Intensified acidophilic bioleaching of multi-metals from waste printed circuit boards (WPCBs) of spent mobile phones

BACKGROUND Waste printed circuit boards (WPCBs) are a resource containing a wide array of metals and are of great importance because their metal concentration is much greater than that in the ores. Previous studies have been devoted mostly to copper (Cu) bioleaching from WPCBs because it has the highest proportion ( similar to 10-30%) of all their component metallic elements. The present study focused on an intensified mixed meso-acidophilic bacterial leaching of multi-metals from WPCBs of spent mobile phones, with the system operating under high oxido-reductive potentials (HORPs). Inductively coupled plasma-optical emission spectrometry (ICP-OES), X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive X-ray (SEM-EDX) characterization indicated the WCPB sample had recoverable contents of Cu, aluminium (Al), nickel (Ni) and zinc (Zn) which were targeted for bioleaching.