(6bf) Investigating the Selective Removal of Anions and Cations in Electrodialysis/ Electrodialysis Reversal (ED/EDR)

Fresh water resources are inherently limited by their quantity, and it has drawn the world’s attention. Electrodialysis and electrodialysis reversal (ED/EDR) are two closely-related water purification processes which use an electrical field to propel ions through ion exchange membranes. The most effective use of these technologies has proven to be the production of potable water from brackish water resources. In brackish water resources as well as industrial water streams, water compositions differ, and removal of particular monovalent or divalent ions may be more desired than others. Therefore, removing ions at different rates under more controllable conditions is valuable. Selective removal of ions in an ED / EDR process can decrease the energy due to removing the target ions rather than unwanted ones. This experimental study, which investigates the nature of ion removal and the effects of operating parameters on the process, was conducted to explore the dominant empirical model on the selective removal of monovalent ions and divalent ions in the laboratory-scale ED process.

During my PhD studies, I have conducted the experiments in pilot scale EDR at the Brackish Groundwater National Desalination Research Facility (BGNDRF) in Alamogordo, NM. This set of experiments provided me a general idea regarding the effect of operating parameters on the removal of different ions in the EDR process. Utilizing this data, I designed, and built a complete laboratory scale ED system equipped with a complete data acquisition system. The reason that the data acquisition system was designed and used in this system was to provide continuous and accurate monitoring and recording the operating conditions during the entire experiments. The collected data was used in developing an empirical model to predict the removal of monovalent and divalent ions in the ED/EDR process at various operating conditions. The developed model can be widely used for full-scale electrodialysis operations for which removal of some of the specific ions is desired.

As an independent scientist, I will focus on improving the ED/EDR as well as other membrane-based desalination technologies in order to reduce the energy and cost of the process without impacting performance of these processes. Additionally, I will work on using renewable energies, specifically solar energy, to provide off-grid desalination systems for rural, remote off-grid areas to provide water for people who are suffering from fresh water scarcity.