An electric current improves Cu and Ni leaching from waste printed circuit boards by immobilized Acidithiobacillus ferrooxidans MA-Y1

Abstract:

Objective Waste printed circuit boards (PCBs) contain about 40% non-ferrous metals, which is more than 40 times that of natural ores, and thus they are known as a veritable “urban mine”. To achieve efficient and green recycling of PCBs, this study developed a leaching system that can efficiently leach non-ferrous metals from PCBs.Methods Acidithiobacillus ferrooxidans MA-Y1 was used to construct a bioleaching system for PCBs. Additionally, an electric current was introduced to strengthen the Cu and Ni leaching from PCBs.Results The optimal leaching parameters were addition of PCBs at 80.0 g/L, particle size of 4.0 cm, liquid velocity of 2.0 L/min, and electric current of 70.0 mA. Under these conditions, the leaching ratios of Cu and Ni from PCBs were 84.0% and 75.3%, respectively, which represented increases of 15.8% and 17.1% compared with the case without electric current.Conclusion An electric current improves the ability of A. ferrooxidans MA-Y1 to recover Cu and Ni from PCBs.