New electrochemical system enables efficient metal recovery from industrial wastewater

A research team at Tsinghua University led by Professor Huijuan Liu has developed a new electrochemical system that promises to revolutionize metal recovery from industrial wastewater. The research was published in Engineering.

Industrial wastewater poses significant environmental hazards due to heavy metal pollution. Current methods for metal recovery, such as electrodeposition, suffer from interfacial ion transport limitations, resulting in slow and low-quality recovery. In their study, the team proposed a novel approach that integrates a transient electric field (TE) and swirling flow (SF) to improve mass transfer and promote interfacial ion transport simultaneously.

The research team explored the effects of different operating conditions, including operation mode, transient frequency, and flow rate, on metal recovery. They discovered that the optimal conditions for rapid and efficient sequential recovery of copper in TE&SF mode were achieved with low and high electric levels of 0 and 4 V, a 50% duty cycle, a 1 kHz frequency, and a 400 L/h flow rate. The kinetic coefficients of TE&SF electrodeposition were found to be 3.5−4.3 times and 1.37−1.97 times that of single TE and SF electrodeposition, respectively.

To gain insights into the process, the team simulated the deposition process under TE and SF conditions. The results confirmed the efficient concurrence of interfacial ion transport and charge transfer, leading to rapid and high-quality metal recovery. The combined deposition strategy demonstrates not only effective metal pollution reduction but also promotes resource recycling.

This innovative approach overcomes the limitations of interfacial ion transport in conventional electrodeposition methods. By coupling a transient electric field with turbulent flow, the team successfully improves bulk and interfacial ion transport, thus enhancing the reaction kinetics. The synergy of the transient electric field and swirling flow achieves not only rapid metal recovery but also deposits with homogeneous compositions and uniform morphologies.

Furthermore, the system shows wide applicability in recovering metals with redox potentials higher than those of hydrogen evolution and water reduction. This capability allows for the high-value recovery of precious and heavy metals, making it a valuable asset for industries dealing with metal waste.

The research conducted by Professor Huijuan Liu and her team provides new insights into efficient metal recovery from industrial wastewater. Their findings open up possibilities for environmentally friendly and resource-efficient metal recycling processes, contributing to the reduction of pollution and the preservation of valuable resources.

The paper “Efficient Metal Recovery from Industrial Wastewater: Potential Oscillation and Turbulence Mode for Electrochemical System ” authored by Li Chen, Gong Zhang, Huijuan Liu, Shiyu Miao, Qingbai Chen, Huachun Lan, Jiuhui Qu. Full text of the open access paper: https://doi.org/10.1016/j.eng.2023.12.002. For more information about the Engineering, follow us on Twitter (https://twitter.com/EngineeringJrnl) & like us on Facebook (https://www.facebook.com/EngineeringJrnl).

About Engineering:

Engineering (ISSN: 2095-8099 IF:12.8) is an international open-access journal that was launched by the Chinese Academy of Engineering (CAE) in 2015. Its aims are to provide a high-level platform where cutting-edge advancements in engineering R&D, current major research outputs, and key achievements can be disseminated and shared; to report progress in engineering science, discuss hot topics, areas of interest, challenges, and prospects in engineering development, and consider human and environmental well-being and ethics in engineering; to encourage engineering breakthroughs and innovations that are of profound economic and social importance, enabling them to reach advanced international standards and to become a new productive force, and thereby changing the world, benefiting humanity, and creating a new future.