The scientists say their work represents proof-of-concept for the applicability of such systems for wastewater treatment and environmental protection. PHOTO/FILE
By BRENDA TATU
Using electrochemistry to separate different particles within a solution (also known as electrochemical separation) is an energy-efficient strategy for environmental and water remediation: the process of purifying contaminated water.
But while electrochemistry uses less energy than other, similar methods, the electric energy is largely derived from nonrenewable sources like fossil fuels.
The new studies by chemists at the University of Illinois Urbana-Champaign published in journal Nano-Micro Small have demonstrated that water remediation can be powered in part — and perhaps even exclusively — by renewable energy sources.
Through a semiconductor, their method integrates solar energy into an electrochemical separation process powered by a redox reaction, which manipulates ions’ electric charge to separate them from a solution like water.
“Global electrical energy is still predominantly derived from nonrenewable, fossil-fuel-based sources, which raises questions about the long-term sustainability of electrochemical processes, including separations. Integrating solar power advances the sustainability of electrochemical separations in general, and its applications to water purification benefit the water sector as well,” said lead investigator Xiao Su, a researcher at the Beckman Institute for Advanced Science and Technology and an assistant professor of chemical and biomolecular engineering.
Using this system, the researchers successfully separated and removed dilute arsenate — a derivative of arsenic, which is a major waste component from steel and mining industries — from wastewater.
The scientists say their work represents proof-of-concept for the applicability of such systems for wastewater treatment and environmental protection.
Redox-mediated electrosorption is a promising platform for selective electrochemical (EC) separations, due to its molecular selectivity, high uptake, and tunability for target ions. However, the electrical energy required is mainly generated by non-renewable energy sources, which limits its sustainability and overall impact to decarbonization.
Electrochemical (EC) separations have been proposed as an energy-efficient and modular technology that can contribute to the decarbonization of manufacturing and environmental processes.
Advances in redox-mediated electrosorption techniques, particularly with redox-polymers, can enable high separation performance for target ions in multicomponent mixtures and in dilute concentrations due to their remarkable selectivity, tunability, and reversible adsorption/desorption.
Redox-electrosorption has extended applicability for ion-selective recovery in industrial wastewater treatment, mining recovery, and environmental remediation. However, current global electrical energy is still predominantly derived from non-renewable fossil-fuel-based sources, which raises questions about the long-term sustainability of EC processes, including EC separations.
As such, direct integration with eco-friendly renewable energy, such as solar energy can provide a pathway for realizing the sustainability of electrochemically-driven separation processes.