Harnessing the power of the Sun for water remediation

Harnessing the power of the Sun for water remediation
by Brad Bartz
Los Angeles CA (SPX) Jul 25, 2023

In a significant stride towards sustainable environmental solutions, chemists at the University of Illinois Urbana-Champaign (UIUC) have successfully utilized solar energy to power a water purification process. This innovative method, which merges renewable energy with electrochemical separation, has demonstrated its potential to overhaul the existing energy-intensive systems in environmental and water remediation.

Electrochemical separation, a process that employs electrochemistry to distinguish and isolate various particles in a solution, has been a favored technique for environmental and water remediation due to its energy efficiency. However, the current practices for generating the necessary electric energy for this process majorly rely on nonrenewable, fossil-fuel-based sources. This reliance poses a significant challenge to the long-term sustainability of electrochemical processes, including separations.

Addressing this sustainability concern, the team at UIUC presented a method that integrates renewable solar energy into the electrochemical separation process, effectively bypassing the need for nonrenewable sources of power. Their strategy involves the use of a semiconductor that converts sunlight into the required electricity to power a redox reaction, responsible for separating particles from a solution based on their electric charge.

A key accomplishment of this project was the successful separation and removal of dilute arsenate from wastewater. Arsenate, a derivative of arsenic, constitutes a significant waste component of steel and mining industries, making its removal a pressing concern. The successful extraction of such a pollutant through a solar-powered process underlines the practicality of the developed system for wastewater treatment and environmental protection.

The concept of coupling renewable solar energy with electrochemical separation signifies a groundbreaking shift towards sustainability in water purification and environmental protection strategies. This innovative approach not only advances the sustainability of electrochemical separations but also brings substantial benefits to the water sector.

Lead investigator of the project, Xiao Su, a researcher at the Beckman Institute for Advanced Science and Technology, and an assistant professor of chemical and biomolecular engineering at UIUC, emphasized the significance of their work. He noted, "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."

The team's achievement underscores the viability of renewable energy sources in powering electrochemical separations. This development opens up new possibilities for sustainable and energy-efficient strategies in water purification and environmental protection, with the potential to substantially impact industries and communities worldwide.

Research Report:Redox-Functionalized Semiconductor Interfaces for Photoelectrochemical Separations