In-situ Cu(II) enrichment and recovery from low-strength copper-laden wastewater using a novel electrically enhanced microbial copper recovery cell (MCRC)

Abstract

An innovative electrically enhanced microbial copper recovery cell (MCRC) was proposed in this study to achieve fast and efficient in-situ enrichment and recovery of copper (Cu) ions from low-strength copper-laden water. The unique design of the system enabled in-situ copper recovery without altering the properties of wastewater or introducing other undesired substances. The copper ions could be efficiently enriched and removed, and this process was greatly enhanced by the application of additional voltage. The MCRC obtained a maximum current density of 1.62 ± 0.01 A m−2, and exhibited outstanding copper removal efficiency of 95.4% with an initial copper concentration of 5 mg L–1 at an applied voltage of 0.8 V, as well as the copper removal rate significantly increased by 196%. Furthermore, it was found out that the removal efficiency maintained >93% when the initial copper concentration increased 4 times to 20 mg L–1, while the removal rate increased 380%, which indicated the high potential of the MCRC system for practical applications. The deposited copper at the cathode could promote the electrochemical catalytic activity, as which favored the electron transfer reaction and lessened the internal resistance by 91%. This MCRC system provided a potential and efficient treatment strategy to improve the enrichment and recovery of copper ions for low-strength copper-laden wastewater.