Capacitive deionization (CDI) has been investigated for brackish water desalination, selective removal of ions, and water softening. We used humic acid (HA) and alginate sodium (SA) to simulate different kinds of natural organic matter to investigate the fouling phenomena during CDI operation. Adsorption amount and energy efficiency were studied. Results showed that both SA and HA could decrease the removal of NaCl during CDI operation. There existed a slight decrease of energy consumption in SA solutions which was opposite to that in HA solutions. HA can compete with ions adsorbed by electrodes and attach to electrodes adhesively, resulting in co-ion repulsion. SA is not sensitive to electrical field and its fouling is not obvious. The amount of adsorbed Mg²⁺ would increase from 0.927 mg/g to 1.508 mg/g in ten cycles' operation and the increment of Ca²⁺ was from 1.885 mg/g to 2.878 mg/g in SA solutions. This increase of adsorption was due to the complexation between SA and cations. Simultaneously, energy consumption was decreased. In HA solutions, energy consumption of Mg²⁺ and Ca²⁺ adsorption increased. In ten cycles' operations, both HA and SA could reduce the efficiency of CDI operation. The types of organic substances are important factors in fouling of CDI electrodes.

电容去离子 (CDI) 已被研究用于微咸水淡化、选择性去除离子和软化水。我们使用腐殖酸 (HA) 和海藻酸钠 (SA) 来模拟不同种类的天然有机物，以研究 CDI 操作过程中的结垢现象。研究了吸附量和能量效率。结果表明，SA和HA都可以减少CDI操作过程中NaCl的去除。SA 解决方案的能耗略有下降，这与 HA 解决方案相反。HA 可以与电极吸附的离子竞争并粘附在电极上，导致共离子排斥。SA对电场不敏感，污垢不明显。Mg ²⁺吸附量在 10 个循环的操作中，Ca ²⁺从 0.927 mg/g 增加到 1.508 mg/g，并且在 SA 溶液中 Ca ²⁺的增量从 1.885 mg/g 增加到 2.878 mg/g。这种吸附的增加是由于 SA 和阳离子之间的络合。同时，能耗降低。在HA溶液中，Mg ²⁺和Ca ²⁺吸附的能耗增加。在 10 个周期的操作中，HA 和 SA 都会降低 CDI 操作的效率。有机物的种类是导致 CDI 电极结垢的重要因素。