Membrane-free electrodeionization using strong-type resins for high purity water production

作者：Hu, Jiayuan; Fang, Zhixing; Jiang, Xiaping; Li, Tianjun; Chen, Xueming^*

来源：Separation and Purification Technology, 2015, 144: 90-96.

DOI：10.1016/j.seppur.2015.02.023

• Membrane-free electrodeionization
• Desalination
• High purity water
• Resins regeneration
• Water dissociation

A promising membrane-free electrodeionization (MFEDI) process has been proposed for high purity water (HPW) production in our previous work. However, the employ of a large number of weak-acid resins in MFEDI limits this process for purifying the reverse osmosis (RO) permeate of tap water with a pH value below 6.0. In this work, a MFEDI system filled only with mixed strong-acid and strong-base resins was tested to desalinate the synthetic acidic RD permeate. Results demonstrated that the resins regeneration was achieved mainly by electrically enhancing water dissociation after a high current density was imposed to the resin layer. Both good purification and effective regeneration were achieved. The conductivity of effluent was 0.060-0.062 mu S/cm only. The energy consumption fluctuated in the range of 0.35-0.41 kW h/m(3) water and the water recovery reached 93.1%. The mixed concentrate collected during regeneration, with an average conductivity of 145 mu S/cm and a pH value of 6.5, could be returned to a pretreatment unit for recovery. No chemical was needed and no wastewater was produced. Repetitive experimental results showed the MFEDI system could work stably.

• 出版日期2015-4-15
• 单位浙江大学