Abstract: The traditional demineralized water system is based on the reverse osmosis and mixed ion exchange technology. The process is complicated, the effluent quality is poor, and a large amount of acidic and alkaline wastewater is generated during the regeneration of the mixed bed. The reverse osmosis and EDI (Electrodeionization) system has the advantages of small discharge of process wastewater, simple operation and maintenance, no acidic and alkaline wastewater. The conductivity of the produced water is reduced to below 0.1 μS/cm, and the sodium and silicon ion content is controlled below 10 μg/L, which is an ideal demineralized water system process. The application of EDI in the demineralized water system is introduced in detail. The differences in energy consumption, energy saving and emission reduction, economic benefit and operation before and after the EDI module update are compared and analyzed. Compared with the MK-2 module, the conductivity of produced water is further reduced to below 0.06 μS/cm, and it has outstanding performance in energy saving, emission reduction and economic benefits.

Key words: EDI, demineralized water, mixed ion exchange, water quality, energy saving, economic benefits

摘要： 传统的除盐水系统基于反渗透加混床离子交换工艺,工艺复杂,出水水质较差,且混床再生过程中产生大量的含酸、含碱废水。而反渗透加EDI(连续电除盐技术)系统的工艺废水排放量较少,运行维护简单,不产生含酸、含碱废水,产品水电导率降低至0.10 μS/cm以下,钠、硅离子质量浓度控制在10 μg/L以下,水质明显提升,是理想的除盐水系统工艺。对EDI在除盐水系统中的应用进行详细介绍,并对比分析了EDI模块更新前后的能耗、节能减排、经济效益和运行操作方面的不同,与MK-2模块相比,产水电导率进一步降低至0.06 μS/cm以下,且在节能减排和经济效益方面表现突出。

关键词: EDI, 除盐水, 混合离子交换, 水质, 节能, 经济效益