电去离子(EDI)技术制备高纯水--两种内部水流程模型的比较  

Ultrapure Water Production by Electrodeionization(EDI)—Comparison of Two Models with Different Inner Flow Path

作　　者：赵健[1] 王建友[1] 吴志强[1] 边艳芳[1] 苏玉龙[1] 

机构地区：[1]南开大学环境科学与工程学院,天津300071

出　　处：《南开大学学报（自然科学版）》2010年第4期55-60,共6页Acta Scientiarum Naturalium Universitatis Nankaiensis

基　　金：天津市科技创新专项资金(08FDZDSF03200)

摘　　要：以添加了Ca^(2+)、Mg^(2+)的-级反渗透(RO)产水为原水,采用淡水一级两段、浓水一级一段的新型EDI模型制备高纯水.通过改变浓水流向,使其与淡水流在不同部位构成逆流,以达到提高淡水水质和防止硬度离子结垢的双重目标.研究表明,淡水第一段逆流模型较淡水第二段逆流模型在分离性能、过程能耗、预防结垢等方面更具优势.应用优选模型,在进水电导率为33～35μS/cm,进水硬度为11.7 mg/L(以CaCO_3计)的条件下,EDI的总脱盐率为99.8%,Ca^(2+)、Mg^(2+)的去除率均接近100%,耗电量为0.26 kW·h/m^3.持续85 h的实验过程运行稳定,产水电阻率17.4～17.8 MΩ·cm,膜堆未结垢.Taking Ca^2＋,Mg^2＋ added RO water as feed water, a specific inner flow path was adopted in EDI process for ultrapure water production, according to which the dilute stream had two flow passages while the concentrate stream just had one. In order to achieve goals of water quality improving and hardness precipitation preventing simultaneously, the flow direction of concentrate stream was changed to constitute a countercurrent in first and second flow passage of dilute stream respectively. It was proved that the model in which the first passage of dilute stream was countercurrent with concentrate stream performed better in hardness removal, energy consumption and scale averting than the other. With feed hardness of 11.7 mg/ L （as CaCO3）, the improved EDI process could give a total salt rejection of 99.8%. The hardness rejection was near 100% while the energy consumption was 0.26 kW·h/m^3. In durative experiment of 85 h, the steady product resistivity was between 17.4 and 17.8 MΩ· cm. No precipitation was found.

关 键 词：电去离子 硬度离子 结垢 

分 类 号：TQ150.1[化学工程—电化学工业]