电渗析法脱除氨法烟气脱硫浆液中的氟离子

利用异相膜电渗析装置去除氨法烟气脱硫浆液中的F~-。考察了脱硫浆液p H、F~-初始质量浓度、Cl~-初始质量浓度、膜堆两端电压、浓缩室和淡化室循环流量等操作参数对F~-去除效果的影响。实验结果表明:在酸性条件下,F~-去除率更高;脱硫浆液中F~-初始质量浓度越高,F~-去除率越高;Cl~-初始质量浓度较低时会增加F~-去除率,过高时又会降低F~-去除率。优化的操作条件为:膜堆两端电压25 V,浓缩室和淡化室循环流量300 L/h。一级电渗析进行100 min后,Cl~-去除率接近100%,F~-去除率只有47.3%。二级电渗析进行100 min时,F~-去除率达92.2%。一、二级电渗析F~-累积去除率达96.1%。

Removal of fluorine ion from slurry in ammonia flue gas desulfurization by electrodialysis

F^- was removed from the slurry in ammonia flue gas desulfurization using a heterogeneous membrane electrodialysis device. The operating parameters affecting F^- removal were studied,such as：slurry pH,initial mass concentration of F^- and Cl^-,applied voltage,circulation flow of concentrating chamber and desalination chamber,and so on. The experimental results showed that：Acidic condition was conducive to F^- removal;The F^- removal rate was increased with the increasing of initial F^- mass concentration and lower mass concentration of Cl^-,but decreased when the initial Cl^- mass concentration was too high. The optimum operation conditions were as follows：applied voltage 25 V,circulation flow 300 L/h. The removal rate of Cl^- and F^- was 100% and 47.3% after the first-stage electrodialysis for 100 min,and after the second-stage electrodialysis for 100 min,the removal rate of F^- reached 92.2%. The total F^- removal rate was 96.1% by the two-stages electrodialysis.