Department of Chemical Engineering, Dalian University of Technology, No. 2, Linggong Road, Dalian 116024, China E-mail:
Water Sci Technol. 2021 May;83(10):2549-2559. doi: 10.2166/wst.2021.161.
Electrodeionization (EDI) technology is limited by low regeneration efficiency of ion exchange resins, requirements of high-quality influent water, fouling of the ion exchange membrane and electrode, etc. In this work, a novel bed type called a compound bed in which cation and anion exchange resins were near the cation and anion exchange membrane and placed in layers, was proposed to implement high-efficiency regeneration of ion exchange resins. The influence of different operating conditions on the regeneration efficiency of ion exchange resins was elucidated as well. The regeneration efficiency of ion exchange resins could reach 73.1%, when the device was operated for 5 h under current density of 9 mA/cm, with a cation and anion exchange resins ratio of 2: 3, influent water conductivity of 1,360 μS/cm and hardness of 400 mg/L. Therefore, the proposed compound bed structure not only widened the inlet water conditions, but also achieved the high-efficiency regeneration of ion exchange resins and anti-fouling of membranes and electrodes.
电去离子（EDI）技术受到离子交换树脂再生效率低、进水水质要求高、离子交换膜和电极结垢等因素的限制。在这项工作中，提出了一种新型床层结构，即复合床层，其中阳离子和阴离子交换树脂靠近阳离子和阴离子交换膜，并分层放置，以实现离子交换树脂的高效再生。还研究了不同操作条件对离子交换树脂再生效率的影响。当电流密度为 9 mA/cm，运行 5 h，阳离子和阴离子交换树脂比为 2:3，进水电导率为 1,360 μS/cm，硬度为 400 mg/L 时，离子交换树脂的再生效率可达 73.1%。因此，所提出的复合床层结构不仅拓宽了进水条件，而且实现了离子交换树脂的高效再生以及膜和电极的抗污染。
