钙离子浓度对铜材硫酸盐还原菌腐蚀的影响

Effect of Concentration of Calcium Ions on Corrosion Behav-ior of Copper in the Presence of Sulfate-Reducing Bacteria

微生物对铜材及其合金有腐蚀,硫酸还原菌是引起微生物腐蚀的菌种之一,过去对此研究不够。采用极化曲线和电化学交流阻抗谱技术考察了在0,200,500,800mg/LCa2+培养基中培养2,3,4,5,6d后的硫酸盐还原菌菌液对铜材的腐蚀作用。结果表明:在200mg/LCa2+培养基中培养6d后硫酸盐还原菌菌液对铜电极的腐蚀作用最弱,Ca2+浓度继续增加,铜电极腐蚀加速;0,200mg/LCa2+菌液培养的前3d对铜电极有较明显的腐蚀作用,而后期则对铜电极有缓蚀作用;Ca2+浓度继续增加,在培养的6d内均不同程度地加剧铜电极的腐蚀。

Sulfate-reducing bacteria solu-tions were cultivated from solutions with different concentrations of Ca2+ (0, 200, 500, 800 mg/L) for different durations (1,2, 3, 4, 5 ,6 d). The effect of the resulting bacteria solutions on the corrosion behavior of copper was investigated by measuring poten-tiodynamic polarization curves and electrochemical impedance spectra. Results show that the sulfate-reducing bacteria solution cultivated in the solution containing 200 mg/L Ca2+ for 6 d has the best inhibition effect for Cu electrode, and corrosion of the Cu electrode is accelerated with increasing concentration of Ca2+ . After being cultivated for 3 d in the solution containing 0 mg/L and 200 mg/L Ca2+ , the resulting bacteria solutions accelerated the corrosion of copper, but those bacteria solutions cultivated in the follow-up days had significant corrosion inhibition effect for the Cu electrode. Besides, the bacteria solutions cultivated for 6 d in the solutions with high concentration of Ca2+ (above 200 mg/L) always accelerated the corrosion of the Cu electrode.