关键词: 生物膜, 硫酸盐还原菌, 碳钢, 丝束电极, 面电位/电流分布, 电化学阻抗谱

Abstract: Wire Beam Electrode (WBE) made of Q235 carbon steel was applied to study the heterogeneous corrosion beneath biofilm formed by Sulfate Reducing Bacteria (SRB) in culture and sulfide film in solution with 1% NaCl and 300 mg/L S 2- . The potential,galvanic density mapping,as well as polarization curve and Electrochemical Impedance Spectrum (EIS) were measured to predict the localized corrosion under biofilm and sulfide film.As a result,the mapping showed the potential fluctuation on the WBE surface decreased over time due to the conductivity of the biofilm and sulfide film.Therefore,the potential mapping could not be a criterion of localized corrosion under biofilm.Instead,the current mapping could give a good prediction to the MIC.The sulfide film could inhibit corrosion of carbon steel.However,the biofilm accelerate the corrosion.Polarization resistance R p increased over time in the Na 2S solution if lack of O 2.In addition,the biofilm capacity moved up to a very large level (～10 5 μF/cm 2)in shape of Sigmoid with its polarization resistance decreasing exponentially when SRB grew.