The aim of this study was to compare leaching characteristics of metals from printed circuit boards (PCBs), taken from waste electrical and electronic equipment in the presence and in the absence of the iron-oxidizing bacteria, Acidithiobacillus ferrooxidans. A. ferrooxidans not only increases the leached concentration of Cu from the PCBs, but also inhibits the components of the 0K medium and leached Cu from forming precipitates such as libethenite (Cu2(PO4)(OH)), thereby assisting Cu recovery from the PCBs. In addition, the leached concentration of Pb from PCBs decreased in the presence of A. ferrooxidans, due to Pb forming amorphous precipitates. It is expected that Pb is not highly toxic to A. ferrooxidans. Consequently, A. ferrooxidans can be used as a cost-effective and environmentally friendly way to leach out valuable metals from PCBs as low-grade urban ore.
Stirred-tank leaching of coarse-grained waste, printed circuit boards with Acidithiobacillus ferrooxidans
