Crushed and ground Printed Circuit Boards (PCBs) samples were characterized to evaluate copper, lead, and aluminum using morphological characterization by Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), and X-Ray Fluorescence Spectroscopy (XRF). Bioleaching experiments using Acidithiobacillus ferrooxidans bacteria with and without pH adjustment in the inoculum were carried out in a shaker at 30 ºC and agitation of 100 rpm for a total duration of 12 days. The XRF characterizations showed 0.12% lead, 3.72% copper, and 12.73% aluminum in the PCBs. The metal solubilization experiments indicated higher values of total metal solubilization when performed with initial pH adjustment in the inoculum preparation. However, these experiments did not show higher values of metal solubilization by bioleaching. Sequential bioleaching assays with A. ferrooxidans followed by bioremoval metals by mixed culture in the presence and absence of field 5Hz magnetic had a total duration of 24h in the bioreactor with recirculation. The sequential experiments of bioremoval using mixed culture after bioleaching with initial adjustment of inoculum pH without field application had 100% removal of Al, 27.34% for Cu, and 96.43% for Pb from the lixiviate medium, and with the field application indicated 100% removal of Al, 83.82% for Cu, and 98.27% for Pb. A similar bioleaching experiment without inoculum pH adjustment and without field application had 99.74% removal for Cu and 91, 92% for Pb. The field application indicated 100% removal for Cu and 95.76% for Pb. Bioreactors with a magnetic field don’t show better removals to all metals analyzed.
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