直饮水系统环境中铜管水垢沉积问题研究

在直饮水系统环境中使用电化学方法在铜管表面加速沉积了一层碳酸钙水垢,结合计时电流法、扫描电子显微镜(SEM)和电化学阻抗谱(EIS)研究了Ca2+离子浓度、表面粗糙度和沉积时间对水垢沉积速率、成核机理、形貌结构、耐蚀性能的影响。结果表明:Ca2+浓度越高,沉积速率越快,碳酸钙构型逐渐由方解石变为球文石。表面粗糙度越大,沉积时间越短且晶体的不均匀性增加,抛光处理的铜具有明显的连续成核机制。随着沉积时间的增加,表面逐渐被水垢层完全覆盖,电化学阻抗测试表明铜管的耐蚀性能先下降后上升。

Research on problem of scale deposition of Cu pipe in environment of direct drinking water system

A layer of calcium carbonate incrustation was deposited on Cu pipe accelerated by electrochemical method in direct drinking water system environment. Combined with chronoamperometry, scanning electron microscope (SEM) and electrochemical impedance spectroscopy (EIS),the paper researched the effects of Ca²⁺ concentration, surface roughness and deposition time on deposition rate, nucleation mechanism, morphology structure and corrosion resistance. The results showed that the higher the Ca²⁺ concentration, the sooner the deposition rate, the structure of calcium carbonate is gradually changed from calcite to vaterite. The deposition time shortened and crystal inhomogeneity increased with the increase of surface roughness. The polished Cu has obvious and progressive nucleation mechanism.The surface is gradually all covered by scale with the increase of deposition time.The electrochemical impedance test indicated that the corrosion resistance of Cu pipe decrease first and increase later.