Toward Efficient Metal Recovery from Industrial Wastewater: An Electrochemical System in Potential Oscillation and Turbulence Mode

Abstract

Efficient metal recovery from industrial wastewater facilitates addressing of the environmental hazards and resource requirements of heavy metals. The conventional electrodeposition recovery method is hampered by the limitations of interfacial ion transport in charge-transfer reactions, creating challenges for simultaneous rapid and high-quality metal recovery. Therefore, we proposed integrating a transient electric field (TE) and swirling flow (SF) to synchronously enhance bulk mass transfer and promote interfacial ion transport. We investigated the effects of the operation mode, transient frequency, and flow rate on metal recovery, enabling determination of the optimal operating conditions for rapid and efficient sequential recovery of Cu in TE&SF mode. These conditions included low and high electric levels of 0 and 4 V, a 50% duty cycle, 1 kHz frequency, and 400 L·h−1 flow rate. The kinetic coefficients of TE&SF electrodeposition were 3.5−4.3 times and 1.37−1.97 times that of single TE and SF electrodeposition, respectively. Simulating the deposition process under TE and SF conditions confirmed the efficient concurrence of interfacial ion transport and charge transfer under TE and SF synergy, which achieved rapid and high-quality metal recovery. Therefore, the combined deposition strategy is considered an effective technique for reducing metal pollution and promoting resource recycling.