Antibacterial performance of electrodeposited Cu@Cu2O coatings on concrete using printed circuit board wastewater

Printed circuit board (PCB) wastewater was used to electrodeposit Cu@Cu2O composite coatings on the concrete surface to improve the antibacterial properties of sewers. The optimal current density was determined by surface analysis and bacteria inhibition experiments, and the effects of electrodeposition on the decontamination of PCB wastewater and recovery of copper element were investigated. The electrodeposited mortar specimens possessed good antibacterial abilities against Desulfovibrio, Thiobacillus thiooxidans and Escherichia coli (E. Coli) at a current density above 0.5 mA/cm2. Intact and smooth Cu@Cu2O coatings formed on the concrete surface as current density increased to 1.5 mA/cm2. However, further increasing the current density led to the formation of more needle-shaped build-ups and cracks. Thus, 1.5 mA/cm2 was determined to be the optimum current density taking into account the integrity of coatings, bactericidal property and the leaching rate of Cu2+ ions. Moreover, the chemical oxygen demand of PCB wastewater sharply decreased, and up to 85% of copper ions were recovered after reusing the PCB wastewater five times. The application of electrodeposition using PCB wastewater in the manufacture of antibacterial sewers and wastewater treatment holds great promise based on the estimated cost reduction and conceived environmental benefits.