In an effort to develop alternate
techniques to recover
metals from waste electrical and
electronic equipment (WEEE), this
research evaluated the bioleaching
efficiency of
gold (Au),
copper (Cu) and
nickel (Ni) by two
strains of
Aspergillus niger in the presence of
gold-plated
finger integrated circuits found in
computer motherboards (GFICMs) and
cellular phone printed circuit boards (
PCBs). These three
metals were analyzed for their commercial value and their diverse applications in the
industry. Au-bioleaching ranged from 42 to 1% for
Aspergillus niger strain MXPE6; with the combination of
Aspergillus niger MXPE6 +
Aspergillus niger MX7, the Au-bioleaching was 87 and 28% for
PCBs and GFICMs, respectively. In contrast, the bioleaching of Cu by
Aspergillus niger MXPE6 was 24 and 5%; using the combination of both
strains, the values were 0.2 and 29% for
PCBs and GFICMs, respectively. Fungal Ni-
leaching was only found for
PCBs, but with no significant differences among
treatments. Improvement of the
metal recovery
efficiency by means of fungal
metabolism is also discussed..(AU)