Bioleaching of valuable metals from printed circuit boards (PCBs) using Enterobacter quasihormaechei isolated from
Banhi Halder1, Vinod Kumar Nigam1, Muthu Kumar Sampath1
1Department of Bioengineering and Biotechnology, Birla Institute of Technology, Ranchi, Jharkhand, India.
Abstract:
The current study employed the isolation of a novel metal-resistant bacterium, Enterobacter quasihormaechei (GenBank Accession No. OR659321) from raw printed circuit boards (PCBs) waste for its bioleaching potential. The bacterium shows promising recovery efficiencies of multiple important metals (Ag 87.5%, Al 60.53%, Mg 58.71%, Cr 56.52%, Ca 55.80%, Cu 55.03%, Mo 50%, Zn 46.36%, Ba 44.22%, Fe 34.54%, Ni 34.15% and Mn 28.22%) from PCBs waste at 37 °C, 150 rpm and 5-days of incubation period. Further confirmation of bioleaching was carried out by FTIR, FE-SEM, EDS and XRD, respectively. The oxidation-reduction potential (ORP) was also investigated, and it was found to be reduced during the bioleaching of electronic waste. Overall, the current study demonstrates that the bacterium, E. quasihormaechei, can recover multiple valuable metals from PCBs without chemical pretreatment or nutrient additives through eco-friendly and cost-effective bioleaching methods.
