摘要：

为掌握电去离子（EDI）膜块内离子交换树脂层态分布规律，首先分析了EDI离子交换树脂迁移失效层、交换稳定层和水解保护层的工作原理和特点，随后通过实验测试了进水电导率和运行电流对离子交换树脂层态分布的影响。结果表明，水解保护层厚度与进水电导率负相关，与运行电流正相关，水解保护层是保证EDI膜块产水水质的关键点。在进水电导率≤10 µS/cm（25 ℃）时，水解保护层厚度占整个树脂层厚度的比例≥11.43%，可以很好地保证EDI膜块产水电导率<0.1 µS/cm（25 ℃）。在进水电导率为5 µS/cm、产品水电导率<0.1 µS/cm（25 ℃）时，提高运行电流可以增大水解保护层厚度，且水解保护层厚度与运行电流成线性关系。

关键词: 电去离子技术, 膜块, 离子交换树脂, 层态分布, 水解保护层

Abstract:

In order to master the distribution law of each layer state of the ion exchange resin in the EDI membrane block, this paper firstly analyzed the working principles and characteristics of the migration failure layer, exchange stability layer and hydrolysis protection layer of EDI ion exchange resin. Then, the effects of influent conductivity and operating current on the layer state distribution were tested through experiments. The results showed that the thickness of the hydrolytic protection layer was negatively correlated with the influent conductivity and positively correlated with the operating current. The hydrolysis protection layer was the key point to ensure the quality of product water from EDI membrane block. When the influent conductivity was less than 10 µS/cm (25 ℃), the ratio of the hydrolytic protective layer thickness to the thickness of the whole resin layer was ≥11.43%, which could well ensure that the conductivity of product water from EDI membrane block was <0.1 µS/cm (25 ℃). When the conductivity of influent was 5 µS/cm and the conductivity of product water was <0.1 µS/cm (25 ℃), the thickness of the hydrolytic protective layer could be increased by increasing the operating current, and the thickness of the hydrolytic protective layer was linear with the operating current.

Key words: EDI, membrane blocks, ion exchange resin, layer state distribution, hydrolysis protection layer

中图分类号: 

• TQ085

• TU991.26