Chloride pollution has brought increasing concerns over environmental protection, drinking water safety, and the resilience of transportation infrastructure. Meanwhile, the emission of carbon dioxide has been broadly recognized as a dominant greenhouse gas causing a series of negative climate changes. The vision of this convergent project is to initiate and establish “Convergent Electrolysis-Electrodialysis System” as a viable engineering solution that can effectively mitigate the complex environmental-ecological-economic issues associated with the ever-growing chloride pollution in urban waterbodies, while reducing the emission of carbon dioxide. The system is designed to directly cut down the chloride discharge by upcycling waste salt in the regeneration stream of urban water softeners, and to stop the continuous chloride pollution by switching the deicing agent from polluting road salt to the eco-friendly sodium formate. Powered by renewable energy, the system synergistically combines the conversion of carbon dioxide and the reduction of chloride pollution, magnifying the environmental and ecological benefits. This fundamental research of addressing growing urban chloride pollution directly helps maintain and recover the dwindling health of national ecological/environmental systems. <br/><br/>The overarching objective of this project is to acquire the scientific understanding as well as the technological insights into the technical achievability, ecological suitability, and economic viability of the system with measurable impacts on curbing the real-world chloride pollution in urban areas. The study will advance knowledge that can be broadly applied to environmental engineering, electrochemistry, process engineering, polymer materials, technoeconomic analysis, life-cycle assessment, and policy learning. The convergent research team aims to: 1) achieve the seamless integration between electrolysis and electrodialysis; 2) acquire understanding of inexpensive electrocatalytic materials; 3) understand the complex ion transport required in both electrolysis and electrodialysis; 4) examine the comprehensive impacts of sodium formate as the new-generation deicer; 5) gain the insights into the life-cycle assessment and the techno-economic analysis; and 6) promote societal outcomes through policy learning and behavior.<br/><br/>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.