摘要
通过对电去离子过程进行二维建模并求解,模拟了电去离子运行中阴阳膜的膜面水解离及其产物在床层中的传递过程.结果表明,由于阴膜界面上存在水解离催化基团,阴膜水解离程度要高于阳膜,过量的阴膜水解离产物H+能穿过电流湮灭区使得靠近阳膜的阳树脂再生而阳膜水解离产物OH-不能穿过电流湮灭区,导致淡室出口处阴膜附近的阴树脂的转化率极低.根据再生树脂对盐离子迁移的增强作用,阳盐离子去除率要高于阴盐离子,因此阴阳盐离子目标去除率同时达到的时候,阴膜产生了无效的水解离,此水解离在必要水解离之外.因此EDI电流效率低的主要原因是阴阳膜水解离程度的差异.
A numerical steady state model is established to simulate the process of EDI with the consideration of water dissociation.The full pictures of the ionic transportation,ion exchange and the water dissociation process of the EDI are obtained.It is found that there is an annihilation area where the currents carried by H＋（water dissociation product at anion-exchange membrane interface,AM） and OH-（water dissociation product at cation-exchange membrane interface,CM） combine and annihilate.Due to the fact that there is water dissociation catalytic group in AM,the water dissociation current of AM is much larger than that of CM.The result is that OH-can not transfer through the annihilation area while H＋can.At the outlet of dilute compartment,the anion resin at the area near the AM is much low.The result is that the difference of water dissociation intensity leads to the low removal efficiency of salt anions.
出处
《江苏科技大学学报（自然科学版）》
CAS
北大核心
2011年第4期390-395,共6页
Journal of Jiangsu University of Science and Technology:Natural Science Edition
基金
国家自然科学基金资助项目(20704020)
江苏省青蓝工程资助项目
关键词
电去离子
电渗析
水解离
膜分离
数学模型
electrodeionization
electrodialysis
water dissociation
membrane separation
mathematical model
