Microbiologically influenced corrosion(MIC) is a big threat to the strength and safety of many metallic materials used in different environments throughout the world. The metabolites and bioactivity of the microorgani...Microbiologically influenced corrosion(MIC) is a big threat to the strength and safety of many metallic materials used in different environments throughout the world. The metabolites and bioactivity of the microorganisms cause severe deterioration on the metals. In this study, MIC of pure titanium(Ti) was studied in the presence of a highly corrosive aerobic marine bacterium Pseudomonas aeruginosa. The results obtained from electrochemical test showed that Ti was corrosion resistant in the abiotic culture medium after 14 d, while the increased corrosion current density(i_(corr)) obtained from polarization curves and the decreased charge transfer resistance(R_(ct)) from electrochemical impedance spectroscopy(EIS)indicated the accelerated corrosion of Ti caused by P. aeruginosa biofilm. For further confirmation of the above results, the surface of Ti was investigated using scanning electron microscopy(SEM), confocal laser scanning microscopy(CLSM) and X-ray photoelectron spectroscopy(XPS). According to the XPS results, TiO_2 was formed in both abiotic and biotic conditions, while unstable oxide Ti_2O_3 was detected in the presence of P. aeruginosa, leading to the defects in the passive film and localized corrosion. Pitting corrosion was investigated with the help of CLSM, and the largest pit depth found on Ti surface immersed in P. aeruginosa was 1.2 μm. Ti was not immune to MIC caused by P. aeruginosa.展开更多
In the present study, a novel bacterium( Marinobacter aquaeolei) was examined for its corrosion inhibiting behaviour against X80 pipeline steel. Electrochemical results showed that X80 steel immersed in the solution i...In the present study, a novel bacterium( Marinobacter aquaeolei) was examined for its corrosion inhibiting behaviour against X80 pipeline steel. Electrochemical results showed that X80 steel immersed in the solution inoculated with M. aquaeolei possessed very high corrosion resistance compared to that of abiotic control. Besides, scanning electron microscopy, confocal laser scanning microscopy and energy-dispersive X-ray spectroscopy were employed to analyse the corrosion product and the biofi lm formed on the metal surface. Fourier-transform infrared spectroscopy was also applied to determine the composition of extracellular polymeric substances(EPS). Above results indicated that the corrosion inhibition effciency observed in biotic medium was very high(91%), proving that M. aquaeolei was an effective inhibitive agent for the corrosion of carbon steel. The inhibition was credited to the formation of bacterial biofi lm and the compact protective layer of the secreted EPS. Thus, this study will introduce a natural, environmentally friendly and cost-effective system for the corrosion control of the carbon steel.展开更多
Stainless steel(SS)has unsatisfied corrosion resistance in many aggressive environments,particularly under a low p H condition in the bioleaching industry.In this study,through surface analyses and electrochemical mea...Stainless steel(SS)has unsatisfied corrosion resistance in many aggressive environments,particularly under a low p H condition in the bioleaching industry.In this study,through surface analyses and electrochemical measurements,the corrosion resistance of a novel Cu-bearing 316L SS was evaluated in the presence of an acid-producing bacterium,Acidithiobacillus caldus SM-1 that was able to create an extremely acidic corrosive environment.The significantly enhanced anti-microbiologically-inducedcorrosion performance could be explained by the intracellular reactive oxygen species(ROS)and Fenton reaction on the Cu-bearing 316L SS.展开更多
基金supportedfinancially by the National Natural Science Foundation of China(No.U1660118)the National Basic Research Program of China(No.2014CB643300)the National Environmental Corrosion Platform(NECP)
文摘Microbiologically influenced corrosion(MIC) is a big threat to the strength and safety of many metallic materials used in different environments throughout the world. The metabolites and bioactivity of the microorganisms cause severe deterioration on the metals. In this study, MIC of pure titanium(Ti) was studied in the presence of a highly corrosive aerobic marine bacterium Pseudomonas aeruginosa. The results obtained from electrochemical test showed that Ti was corrosion resistant in the abiotic culture medium after 14 d, while the increased corrosion current density(i_(corr)) obtained from polarization curves and the decreased charge transfer resistance(R_(ct)) from electrochemical impedance spectroscopy(EIS)indicated the accelerated corrosion of Ti caused by P. aeruginosa biofilm. For further confirmation of the above results, the surface of Ti was investigated using scanning electron microscopy(SEM), confocal laser scanning microscopy(CLSM) and X-ray photoelectron spectroscopy(XPS). According to the XPS results, TiO_2 was formed in both abiotic and biotic conditions, while unstable oxide Ti_2O_3 was detected in the presence of P. aeruginosa, leading to the defects in the passive film and localized corrosion. Pitting corrosion was investigated with the help of CLSM, and the largest pit depth found on Ti surface immersed in P. aeruginosa was 1.2 μm. Ti was not immune to MIC caused by P. aeruginosa.
基金Financial support was provided by the Shenzhen Science and Technology Research Funding (Grant No. JCY20160608153641020)the National Natural Science Foundation of China (Grant Nos. 51771199 and 51501188)+1 种基金the National Basic Research Program of China (Grant No. 2016YFB0300205)the State Key Program of National Natural Science of China (Grant No. 51631009)
文摘In the present study, a novel bacterium( Marinobacter aquaeolei) was examined for its corrosion inhibiting behaviour against X80 pipeline steel. Electrochemical results showed that X80 steel immersed in the solution inoculated with M. aquaeolei possessed very high corrosion resistance compared to that of abiotic control. Besides, scanning electron microscopy, confocal laser scanning microscopy and energy-dispersive X-ray spectroscopy were employed to analyse the corrosion product and the biofi lm formed on the metal surface. Fourier-transform infrared spectroscopy was also applied to determine the composition of extracellular polymeric substances(EPS). Above results indicated that the corrosion inhibition effciency observed in biotic medium was very high(91%), proving that M. aquaeolei was an effective inhibitive agent for the corrosion of carbon steel. The inhibition was credited to the formation of bacterial biofi lm and the compact protective layer of the secreted EPS. Thus, this study will introduce a natural, environmentally friendly and cost-effective system for the corrosion control of the carbon steel.
基金financially supported by the National Natural Science Foundation of China(Nos.51871050 and U1660118)the Fundamental Research Funds for the Central Universities(Nos.N180205021,N180203019,and N2002019)the Liaoning Revitalization Talents Program(No.XLYC1907158)。
文摘Stainless steel(SS)has unsatisfied corrosion resistance in many aggressive environments,particularly under a low p H condition in the bioleaching industry.In this study,through surface analyses and electrochemical measurements,the corrosion resistance of a novel Cu-bearing 316L SS was evaluated in the presence of an acid-producing bacterium,Acidithiobacillus caldus SM-1 that was able to create an extremely acidic corrosive environment.The significantly enhanced anti-microbiologically-inducedcorrosion performance could be explained by the intracellular reactive oxygen species(ROS)and Fenton reaction on the Cu-bearing 316L SS.
