Elewa Mahmoud M, El Batouti Mervette, Al-Harby Nouf F
Arab Academy for Science, Technology and Maritime Transport, Alexandria P.O. Box 1029, Egypt.
Chemistry Department, Faculty of Science, Alexandria University, Alexandria 21526, Egypt.
Materials (Basel). 2023 Jul 7;16(13):4872. doi: 10.3390/ma16134872.
Another technique for desalination, known as membrane capacitive deionization (MCDI), has been investigated as an alternative. This approach has the potential to lower the voltage that is required, in addition to improving the ability to renew the electrodes. In this study, the desalination effectiveness of capacitive deionization (CDI) was compared to that of MCDI, employing newly produced cellulose acetate ion exchange membranes (IEMs), which were utilized for the very first time in MCDI. As expected, the salt adsorption and charge efficiency of MCDI were shown to be higher than those of CDI. Despite this, the unique electrosorption behavior of the former reveals that ion transport via the IEMs is a crucial rate-controlling step in the desalination process. We monitored the concentration of salt in the CDI and MCDI effluent streams, but we also evaluated the pH of the effluent stream in each of these systems and investigated the factors that may have caused these shifts. The significant change in pH that takes place during one adsorption and desorption cycle in CDI (pH range: 2.3-11.6) may cause problems in feed water that already contains components that are prone to scaling. In the case of MCDI, the fall in pH was only slightly more noticeable. Based on these findings, it appears that CDI and MCDI are promising new desalination techniques that has the potential to be more ecologically friendly and efficient than conventional methods of desalination. MCDI has some advantages over CDI in its higher salt removal efficiency, faster regeneration, and longer lifetime, but it is also more expensive and complex. The best choice for a particular application will depend on the specific requirements.
另一种脱盐技术，即膜电容去离子化（MCDI），已作为一种替代方法进行了研究。这种方法除了能提高电极的再生能力外，还有降低所需电压的潜力。在本研究中，将电容去离子化（CDI）的脱盐效果与MCDI的脱盐效果进行了比较，采用了新生产的醋酸纤维素离子交换膜（IEMs），这是其首次在MCDI中使用。不出所料，MCDI的盐吸附和电荷效率高于CDI。尽管如此，前者独特的电吸附行为表明，通过IEMs的离子传输是脱盐过程中一个关键的速率控制步骤。我们监测了CDI和MCDI流出物流中的盐浓度，但我们也评估了每个系统中流出物流的pH值，并研究了可能导致这些变化的因素。CDI在一个吸附和解吸循环中发生的显著pH变化（pH范围：2.3 - 11.6）可能会给已经含有易结垢成分的给水带来问题。在MCDI的情况下，pH值的下降只是稍微更明显一些。基于这些发现，CDI和MCDI似乎是很有前景的新型脱盐技术，有可能比传统脱盐方法更环保、更高效。MCDI在脱盐效率更高、再生更快和寿命更长方面比CDI有一些优势，但它也更昂贵、更复杂。特定应用的最佳选择将取决于具体要求。
