SBIR Phase II: Addressing Freshwater Salinization and Freshwater Scarcity with a Chloride Selective Removal and Recovery System

The broader/commercial impact of this Small Business Innovation Research (SBIR) Phase II project is to comprehensively address issues related to water treatment, environment protection, and resource recovery through the development of a new desalination technology called a desalination battery. Steady growth in human population and rapid industrial development have led to greater demands for water production. At the same time, anthropogenic activities, agricultural practices, and the disposal of wastewater have led to salinization of natural freshwater resources. The desalination battery combines the functions of desalination and energy generation to reduce the energy and costs associated with desalination, addressing challenges at the intersection of the water-energy nexus. The goal of the proposed research is to accelerate the commercialization of the desalination battery by evaluating the effects of various solution components present in real feedwater types on the performance of the desalination battery. Successful development of the desalination battery will help to safeguard access to freshwater resources and ensure an adequate freshwater supply, which are essential to advance the health and welfare of the American public. The overall goal of this project is to commercialize a new desalination technology, a desalination battery, which is based on the patented use of Bi as a Cl-storage electrode in combination with a Na-storage electrode. Like conventional batteries, the desalination battery stores and releases energy during the charging and discharging processes, but they are also coupled with the storage and release of Na+ and Cl-. As the energy consumed during charging is recovered during discharging, the net energy required for desalination is drastically reduced. Furthermore, since Na+ and Cl- are removed via ion-specific electrode reactions, the desalination battery enables membrane-free desalination. While efficient removal of NaCl has been demonstrated, the effects of various other solution components present in real wastewater and seawater are still unknown. The goal of the proposed work is to accurately evaluate the effects of different salinities, pH conditions, and various inorganic and organic species present in real feedwater on the performance of the desalination battery and develop mitigation plans for any problematic components. The success of the proposed work is critical to perform accurate technoeconomic calculations to prioritize the most promising feedwater types to target and develop a tailored commercialization plan for specific applications. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.