Bionanomining: biotechnological synthesis of metal nanoparticles from mining waste-opportunity for sustainable management of mining environmental liabilities

Mining is an important activity for many countries, especially some in development, such as Chile, where it is a pillar of its economy. However, it generates large impacts that are undesirable for the population such as the generation of polluting solid and effluents with a high content of heavy metals and metalloids, which are traditionally accumulated in deposits. In recent years, bionanomining emerged as a cutting-edge scientific-technological development associated with the application of micro- and macro-organisms to generate nanotechnological products by using mining and industrial wastes and wastewaters. Biomass of many species of bacteria, plants, algae and fungi have the ability to reduce or oxidise cations, which can physically be deposited as nanometric materials such as the nanoparticles. Nanoparticles are materials that are increasingly used, and therefore, their demand increase, based on the high surface area characteristics to improve thermal, electrical and optical properties of materials, and metallic ones have also antimicrobial activity. This review addresses the biosynthesis of metal nanoparticles, focusing on mining waste recovery strategies, which is an emerging reality in mining countries. Transformation of potentially hazardous waste into a valuable product through techniques that are eco-friendly is an opportunity to develop sustainably depressed or polluted sites.