Extraction of Precious Metals from Industrial Waste Using Microbial Technology

This book discusses the methods of biorecovery of various metals and includes current challenges and prospects of biorecovery of metals. Millions of tons of electrical and electronic equipment wastes are being generated worldwide out of which a very small fraction is properly collected and recycled, while the majority ends up in landfills. Loss of critical raw materials in this represents an unnecessarily high cost to the economy and a pressing need to develop cheap and sustainable recycling process. Bacteria such as Cupriavidus sp. can tolerate high concentration of metals such as silver and extracellularly synthesize silver nanoparticles (AgNPs). Such solubilize metals owing to various metabolic products thus help in biologically recovering these resources. Biorecovery of metals is important due to the need for resource conservation. In certain electroplating industries especially involving precious metals such as silver, gold, platinum, and palladium, the wastewater contains adequate amounts of precious and valuable metals. A suitable wastewater treatment is required not only to remove the heavy metals but also to recover those precious and valuable metals for both growing economy and to reduce dependence on import and for environmental concerns.