膜/电容脱盐(MCDI)特性研究

Study on desalination performance of membrane capacitive deionization

以NaCl溶液为除盐对象,采用控制变量法,考察电压、流量、温度和进水浓度对膜/电容脱盐（MCDI）除盐效果的影响以及再生方式对MCDI再生效果的影响.结果表明：MCDI的除盐率随电压和温度的升高而增大,随进水流量和浓度的增大而减小;综合考虑除盐率和能量利用效率,在电压1.2 V、流量5.0-7.5 m L·min-1、温度20-25℃、浓度50-250 mg·L-1时,MCDI的除盐性能最佳;再生时,反接方式再生效率最高但耗能大,断路方式几乎无再生效果,短接方式再生效率良好且无耗能,综合考虑短接方式最佳.

By taking NaCl solution as the desalination object,this paper discussed the salt removal efficiency of the Membrane Capacitive Deionization（ MCDI） using the variable control method under different voltages,flow rates,temperatures and inflow concentrations. The regeneration performance of three types of regeneration methods were compared. The results showed that the removal efficiency of the MCDI increased with the increasing of temperature and voltages,while decreased with the increase of flow rate and influent concentration. Considering the removal rate and energy efficiency,the optimal desalination performance of the MCDI occurred at the following conditions： the voltage of 1.2 V,the flow rate of 5.0 ~ 7.5 m L·min-1,the temperature of20 ~ 25 ℃ and the concentration of 50 ~ 250 mg·L-1. The regeneration efficiency reached the highest with reverse voltage,but requiring extra energy. It is also observed that there was nearly no any regeneration efficiency in an open-circuit way. Results also showed that the short-circuit way yielded the best regeneration efficiency with no energy consumption. It is concluded that the short-circuit way is the most promising solution by considering regeneration performance and energy consumption.