摘要
应用丝束电极研究了半连续培养基中SRB及其生物膜对Q2 35低碳钢腐蚀的影响 .采用电位、电流以及阻抗扫描技术测试了生物膜的不均匀性特性 ,以及电极开路电位和电化学阻抗谱 (EIS)与培养时间的关系 .发现随生物膜的成长 ,开路电位负移 .由于生物膜中SRB代谢产生的硫化物具有导电性 ,使表面电位扫描已不能作为生物膜下局部腐蚀的判据 ,但表面阻抗扫描却可探测到膜下的局部腐蚀 .EIS表明 ,生物膜电容极大 (10 4 ～ 10 5μF/cm2 ) ,且膜电容随时间呈S型增加 ,而溶液电阻和电荷传递电阻则呈指数下降 .
Wire beam electrode(WBE) was applied to study the microbiologically influenced corrosion(MIC) of Q235 carbon steel associated with sulphate reducing bacteria(SRB) in semicontinuous culture medium(to be completely refreshed every 72 hours).The potential,galvanic current density and impedance mapping,as well as open circuit potential(OCP) and electrochemical impedance spectrum(EIS) were measured to predict the localized corrosion under biofilm during SRB growing.As a result,the OCP moved negatively gradually with time.However,The mapping showed the potential fluctuation on the WBE surface decreased over time due to the conductivity of FeS x ( x =0.9～2) metabolized by SRB in the biofilm.Therefore,the potential mapping could not be a criterion of localized corrosion under biofilm.Instead,the impedance mapping could give a good prediction to the MIC.In addition,The biofilm capacity moved up to a very large level(～10 5 μF/cm 2) in shape of sigmoid when SRB grew.At the same time,both solution resistance and charge transfer resistance decreased exponentially.
出处
《中国腐蚀与防护学报》
CAS
CSCD
2002年第1期48-53,共6页
Journal of Chinese Society For Corrosion and Protection
基金
中国石油天然气总公司资助项目 (编号 :10 990 311)
关键词
微生物诱导腐蚀
碳钢
电化学阻抗谱
丝束电极
microbiologically influenced corrosion,carbon steel,electrochemical impedance spectrum
