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The Department of Chemical and Biological Engineering presents its fall 2025 seminar series featuring guest speaker Christopher G. Arges, principal chemical engineer at Argonne National Laboratory, who will present “Selective Ion Separations for Securing Critical Minerals and Nutrient Recovery.” This seminar will take place on Wednesday, October 1, from 3:15–4:30 p.m. in room 131 of Perlstein Hall.

Abstract

A 2019 National Academies Report highlighted that chemical separations account for 10–15 percent of the overall energy use in the United States. Because of their large energy footprint, there is a need to innovate new separations technologies that are more energy efficient while being environmentally benign. Electrochemical processes are enticing for chemical separations because of their low-exergy nature. They are also an emerging technology for securing critical mineral and material (CMM) supply chains without generating copious amounts of chemical waste. However, further adoption of electrochemical platforms for CMMs from primary and secondary sources requires additional improvements in the selectivity and permeability of the targeted ionic species.

This talk commences with a broad overview of various mechanisms for achieving selective ion separations in electrochemical processes. One notable strategy is to influence the speciation of the target ion of interest by exploiting its Pourbaix behavior and/or interaction with selective electrodes or resins. To that end, we have demonstrated pH-assisted electrochemical separations of copper and lithium using bipolar membranes in electrosorption processes. Selective capture of lithium occurred from geothermal brines while concurrently producing lithium hydroxide—which is the desired feedstock in the manufacture of lithium-ion batteries.

The talk concludes with mixed matrix anion exchange membranes for selective phosphate (i.e., nutrient) recovery from wastewater streams. Because phosphate rock availability is diminishing due to the greater use of synthetic fertilizers, there is significant interest in recovering phosphorus from agricultural runoff and other waste streams. Incorporating manganese oxide particles into poly (phenylene alkylene) anion exchange membranes amplified phosphate anion partitioning leading to improved phosphate selectivity. Overall, mixed matrix membranes, in-situ pH adjustment using bipolar membranes, and selective electrodes were amalgamated to facilitate selective ion separations.

Biography

Chris Arges is a principal chemical engineer at Argonne National Laboratory and a CASE senior scientist affiliate in the Pritzker School of Molecular Engineering at the University of Chicago. He was formerly a professor of chemical engineering at Penn State and Louisiana State University. Arges’s research interests are at the intersection of polymer science and electrochemical engineering. He earned his B.S. in Chemical Engineering at the University of �㽶��ý at Urbana-Champaign and a Ph.D. in Chemical Engineering at �㽶��ý Institute of Technology. Arges was a postdoctoral student in Pritzker School of Molecular Engineering at the University of Chicago. He is the recipient of the NSF CAREER Award, the Electrochemical Society-Toyota Young Investigator Fellowship, and the 3M Non-Tenured Faculty Award.