Water Resources Research Act Program

Details for Project ID 2019IL090B

Electrochemically-mediated adsorption systems for selective nitrate recovery: agriculture and the water-energy nexus

Institute: Illinois
Year Established: 2019 Start Date: 2019-06-18 End Date: 2020-05-31
Total Federal Funds: $10,000 Total Non-Federal Funds: $20,000

Principal Investigators: Dr. Xiao Su

Abstract: Excess nutrients are a major problem of concern for freshwater sources in the United States, especially nitrogen and phosphorus compounds from anthropogenic activities. In agriculture, nitrate from fertilizers eventually finds its way into aquifers and streams, becoming a problematic contaminant to treat by conventional technologies. Thus, efficient, affordable and robust purification technologies are needed for a range of nutrient remediation contexts, from point-ofsource treatment or remote in-situ devices to large-scale, centralized wastewater treatment facilities. We propose to develop and implement a conceptually new strategy for nutrient remediation and recovery that relies on electrochemically-modulated separation processes. These processes exploit redox-tunable molecular-level affinities of adsorbent materials towards target contaminants and require no additional chemical additives, only a mild source of electrical power. These processes can be operated over a wide range of scales, from simple hand-held devices to high-volume treatment facilities, without need for high-pressure or temperature swing operations. The design principles will focus not only on the fundamental binding of nitrate to our electrodes, but also on ensuring the ease and cost of fabrication of the electrodes themselves, as well as their assembly into practical devices for use both in individual households, and in more centralized facilities. The goal is to remove nitrate from contaminated water, while at the same time recovering this nitrate in up-concentrated form as a value-added commodity, for possible re-use in agricultural contexts. Important factors to be considered include: cyclic operational modes, energetics of the process, device fabrication, sources of electrical power, cycling stability, operation at different scales, among others.