为给磷酸三钠的应用提供指导,系统研究了磷酸三钠缓蚀性能的影响因素。采用静态失重法、动电位极化曲线法和电化学交流阻抗法,评价了磷酸三钠对某一联合站污水的缓蚀效果,并研究了污水介质中钙镁离子含量、含氧量和温度对其缓蚀性能的影响。结果表明,磷酸三钠作为一种阳极型缓蚀剂,当其质量浓度大于25 mg/L时才有明显的缓蚀效果,在应用过程中必须注意使用浓度要高于最低有效浓度。并且钙镁离子的存在和温度的升高会抑制磷酸三钠的缓蚀效果,而适当的氧气含量可促进钢铁表面氧化膜的形成,进一步促进缓蚀作用。此外现场实践表明,磷酸三钠作为一种廉价的缓蚀剂具有良好的应用效果。

In order to provide advice for the application of trisodium phosphate,the influencing factors of its corrosion inhibition performance were systematically studied.The corrosion inhibition effect of trisodium phosphate on the wastewater of a certain combined station was evaluated by static weight loss method,polarization curves and electrochemical impedance spectroscopy.The influence of other factors including calcium and magnesium ions concentration,oxygen content and temperature of the sewage medium on its corrosion inhibition performance was also estimated.Results showed that trisodium phosphate as an anodic corrosion inhibitor had obvious corrosion inhibition effect only when its mass concentration was greater than 25 mg/L. It must be noted that the application concentration should be higher than the minimum effective concentration.Moreover,the presence of calcium and magnesium ions as well as the increase of temperature would inhibit the corrosion inhibition effect of trisodium phosphate,while the appropriate oxygen content could promote the formation of oxide film on the steel surface and further promote the corrosion inhibition.In addition,field practice showed that trisodium phosphate had a good application effect as an inexpensive corrosion inhibitor.