Bio-extraction of valuable metals from spent lithium-ion and nickel-cadmium batteries using magnetotactic bacteria and its role in electronic waste management

Abstract

ABSTRACTThis study presents the bio-extraction and mineralization properties of 5 different Magnetotactic bacteria (MTB) to extract valuable metals from spent Li-ion and Ni-Cd batteries. The powdered spent batteries were incorporated for particle size, FTIR, XRD, and XRF analysis. Further, MTB (1 × 107CFUs/ml) was treated individually with the powdered battery sample, and the bioabsorption results showcased the successful removal of lead (98%), nickel (90%), cadmium (97%), zinc (100%), and lead/cadmium (33%) from MSR1, RJS2, RJS5, RJS6, and RJS7, respectively. In addition, the MAG1 consortium treatment effectively removed cadmium (98.5%) and lead (60%). Also, the MAG2 consortium treatment removed cadmium (100%), followed by copper (67%). Similarly, MTB treated with Ni-Cd battery showed the strains RJS5 and MSR1 removed 60% and 66% of cadmium; furthermore, RJS2 and RJS6 removed 72% and 71.4% nickel, respectively. Finally, the RJS7 strain removed 100% lead and 75% cadmium. However, the Ni-Cd battery treated with MAG1 showed effective removal of 67.07% copper and 65% cadmium. Similarly, the MAG2 consortium removed 87% lead and 71% cadmium. The final SEM-EDX and XRF analysis on the Li-ion batteries showed that the RJS2 and RJS5 strains removed zinc and lead effectively. Also, the RJS5 and RJS7 strains treated with the Ni-Cd battery showed better removal of lead and manganese, respectively. This is the first report on the Magnetotactic bacteria to be used for the bio-extraction of valuable metals from spent battery waste.

Keywords

• magnetotactic bacteria
• Li-ion battery
• Ni-Cd battery
• bio extraction
• biomineralization