Presence Of Sulfate-reducing Bacteria Research Articles

How Often Should Microbial Contamination Be Detected in Aircraft Fuel Systems? An Experimental Test of Aluminum Alloy Corrosion Induced by Sulfate-Reducing Bacteria.

Microbial contamination in aircraft fuel-containing systems poses significant threats to flight safety and operational integrity as a result of microbiologically influenced corrosion (MIC). Regular monitoring for microbial contamination in these fuel systems is essential for mitigating MIC risks. However, the frequency of monitoring remains a challenge due to the complex environmental conditions encountered in fuel systems. To investigate the impact of environmental variables such as water content, oxygen levels, and temperature on the MIC of aluminum alloy in aircraft fuel systems, orthogonal experiments with various combinations of these variables were conducted in the presence of sulfate-reducing bacteria. Among these variables, water content in the fuel oil demonstrated the most substantial influence on the corrosion rate of aluminum alloys, surpassing the effects of oxygen and temperature. Notably, the corrosion rate of aluminum alloys was the highest in an environment characterized by a 1:1 water/oil ratio, 0% oxygen, and a temperature of 35 °C. Within this challenging environment, conducive to accelerated corrosion, changes in the corrosion behavior of aluminum alloys over time were analyzed to identify the time point at which MIC intensified. Observations revealed a marked increase in the depth and width of corrosion pits, as well as in the corrosion weight-loss rate, starting from the 7th day. These findings offer valuable insights for determining the optimal frequency of microbial contamination detection in aircraft fuel systems.

Corrosion behavior of X60 pipeline steel in the presence of Sulfate Reducing Bacteria cultured in seawater and mud from the East China Sea

Sulfate-reducing Bacteria (SRB) corrosion is a serious threat to the safety of marine pipelines.To reveal the influence of the corrosion behavior of X60 pipeline steel in the presence of SRB cultured in seawater and mud from the East China Sea The corrosion behavior of X60 pipeline steel was studied with weight loss measurements, microstructure and membrane composition analysis, electrochemical measurements The corrosion rate in sterile seawater is 0.11 mm/y, whereas, in SRB-infested seawater, it increases by 245 % to 0.38 mm/y. In sterile sea mud, the corrosion rate is 0.15 mm/y, but in SRB-infested sea mud, it increases by 87 % to 0.28 mm/y. In the corrosive environment of seawater and mud in the East China Sea, SRB significantly accelerates the microbial corrosion of X60 pipeline steel. These findings provide theoretical guidance for further research on SRB corrosion mechanisms and corrosion control of marine pipelines.

Localized corrosion and brittle fracture of X80 carbon steel under tensile stress induced by sulfate reducing bacteria

The microbiologically influenced corrosion (MIC) of X80 carbon steel under varying tensile stresses with the presence of sulfate reducing bacteria (SRB) was investigated. The stress loads affected the SRB sessile cell counts on the carbon steel, and exerted a significant influence on the rate of MIC to which the carbon steel was subjected. Stresses below 400 MPa elicited a modest promotion effect, whereas the stress of 550 MPa which was approaching the yield strength markedly expedited the corrosion of SRB on X80 carbon steel. Finite element simulation revealed that the elastic stress of 550 MPa led to plastic deformation in the stress concentration zone at the base of the corrosion pit, exacerbating the dissolution of the metal in pits and inducing secondary pitting corrosion. Additionally, this work confirmed that SRB promoted the permeation of hydrogen into the carbon steel matrix. The coexistence of high elastic stress and SRB rendered X80 carbon steel more prone to brittle fracture.

Bacterial adhesion and corrosion behavior of different pure metals induced by sulfate reducing bacteria

The corrosion behaviors of four pure metals (Fe, Ni, Mo and Cr) in the presence of sulfate reducing bacteria (SRB) were investigated in enriched artificial seawater (EASW) after 14-day incubation. Metal Fe and metal Ni experienced weight losses of 1.96 mg cm−2 and 1.26 mg cm−2, respectively. In contrast, metal Mo and metal Cr exhibited minimal weight losses, with values of only 0.05 mg cm−2 and 0.03 mg cm−2, respectively. In comparison to Mo (2.2 × 106 cells cm−2) or Cr (1.4 × 106 cells cm−2) surface, the sessile cell counts on Fe (4.0 × 107 cells cm−2) or Ni (3.1 × 107 cells cm−2) surface was higher.

Occurrence of sulfate-reducing bacteria in well water: identification of anaerobic sulfidogenic bacterial enrichment cultures.

Bacteriological studies of well water mainly focus on aerobic and facultative aerobic coliform bacteria. However, the presence of obligate anaerobic bacteria in well water, especially sulfate-reducing bacteria (SRB), possible causative agents of some diseases, is often ignored. In this study, the presence of SRB and coexisting anaerobic bacteria with SRB in sulfate-reducing enrichment cultures obtained from 10 well water samples in Istanbul was investigated. A nested polymerase chain reaction-denaturing gradient gel electrophoresis strategy was performed to characterize the bacterial community structure of the enrichments. The most probable number method was used to determine SRB number. Out of 10, SRB growth was observed in only one (10%) enrichment culture and the SRB number was low (<10 cells/mL). Community members were identified as Desulfolutivibrio sulfodismutans and Anaerosinus sp. The results show that SRB coexist with Anaerosinus sp., and this may indicate poor water quality, posing a risk to public health. Furthermore, Anaerosinus sp., found in the human intestinal tract, may be used as an alternative anaerobic fecal indicator. It is worth noting that the detection of bacteria using molecular analyzes following enrichment culture techniques can bring new perspectives to determine the possible origin and presence of alternative microbial indicators in aquatic environments.

Synergistic addition of Cu and Ce enhanced sulfate reducing bacteria-assisted corrosion cracking resistance of 2205 duplex stainless steel

The corrosion behaviors of 2205, 2205-Cu, and 2205-Cu-Ce duplex stainless steels (DSSs) were studied under static load in the presence of sulfate-reducing bacteria (SRB). The results demonstrated that the addition of Cu and Ce effectively enhanced the resistance of 2205 DSS to SRB-assisted cracking, and 2205-Cu-Ce DSS exhibited the best corrosion resistance and mechanical properties. The Synergistic addition of Cu and Ce not only inhibited the formation of SRB biofilm but also enhanced the hydrogen-induced cracking resistance of DSSs due to the hydrogen trapping by Cu-rich precipitates.

Effect of Sulphate-Reducing Bacteria Activity on the Performance of Thermally Sprayed Aluminium and Polyurethane Coatings

In the present work, we studied whether the exposure of synthetic seawater with anaerobic sulphate-reducing bacteria (SRB) on some steel samples generates a bacterial biofilm in their surfaces. Bare steel belonging to a mooring chain as well as two coating systems applied on the steel surface were studied: polyurethane (PU) and thermally sprayed aluminium (TSA) with and without an epoxy-based sealant. After 30 days of immersion in SRB-inoculated synthetic seawater, a bacterial count was attained, and the samples were observed using scanning electron microscopy (SEM) and locally analysed using X-ray scattered energy spectroscopy (EDS). A biofilm developed on every tested surface (continuous or in the form of pustules), with evidence of metabolic activity of the SRB. Finally, a mechanism of degradation for TSA in the presence of SRB is proposed for environments with a high concentration of bacteria.

Antibacterial and anticorrosion effects of Cetylpyridinium Chloride against Desulfovibrio desulfuricans biofilm and X80 steel corrosion

In this work, corrosion inhibition of X80 steel caused by Cetylpyridinium Chloride (CPC) in the presence of sulfate-reducing bacteria (SRB) was studied. The results showed that SRB accelerated the steel corrosion, whereas CPC had a good antibacterial activity against SRB corrosion. The growth of SRB was significantly inhibited with CPC concentration 10 mg L–1. The addition of 80 mg L–1 reduced the corrosion rate by 80 % in the presence of SRB. Molecular dynamics simulation and adsorption isotherm calculation showed that CPC can be adsorbed on the steel surface to form a protective film to protect steel form corrosion.

Corrosion of Q235 carbon steel induced by sulfate-reducing bacteria in groundwater: corrosion behavior, corrosion product, and microbial community structure.

Microbiologically influenced corrosion (MIC) is one of the reasons leading to the service failure of pipelines buried in the soil. In this work, the effect of sulfate-reducing bacteria (SRB) on the corrosion behavior of Q235 carbon steel in groundwater was investigated by electrochemical methods, surface analysis, and biological analysis. The results show that SRB utilizes iron as electron donor to sustain the vital activities of organic carbon-starved groundwater during the 14-day experimental period. The microbial community composition analysis at the genus level demonstrate that the diversity and richness decrease after corrosion, and the dominant SRB species has changed from Desulfovibrio to Desulfosporosinus. Moreover, the impedance of the carbon steel in the presence of biofilm was 1 order of magnitude higher than that of other periods in the electrochemical test, indicating that the biofilm and formed ferrous sulfide layer impeded the occurrence of corrosion. Although the 3D topography indicated that the surface of carbon steel was more uneven and pits were increased in the presence of SRB, the average weight loss (0.0396 ± 0.0050 g) was much higher than that without SRB (0.0139 ± 0.0007 g). These results implied that the growth of SRB makes the corrosion process of Q235 carbon steel more complicated.

Effect of Acetate on Microbiologically Influenced Corrosion of Internal Pipeline Surfaces

Microbiologically influenced corrosion (MIC) is a serious threat to the integrity of crude oil pipelines. Sulphate-reducing bacteria (SRB) are the primary microorganisms responsible for MIC, and their aggressiveness is dependent on the energy source available to them. Acetate, a common energy source, has been shown to accelerate the corrosion of carbon steel in the presence of SRB. This study investigated the effect of acetate on the growth of SRB and the corrosion of carbon steel plates in simulated anaerobic conditions. The corrosion kinetics were studied using linear polarization resistance (LPR) and weight loss immersion tests for 42 days. The samples were characterized using Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDX). The results show that the addition of acetate to cultured media significantly increased the corrosion rate of carbon steel plates in both formation water and Postgate Medium B (PMB). This was due to increased growth of SRB in the presence of acetate, which led to the production of more corrosive hydrogen sulphide (H2S). The findings based on experimental data obtained from this study confirm that acetate can accelerate the corrosion of carbon steel in the presence of SRB.

Enhanced Biogenic Sulfidation of Zero-Valent Iron in Columns: Implications for Promoting Dechlorination in Permeable Reactive Barriers.

Biogenic sulfidation of zero-valent iron (ZVI) using sulfate reducing bacteria (SRB) has shown enhanced dechlorination rates comparable to those produced by chemical sulfidation. However, controlling and sustaining biogenic sulfidation to enhance in situ dechlorination are poorly understood. Detailed interactions between SRB and ZVI were examined for 4 months in column experiments under enhanced biogenic sulfidation conditions. SRB proliferation and changes in ZVI surface properties were characterized along the flow paths. The results show that ZVI can stimulate SRB activity by removing excessive free sulfide (S2-), in addition to lowering reduction potential. ZVI also hinders downgradient movement of SRB via electrostatic repulsion, restricting SRB presence near the upgradient interface. Dissolved organic carbon (e.g., >2.2 mM) was essential for intense biogenic sulfidation in ZVI columns. The presence of SRB in the upgradient zone appeared to promote the formation of iron polysulfides. Biogenic FeSx deposition increased the S content on ZVI surfaces ∼3-fold, corresponding to 3-fold and 2-fold improvements in the trichloroethylene degradation rate and electron efficiency in batch tests. Elucidation of SRB and ZVI interactions enhances sustained sulfidation in ZVI permeable reactive barrier.

Corrosion behavior and mechanism of N80 steel caused by sulfate reducing bacteria in CO2-saturated shale gas field produced water at 60 ℃

The corrosion of steel caused by sulfate reducing bacteria (SRB) in shale gas environment is one of the big factors leading to the severe failure of pipeline steel. However, the related studies of SRB corrosion especially at a high temperature are still poor. This paper aims to investigate the effects of SRB on the corrosion behavior of N80 steel in CO2-saturated simulated shale gas produced water at 60 °C by weight loss, 3D microscope,electrochemical impedance spectroscopy (EIS) and polarization curves and so on. Results showed that the corrosion rate of N80 steel in the presence of SRB was greater than that of the abiotic control specimen. SRB cells and the inhibitive organics could have a competitive adsorption on the steel surface. The adsorption of inhibitive organics on steel in the abiotic condition caused a slight corrosion of the control specimen. While the adsorption of SRB cells as well as the subsequent formation of biofilm have accelerated the localized corrosion of specimen. Therefore, steel corrosion is accelerated in the presence of SRB at a high temperature.

Corrosion Mechanism of Typical Shale Gas Gathering and Transportation Pipelines in Southwest China

The shale gas surface gathering and transportation pipeline in southwest China has experienced serious internal corrosion, which affects the production of shale gas wells and has great potential safety hazards. To find out the corrosion type and corrosion mechanism, the corrosion analysis and mechanism research of gathering and transportation pipelines are carried out, including corrosion morphology observation, corrosion product analysis, fluid mechanics calculation, etc. The results show that the corrosion products of the gathering and transportation pipeline are mainly FeCO3 with high S content, and the corrosion type is sulfate-reducing bacteria (SRB) and CO2 corrosion. At the same time, the corrosion pits are mainly distributed on the approach stream side, which is closely related to the scouring effect of the medium flow in the vertical branch pipe on the wall surface of the tee. The corrosion weight loss test shows that the corrosion rate of sterile solution is significantly lower than that of bacterium solution, indicating that the presence of SRB significantly expedites the corrosion of materials.

Stress Corrosion Behaviour of a Heating Ageing-treated Al- 4.47Zn-2.13Mg-1.20Cu Alloy in the Presence of Sulfate Reducing Bacteria

Stress Corrosion Behaviour of a Heating Ageing-treated Al- 4.47Zn-2.13Mg-1.20Cu Alloy in the Presence of Sulfate Reducing Bacteria

Corrosion Behavior of L360N Steel in the Presence of Sulfate-Reducing Bacteria under Three Cathodic Potentials

Corrosion Behavior of L360N Steel in the Presence of Sulfate-Reducing Bacteria under Three Cathodic Potentials

Role of Sulfate-Reducing Bacteria in the Removal of Hexavalent Chromium by Biosynthetic Iron Sulfides (FeS1+x)

The reduction of Cr(VI) by biosynthesis iron sulfides (FeS1+x) under anoxic conditions has been studied extensively. However, the role of sulfate-reducing bacteria (SRB) when FeS1+x containing SRB removes contaminants during in situ remediation still needs further study. The secondary kinetic constant of biosynthetic FeS1+x with the presence of SRB (called BS-FeS1+x) was 1.72 times that of FeS1+x with the absence of SRB (called BNS-FeS1+x) under FeS1+x:Cr(VI) molar ratio = 10:1, indicating that SRB had a promoting effect on the removal of Cr(VI). Additionally, XPS showed that 5.7% of Cr(VI) remained in the solid phase in the BS-FeS1+x system, indicating BS-FeS1+x could not only remove Cr(VI) by reduction but also by adsorption. Meanwhile, the Cr(VI) removal efficiency of BS-FeS1+x was 100% under anoxic conditions with FeS1+x:Cr(VI) molar ratio = 1:1, which was higher than BNS-SRB (93.4%). SRB could enhance the Cr(VI) removal efficiency, which was possibly due to the constant release of S(-II) and the improvement of the stability and dispersion and the buffering effect. This discovery provided an inspiring idea of the application of biosynthetic iron sulfides to in situ remediation.

Corrosion Behavior on 20# Pipeline Steel by Sulfate-Reducing Bacteria in Simulated NaCl Alkali/Surfactant/Polymer Produced Solution.

The corrosion behavior of sulfate-reducing bacteria (SRB) on 20# carbon steel in the NaCl alkali-surfactant-polymer (ASP) flooding system was studied by scanning electron microscopy, electrochemical measurement, X-ray photoelectron spectroscopy, and laser confocal microscopy. The results showed that the presence of SRB results in a large viscosity loss of the system. SRB can use hydrolyzed polyacrylamide (HPAM) as a nutrient to grow, and the number of SRB remained at a high level after 15 days. Weight loss and electrochemical tests indicated that SRB promoted corrosion of pipeline steel. The corrosion of carbon steel in the early stage of immersion was inhibited by the biofilm formed on the surface, and the thick biofilm in the later stage of immersion caused serious pitting corrosion. The localized corrosion caused by SRB was not inhibited by HPAM and sodium petroleum sulfonate (surfactant) adsorbed on the surface.

Selective corrosion behavior of X80 steel heat affected zone by SRB in coastal saline soil

The corrosion behavior of heat affected zone of X80 pipeline steel was investigated in coastal saline soil with or without sulfate-reducing bacteria (SRB). In the sterile soil environment, the diameter, depth, and density of corrosion pits detected in the coarse grain zone (CGZ) were larger than those in the fine-grained zone (FGZ) and fusion zone (FZ). In the soil environment inoculated with SRB, the microbes enhance the corrosion of FGZ, CGZ, and FZ. The corrosion susceptibility of CGZ coupons is stronger in the presence of SRB than those of FGZ and FZ coupons.

Effect of alloying element content on anaerobic microbiologically influenced corrosion sensitivity of stainless steels in enriched artificial seawater

Stainless steels (SS) are not immune to microbiologically influenced corrosion (MIC) especially in the presence of sulfate reducing bacteria (SRB). It is necessary to study the influence of alloying elements on the MIC. SRB MIC behaviors of four stainless steels (2205 SS, 316L SS, 304 SS, and 410 SS), with different alloying element compositions were compared after 14 days of incubation at 37°C in enriched artificial seawater inoculated with Desulfovibrio sp. The sessile cell sequence was 410 SS > 316L SS > 304 SS > 2205 SS, inversely proportional to Cr content. The uniform corrosion rate (based on weight loss) sequence was 410 SS > 304 SS > 316L SS > 2205 SS, which matches the pitting resistance equivalent number (PREN) sequence inversely. 410 SS with the lowest Cr and Mo contents suffered the most severe pitting, with pit depth of 35 μm and weight loss of 0.75 mg/cm2 (0.91 mm/a pitting rate and 25 μm/a uniform corrosion rate). The other three stainless steels with higher Cr and Mo contents suffered only metastable pits. The semiconductor characteristics and the re-passivation abilities of the passive films were found to be affected by Cr and Mo contents.

Investigating inhibition characteristics of Butea monosperma leaf extracts to retard stainless steel biocorrosion in the presence of sulfate-reducing bacteria

The influence of sulfate-reducing bacteria Desulfovibrio desulfuricans on stainless steel SS 202 corrosion in neutral media was studied in detail using weight loss and electrochemical routes. The bacterial activity resulted in material loss with an average rate of 0.015 mm/year. The scanning electron microscopy (SEM) analysis showed a significant increase in the sessile bacterial population with the immersion period. Use of 500 ppm palash (Butea monosperma) leaf extract (PLE) reduced the average corrosion rate to 0.002 mm/year. SEM analysis showed a very thin external film formation in the presence of the inhibitor. The X-ray photoelectron spectroscopy studies confirmed the presence of corrosion products such as Fe2O3 and FeS. The gas chromatography?mass spectrometry studies showed the dominant percentage of various terpenoids along with vitamin E as the main components of the PLE. Electrochemical analysis showed the existence of a diffusion barrier. The resistance offered by the diffusion barrier is high in the inhibited sample when compared to uninhibited samples.