Abstract

Silver (Ag) is a precious metal, which has a wide range of applications among a myriad of industries. The increase in the demand for silver has resulted in the depletion of primary sources of the metal. Biohydrometallurgy, also called bioleaching, a method used to recover metals using microorganisms without relying solely on chemicals, is a very promising sustainable approach for the extraction of various metals from primary and secondary sources. This study explores the use of biohydrometallurgy for recovering silver from a secondary source using comparatively Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. The results show that the two-step bioleaching with A. ferrooxidans was more effective and resulted in a better recovery rate for silver. These encouraging results demonstrate the potential of bioleaching as a sustainable technology to recover silver from solid form, and the justification for further study.

Keywords:Bioleaching; Biohydrometallurgy; Bacteria; Silver; Oxidation; Metal recovery