结合扫描电镜(SEM)及能谱(EDS)分析, 采用电化学阻抗谱、极化曲线测试以及丝束电极(WBE)技术, 对黄铜电极在含硫酸盐还原菌(SRB)的模拟冷却水中表面成膜及腐蚀状况进行了分析。结果表明, 在含菌模拟冷却水溶液中, 电极表面会形成一层生物膜, 电极表面含有铜和硫等元素。电化学测试分析结果显示, 随着浸泡时间延长, 无菌溶液中铜电极的阻抗值不断增大, 腐蚀电流密度下降; 含菌溶液中铜电极的阻抗值则随时间减小, 腐蚀电流密度显著增大; 浸泡初期电极表面的极差较大, 随时间延长极差不断减小, 显示浸泡初期电极表面状态不一致性较大, 可能是浸泡初期SRB在电极表面成膜不均匀, 从而导致局部区域的腐蚀。

The electrochemical corrosion behaviour of brass in simulated cooling water containing sulphate-reducing bacteria was investigated by electrochemical impedance spectroscopy, polarization curve, wire beam electrode measurement, scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). SEM photographs and EDS analysis indicated that a slimy layer or biofilm formed on electrode surface in solution containing SRB, and the elements such as Cu and S were detected. According to the results of electrochemical measurements, the brass electrode impedance increased and the corrosion current density decreased with the immersion time in sterile solution. The impedance of brass electrode decreased and the corrosion current density significantly increased in solution with SRB. The results of wire beam electrode measurement showed that at the initial stage of immersion, the largest potential difference of the electrode surface was relatively high and then decreased with immersion time, indicating electrochemical inconsistency of the surface which may be caused by the uneven biofilm at that stage, and causing corrosion in local region.