电容去离子
膜
选择性
化学
离子
水软化
二价
电极
离子交换
电容感应
无机化学
化学工程
分析化学(期刊)
软化
材料科学
色谱法
海水淡化
催化作用
有机化学
物理化学
复合材料
工程类
操作系统
生物化学
计算机科学
标识
DOI:10.1021/acs.est.9b00655
摘要
Capacitive deionization (CDI) is an emerging technology capable of selective removal of ions from water. While many studies have reported chemically tailored electrodes for selective ion removal, the selective removal of divalent cations (i.e., hardness) over monovalent cations can simply be achieved using membrane CDI (MCDI) equipped with ion exchange membranes (IEMs). In this study, we use both experimental and modeling approaches to systematically investigate the selective removal of Ca2+ over Na+. Specifically, the impacts of current density, hydraulic retention time, and feed composition on the selectivity of Ca2+ over Na+ were investigated. The results from our study suggest a universal correlation between the ratio of molar fluxes and the ratio of spacer channel ion concentrations, regardless of operating conditions and feed composition. Our analysis also reveals inherent and universal trade-off relationships between selectivity and the Ca2+ removal rate and between selectivity and the degree of Ca2+ removal. This fundamental understanding of the mechanism of selective ion removal in MCDI can also be applied to flow-electrode CDI processes that employ IEMs.
科研通智能强力驱动
Strongly Powered by AbleSci AI