摘要
目的揭示培养周期内脱硫弧菌(一种硫酸盐还原菌)引起的铝的微生物腐蚀机理。方法采用细胞计数、荧光显微镜、电子显微镜、X射线能谱仪以及电化学测试等技术,测试并分析铝在硫酸盐还原菌(SRB)培养基中的腐蚀行为和机理。结果培养初期,SRB没有引起铝的腐蚀速率加速。铝电极的线性极化电阻在SRB培养基中的值甚至高于无菌培养基。这是因为生物膜的累积阻碍了基体与溶液介质界面的电子传输。随着培养时间的延长,铝在SRB培养基中的腐蚀速率明显提高。培养7天时,铝电极在SRB培养基中的腐蚀电流比无菌培养基中高3个数量级。结论随着时间的延长,培养基中有机碳源等营养成分消耗过多,导致SRB无法从培养基中获得足够的营养源,进而转向从铝中获取自身呼吸作用所需的能量。同时,由于生物膜的覆盖导致膜下微环境的改变,局部酸性可能较大,进而加速了点蚀的形成。
This paper aims to reveal the microbiologically influenced corrosion mechanism of aluminum caused by Desulfovibrio(a sulfate reducing bacteria)during an incubation period.Cell counting,fluorescence microscopy,electron microscopy,X-ray spectrometer,and electrochemical testing were used to test and analyze the corrosion behavior and corrosion mechanism of aluminum in sulfate reducing bacteria(SRB)culture medium.Results showed that SRB did not accelerate the corrosion rate of aluminum at the initial incubation period.The linear polarization resistance of the aluminum in the SRB culture medium was even higher than that in the abiotic medium,which was because the accumulation of biofilm hindered the electron transportation at the interface between the metal substrate and the solution medium.With the increase of cultivate time,the corrosion rate of aluminum in SRB culture medium accelerated significantly.When cultivated for 7 days,the corrosion current of aluminum in SRB culture medium was 3 orders of magnitude higher than that in abiotic medium.With the excessive consumption of organic carbon source and other nutrients over time,the culture medium is not enough to support the growth of SRB,which caused the SRB to obtain the energy from the aluminum to maintain its metabolism.At the same time,the local acidity of the substrate may be aggravated due to the change of the microenvironment caused by the coverage of the biofilm,which accelerates the formation of pitting corrosion.
作者
韩晓梅
窦雯雯
蒲亚男
全雨
宋翼
陈守刚
HAN Xiao-mei;DOU Wen-wen;PU Ya-nan;QUAN Yu;SONG Yi;CHEN Shou-gang(School of Materials Science and Engineering,Ocean University of China,Qingdao 266100,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2020年第7期255-262,共8页
Surface Technology
基金
国家自然科学基金(51572249,U1806223)
山东省腐蚀科学重点实验室开放课题(KLCS201903)
中国博士后科学基金(2018M640655,2019T120610)。
关键词
纯铝
生物膜
SRB
有机碳源
微生物腐蚀
bare aluminum
biofilm
SRB
organic carbon sources
microbiologically influenced corrosion
