Biotechnological strategies to recover value from waste

Abstract

The demand on especially clean energy metals is growing exponentially creating a clear need to diversify the metals supply. Metal recovery from various waste deposits could be one solution to provide needed metals for the society and at the same time reduce the environmental effects of waste. Bioleaching has been commercially applied for the recovery of valuable metals from sulfidic ores, tailings and metallurgical side streams. Bioleaching approaches are still at laboratory scale for other waste streams, such as waste incineration ash, metallurgical slags and electronic waste. Adapted bioleaching strategies have been suggested for industrial and consumer metal-containing waste streams to overcome the challenges with alkalinity, heterogeneity, toxic contents, and the lack of sulfur and iron source. Integration of bioleaching with other technologies as well as integration of target waste with other material streams is one means to improve the process performance to reach higher metal yields and kinetics. Bioleaching has shown potential to decrease energy consumption and carbon footprint compared to more conventional technologies in commercial scale, which increases its attractiveness as a future technology choice.