriovorus on the growth of SRB was studied by measuring the optical density at 600 nm (OD600) and sulfate concentration in culture medium. X70 pipeline steel was used as the test material to investigate the anti-corrosion effect of B. bacteriovorus on SRB by conducting electrochemical analysis (including Tafel polarization curves and electrochemical impendence spectroscopy) and weight loss measurement.

B. bacteriovorus could inhibit the growth of SRB in culture medium by its predation on SRB, which led to decrease of OD600 value and increase of sulfate concentration. The results of electrochemical analysis indicated that B. bacteriovorus had positive inhibition efficiencies on SRB-induced corrosion of X70 pipeline steel. Moreover, corrosion rate of X70 pipeline steel was declined from 19.17 to 3.75 mg·dm-2·day-1 by the presence of B. bacteriovorus.

This is the first report about using B. bacteriovorus to inhibit the corrosion induced by SRB. Compared to other anti-corrosion methods, the microbial inhibition methods exhibit more considerable application value due to its low cost, high efficiency and non-pollution.

Sulfate-reducing bacteria (SRB) are recognized by scholars as the most important class of bacteria leading to corrosion of metal materials. It is important to use the properties of microorganisms to inhibit the growth of SRB in the corrosion protection of metal materials and to protect the environment.

In this work, the behavior of anaerobic Thiobacillus denitrificans (TDN) intracellular enzyme inhibition of SRB corrosion of EH36 steel was investigated with electrochemical impedance spectroscopy, biological detection technology and X-ray photoelectron spectroscopy.

Results showed that the SRB crude intracellular enzyme affected the corrosion behavior of EH36 steel greatly and the purified TDN intracellular enzyme inhibits SRB intracellular enzyme corrosion to EH36 steel.

A perfect enzyme activity inhibition mechanism will provide theoretical guidance for the selection and application of anticorrosion microorganisms, which is of scientific significance in the field of microbial anticorrosion research.

This paper aims to investigate the anti-biocorrosion performance and mechanism of the Cu-bearing carbon steel in the environment containing sulfate-reducing bacterial (SRB).

The biocorrosion behavior of specimens with Cu concentration of 0 Wt.%, 0.1 Wt.%, 0.3 Wt.% and 0.6 Wt.% were investigated by immersion test in SRB solution. By examining the prepared cross-section of the biofilm using focused ion beam microscopy, SRB distribution, bacterial morphology, biofilm structure and composition were determined. The ion selectivity of the biofilm was also obtained by membrane potential measurement. Moreover, the anti-biocorrosion performance of the Cu-bearing carbon steel pipeline was tested in a shale gas field in Chongqing, China.

Both the results of the laboratory test and shale gas field test indicate that Cu-bearing carbon steel possesses obvious resistance to microbiologically influenced corrosion (MIC). The SRB, corrosion rate and pitting depth decreased dramatically with Cu concentration in the substrate. The local acidification caused by hydrolyze of ferric ion coming from SRB metabolism and furtherly aggravated by anion selectivity biofilm promoted the pitting corrosion. Anti-biocorrosion of Cu-bearing carbon steel was attributed to the accumulation of Cu compounds in the biofilm and the weaker anion selectivity of the biofilm. This research results provide an approach to the development of economical antibacterial metallic material.

MIC occurs extensively and has become one of the most frequent reasons for corrosion-induced failure in the oil and gas industry. In this study, Cu-bearing carbon steel was obtained by Cu addition in carbon steel and possessed excellent anti-biocorrosion property both in the laboratory and shale gas field. This study provides an approach to the development of an economical antibacterial carbon steel pipeline to resist MIC.

Microbiologically‐influenced corrosion (MIC) is extremely harmful to both the industry and the environment. Sulfate‐reducing bacteria (SRB) are also important: we have to know what they really are and what they really do to us; this means we have to improve our understanding of SRB and their characteristics. MIC is the officially accepted terminology by NACE[1] to address this type of corrosion. It is a kind of corrosion in which effects of certain microorganisms are felt. MIC is still a matter open for discussion: we cannot explain what is really meant by “microbiological” component, i.e. does it express the possibility that some microbial activity observed at corroded sites on metal surfaces may not result from bacterial growth on metal, but rather that chemical or electrochemical attack on the metal may provide a favorable niche for bacteria to grow? Nor can we be sure about our understanding of the importance of working mechanisms and even the types of microorganisms involved in MIC. In order to have a deeper understanding about corrosion caused by sulfate‐reducing bacteria (SRB), we have to know more about SRB themselves. So, after discussing the importance of MIC, we will mainly focus on SRB and their characteristics that may be new and interesting to the reader.

The purpose of this paper is to develop an equation for the synergistic corrosion of SRB and CO₂ based on the D-W model.

The bacterial types in the a and ß pipelines were studied by the most probable number method, and the corrosion morphology of L360 in pipeline water samples was studied by surface analysis. The corrosion rate of L360 was studied using the weight loss method. The gray correlation method was used to calculate the degree of correlation between the influencing factors of corrosion under the synergistic effect of CO₂ and SRB. The curve obtained from PIPESIM software and experiments data was then fitted using multiple non-linear regression method by MATLAB software.

The equation was used to predict the corrosion of the ß pipeline for verification, and it was found that seven out of ten excavation sites were within a 20% error range.

Using the gray correlation method, an equation that considers synergistic corrosion of SRB and CO₂ has been developed based on the D-W model. The equation could be used to predict the corrosion rate of shale gas gathering pipelines through SRB and CO₂ synergistic corrosion.

The purpose of this study is to find the multi-factor influence law of stress, strain rate and sulfate-reducing bacteria (SRB) on X70 pipeline steel in a simulated solution of sea mud and the order of influence of the three factors on X70 steel to develop a scientific basis for pipeline corrosion protection.

This paper studied the effects of stress, strain rate and SRB on the X70 pipeline steel corrosion behavior in simulated sea mud solution through orthogonal testing, electrochemical experiments and morphological observations.

The results of this study showed that stress proved to be the most relevant element for corrosion behavior, followed by SRB and strain rate. At high stresses (301 MPa and 576 MPa), stress dominated the corrosion behavior of X70 pipeline steel. However, at low stress (82 MPa), SRB played the most important role.

Subsea pipelines are in a very complex environmental regime that includes stress, strain rates and SRB, which often cause pipeline pitting and perforation. However, most scholars have only looked into the influence of single factors on metal corrosion. So, the single-factor experimental results of previous studies could hardly be applied to actual working conditions. There is an urgent need to understand the multi-factor influence law of stress, strain and SRB acting together on the pipeline corrosion behavior, especially to determine the dominant factor.

The purpose of this paper is to develop an empirical equation of SRB corrosion based on their metabolic species.

Solution containing SRB metabolic species was simulated using abiotic chemistry approach. Linear polarization technique was used to measure the corrosion rate of X52‐sample in simulated solution containing SRB metabolic products species. The curve obtained from LPR data was then fitted using multiple non‐linear regression method by Minitab 15^® software.

Statistical analysis shows that sulphide and sulphite have significant effect on the X52 corrosion rate.

Using abiotic chemistry approach, an empirical equation that considers SRB metabolic species has been developed. The equation could be used to predict carbon steel corrosion rate by SRB.

This study aims to shed light on the corrosion behavior of X80 steel when sulfate-reducing bacteria (SRB) and permeating hydrogen interact.

In this study, electrochemical tests were conducted between 25 and 55 °C, and the surface morphology of the specimen was observed using scanning electron microscopy and three-dimensional photos. The composition of the oxide film was characterized by X-ray photoelectron spectroscopy (XPS).

Under the condition of 6 MPa simulated natural gas (15% H₂), the content of S-containing compounds (FeS and FeSO₄) in the corrosion products on the surface of the specimen decreases from 60.8% to 54.4%. This finding indicates that hydrogen permeation inhibits the metabolic processes of SRB in this environment. By comparing the hydrogen-uncharged specimen, it was found that under the condition of 6 MPa simulated natural gas (15% H₂) hydrogen charging, the uniform corrosion on the X80 surface was weakened, and the protection of the oxide film on the specimen surface in this environment was better than that without hydrogen charging.

To the best of the authors’ knowledge, most of these existing studies have focused on the effect of hydrogen on the mechanical properties of materials and very little is known about corrosion behavior in the hydrogen environment. In this study, a self-designed small gas phase hydrogen charging device was used to study the X80 surface corrosion behavior in the environment of the H₂-doped natural gas pipeline.

The purpose of this work was to study the corrosion behaviour of X52 steel in the presence of sulphite.

The study was conducted in abiotic solutions containing species typical of sulphate-reducing bacteria (SRB) metabolism. Electrochemical techniques, i.e. linear polarization resistance (LPR), potentiodynamic and electrochemical impedance spectroscopy (EIS), were used to observe the corrosion kinetics and mechanism of X52 steel in the solution containing sulphite. Field emission scanning electron microscope (FESEM) and X-ray photoelectron spectroscopy (XPS) were used to characterize the corrosion products.

LPR and EIS results showed that the addition of sulphite ions to the abiotic solutions increased the rate of X52 steel corrosion. The increase of corrosion rate was due to the increase in the cathodic reaction in the presence of sulphite. It was also observed that sulphite thinned the protective FeS film and caused corrosive species to adsorb on the surface, resulting in an increase in corrosion rate.

This paper discusses the effects of sulphite on the corrosion behaviour of X52 steel in abiotic solution containing species typically produced by the SRB-type metabolic process. Irrespective of the presence of sulphide, sulphite is produced by SRB during their metabolic process. However, as far as is known, no published papers are available that discuss the effect of the presence of sulphite as one of the metabolic products of SRB.

The purpose of this paper is to investigate microbially induced corrosion on stainless steels due to sulfate reducing bacteria sp. Desulfovibrio desulfuricans and correlate it with the composition of extracellular polymeric substances (EPS) of the biofilm formed by these bacteria.

Stainless steels 304L, 316L and 2205 were selected for the test. Modified Baar's media, both control and inoculated, were used as test solutions in anaerobic conditions. The bacteria were identified by scanning electron microscopy and their growth was estimated by bacterial counting. Electrochemical polarization and immersion test were performed to estimate the corrosion rate and the extent of pitting attack. The degree of corrosion and the presence of chemicals present inside/outside pits were determined by SEM/EDS. Biofilm formed on corroded coupons was analyzed spectroscopically to identify its components. An attempt was made to correlate the extent of corrosion with the bacterial concentration and the EPS of the biofilm. The differing corrosion performances of the stainless steels also were compared.

The corrosivity of the solution increased with the addition of SRBs and with increased incubation time. The amount of carbohydrate and protein in EPS was observed to be a minimum when conditions were most corrosive. However, as the corrosivity decreased, these amounts increased. Stainless steel 2205 showed the highest corrosion resistance, followed by 316L and 304L.

This work shows that SRB degrades its own EPS. Further, the extent of microbial corrosion on stainless steel coupons due to the presence of SRB correlates with the carbohydrate and protein contents of the EPS of the biofilm.