Selective Ion Removal from Water Using Flow-through Electrode Capacitive Deionization

Abstract

Capacitive deionization (CDI) is a promising technology that removes ions from solution using charged electrodes and requires less energy than reverse osmosis for removal of salt from low salinity or brackish water. The selective removal of toxic ions from water can be achieved by tailoring the electrode properties such as pore morphology and surface functionality, as well as cell operating parameters, reducing the cost of water treatment. Lawrence Livermore National Laboratory’s unique flow-through electrode CDI platform has demonstrated remarkable selectivity for removal of toxic nitrate in the presence of chloride and sulfate ions, as well as tunable preferential absorbance of monovalent over divalent cations based on pore size. In this talk, we will present our latest results including the development of a multi-scale model (FE + QMD) to help elucidate the mechanism(s) for ion selectivity in CDI. Fig. 1: Flow-Through CDI cell Funding was provided by Lawrence Livermore National Laboratory Directed Research and Development (LDRD) Grant 17-ERD-017. This work was performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344. IM Release Number LLNL-ABS-763510. Figure 1