STTR Phase II: Nano Functionalized Capacitive Deionization For Water Purification

The broader/commercial impacts of this Small Business Technology Transfer Research (STTR) Phase II project are in their beneficial implications for water, energy, economics and human health. This is by virtue of making high quality purified water affordable and therefore more available. The proposed onsite water purification technology is the third generation capacitive deionization technology. It would increase water quality by more facile removal of salts and total dissolved solids from water. Its compact, low maintenance device would be uniquely suitable for rural areas, factories, and buildings. The device would have low maintenance, low energy usage, and low wastewater, with no added brine waste, and would require low or no disposables or chemicals. It would be an alternative to the predominant technologies of reverse osmosis and ion exchange, which either generate excessive wastewater, use chemicals, or generate salt brine waste. Affordable purified water will also help prevent water contaminants caused diseases. The technology is expected to save water and energy in data centers, commercial buildings, utilities, and manufacturing. The intellectual merit of this project is in the development of a manufacturable, cost effective third generation capacitive deionization device consisting of electrodes, flow cells, and electronics. Further improvements will be made in water purification charge efficiency, energy usage, water recovery, and electrode lifetime. The bench scale electrode coating formulation developed during Phase I will be optimized against particle shedding to reduce electrical leakage. The electrode will be transferred from bench scale to a production scale capability in a roll-to-roll electrode manufacturing process. The electrodes will be packaged into cartridge holders designed for modular use in an easy-to-manufacture process. Functionalization of electrode pore surfaces will be optimized for capacitance and efficiency by means of both smaller and larger functional group molecules than those that were used in phase I. A cost-efficient power and fluid distribution architecture will be developed into a modular, scalable pilot to perform according to specifications provided by potential customers. The lifetime of the flow cell will be determined with regards to carbonate fouling and electronic operating conditions. Initial target is to remove a delta of total dissolved solids (TDS) of 2000 ppm or more from a contaminated feed. Another target is 4 liters per minute flow rate at 70% or more water recovery. 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.