Electrochemical precipitation has attracted widespread attention in the treatment of recirculating cooling water in recent years. In order to guarantee continuous water softening efficiency, periodic scale detachment of cathode is indispensable. Nevertheless, periodic mechanical scrapping, prevalent scale detachment technique currently, increases the interelectrode gap, resulting in the decline of water softening efficiency and the rise of energy consumption. In this paper, polarity reversal was applied in the electrochemical precipitation process for removing scale deposits. The results showed that scale deposits were removed effectively and high water softening efficiency were accomplished steadily. The precipitation rate obtained was 53.9–73.4 g/h/m². The reactor still could remove hardness ions efficiently after the scale detachment by polarity reversal. The energy consumption maintained in the range of 17.3–23.6 kWh/kg CaCO₃. The total hardness removal efficiency was 16.4–21.4%. Repeated experimental results demonstrated that the electrochemical precipitation process adopting polarity reversal for scale detachment could operate steadily without any performance degradation detected. Cyclic voltammetric investigation showed good electrochemical stability of dimensionally stable anode (DSA) used. Accelerated life test indicated that it could keep active steadily in polarity reversal condition.

近年来，电化学沉淀在循环冷却水的处理中引起了广泛的关注。为了保证连续的水软化效率，阴极的周期性水垢分离是必不可少的。然而，目前的定期机械刮擦，普遍的水垢分离技术增加了电极间的间隙，导致水软化效率下降和能量消耗增加。在本文中，极性反转被应用于电化学沉淀过程中以去除水垢沉积物。结果表明，有效去除了水垢沉积物，稳定地实现了高水软化效率。获得的降水量为53.9-73.4 g / h / m ²。通过极性反转使水垢分离后，反应器仍然可以有效地去除硬度离子。能耗保持在17.3–23.6 kWh / kg CaCO ₃的范围内。总硬度去除效率为16.4–21.4％。重复的实验结果表明，采用极性反转进行水垢分离的电化学沉淀过程可以稳定运行，而没有发现任何性能下降。循环伏安研究表明所用尺寸稳定阳极（DSA）具有良好的电化学稳定性。加速寿命试验表明，它在极性反转的情况下可以稳定地保持活动。