电渗析浓缩模拟浓盐水工艺的实验研究

摘要

The demand of comprehensive utilization of sea water and the requirement of environment protection promote the development of technologies to concentrate salt water. The electrodialysis has been applied extensively to salt water concentration. The electrodialysis process is strongly affected by the membrane characteristics and the operating conditions. To investigate the performance of electrodialysis in concentrating salt water, the intermittent circulating electrodialysis experiments were carried out with a NaCl solution of 70 g⋅L-1, oriented to the target that concentration higher than 150 gNaCl⋅L-1⋅ while energy cost less than 120 kWh⋅(tNaCl)-1. The influence of solution flow rate, flow-rate ratio, temperature, and voltage on energy cost and concentrating ratio were examined. Experimental results show that the influence of concentrated solution flow rate and temperature on energy cost and concentrate ratio is ignorable, while the influence of the voltage and the flow-rate ratio is significant. The optimal membrane performance was obtained under a condition of 250 L⋅h-1, 2:3, 19 V and 30℃.%海水资源的综合利用和环境保护的要求极大地促进了淡化后浓盐水的处理技术的发展。电渗析是盐水浓缩广泛关注和应用的技术之一，膜性能和操作条件对电渗析过程特性有着重要的影响。实验研究了以模拟海水淡化浓水(含盐量70 g⋅L-1)为原料的间歇循环电渗析过程，以浓度150 g⋅L-1、能耗120 kWh⋅(tNaCl)-1，为目标，研究了浓室流量、浓淡室流量比、操作温度、操作电压对能耗和相对浓缩率的影响。实验结果表明，温度和浓室流量对实验结果影响不大，而电压和浓淡室流量比影响比较大，实验所得最佳操作条件为浓室流量250 L⋅h-1，浓淡室流量比2：3，电压19V和操作温度30℃。